Contents

Foreword

Chapter1:Let’sBuildanHFDigitalStationAnHFdigitalstationboilsdowntothreeessentialpieces:aradio,acomputerandadevicethattiesthemtogether.

Chapter2:PSK31GetstartedwiththemostpopularHFdigitaloperatingmodetoday.

Chapter3:RTTYRTTYmaybeanoldoperatingmode,butit’sstillthechampwhenitcomestocontestingandDXhunting.

Chapter4:JT65You’llbeastonishedathowlowyoucangowithJT65.Highpowerandbigantennasaredefinitelynotrequired!

Chapter5:MFSKandOliviaWiththesetwomodesyou’llstillbechattingwhenalltheothershavegivenup.

Chapter6:PACTORWhenyourmessageabsolutelymustgetthrougherrorfree,PACTORisagreatwaytogo.

Appendix:HelpfularticlesfromthepagesofQSTmagazine

Foreword

InterestinamateurHFdigitalcommunicationsisgrowingatarapidrate.Onanygivenday,evenwhenpropagationconditionsarepoorandthebandsarepractically“closed,”youcanhearthesoundsofdigitalconversationstakingplace.ThefactthatmostamateursowncomputersispartofwhatisdrivingthepopularityofHFdigital.The

other major factor is that so many hams live in homes that suffer severe restrictions on the kinds ofoutdoorantennasthatcanbeinstalled–ifany.DigitalmodesallowtheseamateurstocommunicatewithlowpowerandcompromiseDantennas,lettingthemenjoyAmateurRadiowhenthey’dotherwisebeofftheairentirely.The only problem is that HF digital technology is a foreign concept to a substantial number of

operators.Theywanttotryit,butdon’tknowwheretostart.That’sthepurposeofGetOntheAirWithHFDigital.This book offers clear, often step-by-step instructions about how to set up an HF digital station –

everything fromattaching cables to configuring software.Even though software changes over time, theinstructionsprovidedinthisbookarelikelytoapplyacrossseveralsoftwareversions.GetOn theAirWithHFDigital emphasizes thehands-onapproach.Thegoal is togiveyouall the

adviceyouneedtotaketotheairwavesasquicklyandeasilyaspossible.

DavidSumner,K1ZZARRLChiefExecutiveOfficer2011

ChapterOne

Let'sBuildanHFDigitalStation

TheShortScoopAnHFdigitalstationboilsdowntothreeessentialpieces:aradio,acomputeranda

devicethattiesthemtogether.

TheHFTransceiver

TheradiorequirementsforHFdigitalaresurprisinglystraightforward.Youdon’tneedtorunoutandpurchaseaspecialradiowithsophisticatedfeatures.AllyouneedisanSSBvoicetransceiver.Period.Any transceivermadewithin the last20yearswillworkwellwithmostHFdigitalmodes.Frankly,

evenveryoldSSBtransceiverscanbepressedintoservice.Whenconsideringanolderradio,however,therearetwothingstokeepinmind:Stability—Oldertransceivers,especiallyradiosthatusevacuumtubes,maytendtodriftinfrequency.

Driftisdeadlytodigitalcommunications.IfyoumustuseanoldrigasyourHFdigitaltransceiver,youmayneedtoallowittowarmupforaslongas30minutespriortooperating.Transmit/ReceiveSwitchingSpeed—OnedigitalmodeknownasPACTORrequirestheradiotojump

fromreceivetotransmit(andback)inmilliseconds.Manyolderradioscanachievethis,butitishardontheir switching relays. I oncemanaged to use an ancientDrakeTR-4 transceiver tomake a PACTORcontact,butitsoundedasthoughtheradiowasabouttoshakeitselftopieces!Newerradioswithsolid-stateswitchingarebetterforthisapplication.Ifyourradiodatesfromabout1990to thepresentday,you’ll likelybe infineshape.Theserigsare

stableandmostincludeallthefeaturesyou’llneedforHFdigital.ThesingularexceptioninvolvessomeoftheinexpensiveSSBtransceiversdesignedforlow-power(QRP)operating.Theserigsaren’tusuallyintended for digital applications, so their stability may be questionable. They may also not offerconnectionstoexternaldevicesthroughjacksknownasports.

RadioPorts

Modern radios get along surprisinglywellwith computers and other external devices. In fact,mostmodern HF transceivers are designed with external devices in mind. They offer a variety of portsdependingonthemodelinquestion.NearlyeveryHFrigmanufacturedwithinthepastdecadeincludesan“accessory”portofsomekind.

Typicallythesearemultipinjacks(asmanyas13pins)thatprovideconnectionsforaudiointoandoutoftheradio,aswellasapin thatcauses theradiotoswitchfromreceiveto transmitwhenever thepinisgrounded.ThisisoftencalledthePTTorPushToTalkline.Somemanufacturersalsocallitthe“Send”line.TakealookatthetypicalaccessoryjackshowninFigure1.1.These accessoryports are ideal for connecting thekindsof interfacedevicesweuse tooperateHF

digital.InadditiontothePTTfunction,accessoryportsprovidereceiveaudiooutputatfixedlevels that

neverchangenomatterwhere theVOLUMEknob isset.This isahighlyconvenient feature thatyou’llappreciatewhenoperatinglateatnightaftereveryonehasgonetobed.YoucanturntheVOLUMEknobtozeroandstillhaveallthereceiveaudioyouneed!Beawarethatsomeradiomanufacturerslabelaccessoryportsas“data”or“digital”ports.Thiscauses

noendofconfusionbecausemodernrigsoftenoffertwotypesofconnections:atrueaccessoryportwithaudioand transmit/receivekeying linesandanotherport that allowsacomputer toactuallycontrol theradio.Theconfusionoccurswhenhamsattempttofigureoutwhichportstheyneedtouse.Let’scleartheair!ForthepurposeofgettingontheairwithHFdigital,theonlytypeofradio“control”wecareabout

is the ability to switch from receive to transmit and back again. That connection is available at theaccessoryport,eventhoughtheportmaygobyadifferentname.

The kind of control the transceivermanufacturers have inmind goesway beyond the act of simplyswitchingbetween transmit and receive.Theyare talking about the computer takingover almost everyfunctionof theradio; that’sadifferentanimalentirely.Fullcomputercontrolusually involvessoftwarethatdoesmanythingssuchasdisplayingandchangingthetransceiver’sfrequency,raisingandloweringtheaudiolevel,scanningmemoryfrequenciesandagreatdealmore.Somecomputercontrolsoftwareissoelaboratethattheradioitselfcanbeplacedoutofsightandallcontrolconductedatthekeyboardandmonitorscreen.ManyamateursusethiscapabilitytocontroltheirrigsremotelyovertheInternetatgreatdistances.Transceivers have separate ports for this type of computer interfacing, often referred to asCAT, or

ComputerAidedTransceiver,andthesearemostdefinitelyarenotaccessoryports.Onthecontrary,theyareportsstrictlydesignedtoswapdatawithexternalcomputers.Theycomeinseveralvarieties…TTL: Transistor-Transistor Logic. These ports require a special interface to translate the serial

communicationfromyourcomputertoTTLpulsesthatyourradiocancomprehend.USB: Universal Serial Bus. Although the consumer electronics world adopted USB years ago,

transceivermanufacturershavebeensomewhatslowertocatchon.RS232:This isaserialport thatcanbeconnecteddirectly toyourcomputer ifyourcomputerhasa

serial(COM)port.Mostmoderncomputershavedoneawaywithserialports,butyoucanuseaUSB-to-

serialconvertertobridgethegap.Ethernet: This port allows the transceiver to become a “network device,” just like your wireless

router,printer,etc.OnlyahandfuloftransceiversofferEthernetportsatthistime.Ifyouwant to setupcompletecomputercontrolofyour radio,we’lldiscuss someoptions thatwill

allowyoutodothis.Buttobeperfectlyclearandblunt,letmesaythis:TogetontheairandenjoyHFdigital, you do not need full computer control and you do not need to concern yourself with thistransceiverport.Theaccessory jack (orwhateveryourradiomanufacturercalls it) is theonlyportthatmatters.

What?NoRadioPorts?WhatifyourSSBtransceiverdoesn’thaveanaccessoryport?Noproblem.Youcanusethemicrophonejackasyourconnectionfortransmit/receiveswitchingaswellastheaudio

input. For the audio output, you can use the external speaker or headphone jack. This isn’t an idealsituation,butitworks.Infact,manyHFdigitaloperatorstakethisapproach.

DutyCycleWhen talking about your transceiver, we need to spend a little time discussing the concept of duty

cycle.AsomewhatcrudedefinitionofdutycycleisthetimethataradiospendsgeneratingRFoutputasafractionofthetotaltimeunderconsideration.InHFdigitalterms,thinkofdutycycleastheamountoftimeyourradioisgeneratingRFduringanygiventransmissioncomparedtotheamountofthetimeduringthesame transmission when RF output falls to zero. A 100% duty cycle would mean that your radio iscrankingoutRFcontinuouslythroughouttheentiretransmission;theRFoutputlevelneverfallstozero.

Now you may say, “I guess I’m always using a 100% duty cycle. After all, my radio is alwaysgeneratingRFwheneverI’mtransmitting.”Notnecessarily.Whenyouare transmittingdigital,CWorevenSSBvoice,yourrigmaynotbeoperatingata100%

dutycycle.ConsiderSSBvoiceasanexample.Wheneveryouspeakintothemicrophone,theRFoutputlevelchangesdramaticallyasyourvoicechanges.Itcangofrom100%outputtozeroinafractionofasecond.The same is true forCW.Whenever yourCWkey is open between the dots and dashes, your

transceiveroutputisatzero.Measuredoveraperiodoftime(yourtransmittingtime),thedutycycleofSSBvoiceisactuallyabout

40%;CWisoftenaslowas30%orevenlessifyouareaparticularlyslowsender.HFdigitalmodesalsovaryindutycycle.Somemodessuchasradioteletype(RTTY)pushyourradio

toadutycycleofnearly100%.Othersresultinmuchlowerdutycycles.Sowhyshouldyoucareaboutyourdutycycle?The answer is that your radio may not be designed for the type of punishment a high duty cycle

transmissioncaninflict.Whenyouoperateyourradioata100%dutycycle,youaredemandingthatitsfinalamplifiercircuitsproducethefullmeasureofoutput—whateveryou’vesetthatoutputleveltobe–fortheentiretimeyouaretransmitting.Theresultisheat,andpotentiallyalotofit.Applyenoughheattoacircuitforasufficientlengthoftimeandyou’llseecomponentsbegintofail,sometimesinspectacularfashion.Somemanufacturersdon’tconsiderthepossibilitythattheirSSBvoicetransceiversmightbepressed

intoserviceasdigital transceivers.Theydesign the radios to tolerate thedutycycleofa typicalvoicetransmission.IfyouusethissameradiotoenjoyahighdutycycledigitalmodesuchasRTTY,youcouldbeaskingtheradiotooperatewelloutsideitsdesignlimits—withunfortunateresults.Always read your transceiver manual before attempting to use the radio for digital operating. The

manufacturermay advise you to reduce theRFoutput by asmuch as 50%whenusing high duty cyclemodes.Thiskeepstheheatgenerationmanageable.Whenindoubt,orwhenyounoticethatyourradioisbecomingparticularlyhot,reducetheRFoutput.You’llfindthatdigitalmodesdon’trequireagreatdealofoutputpoweranyway,sochancesareyouwon’tnoticethe50%reduction.

TransceiverFiltersAnotherimportanttransceiverfeaturetoconsiderisreceivefiltering.Inmostcaseswe’retalkingabout

thefilters locatedin theIntermediateFrequency(IF)stageofyourradio.Thesecanbephysicalfilters;modulesthatpluginoraresolderedintotheradio’scircuitboard.ManymoderntransceiversuseDigitalSignalProcessing (DSP) at the IF stage rather thanphysical filters.TheadvantageofDSP is that it isoftendesignedtobecontinuouslyvariable.Thismeansthatyoucannarroworexpandthefilterwiththepushofabuttonorthetwistofaknob.Asyou’lllearnlater,mostpopularHFdigitalmodesusewidereceive-audiobandwidthsforreception,

soitisn’tstrictlynecessarytohaveanIFfilternarrowerthanthetypicalSSBvoicebandwidthofabout2.8kHz.AllSSBtransceiversmeetthisrequirement.Therearesomeimportantexceptions,though.IfyoudecidetotryyourhandatRTTYcontestoperating,

you’ll quicklydiscover that a2.8kHz IFbandwidth is entirely toowide.Youwon’tbe able to easilyseparateindividualsignalsinaseaofRTTYcontestchaos.InthisenvironmentyouneedtonarrowtheIFbandwidthtoatleast500Hz.Inultra-crowdedconditionsyoumayneedabandwidthasnarrowas300Hz.Theremaybeother situationswhereyou’llwant touseanarrower IFbandwidth.Let’s sayyouare

tryingtocommunicatewithaweakstationandamuchstrongerstationbeginstransmittingarock-crushingsignal about 1 kHz up the band. Your radio’sAutomaticGain Control (AGC) is going to respond bydropping your receiver sensitivity into the basement. The weak station will become weaker still, ordisappearaltogether.Itisn’tpracticaltoaskthegigawattstationtomove,soyouronlyalternativeistodramaticallynarrow

your IF bandwidth to the point where his signal is eliminated and only the weak signal remains.Continuously adjustable IFDSP filtering is terrific for this application.You can create an IF filter as

narrowas necessary andput it right on the signal you are trying to hear.With ultra-sharpDSP filters,everythingoutsidethepassbandiseffectivelygone.IfyourtransceiveralreadyhasselectableorvariableIFfilters,you’reallset.Ifnot,consideraddinga

500HzIFfilterifyourradiowillallowyoutodoso.Itcouldcostyouasmuchas$130,butitisagoodinvestmentinthefuture,especiallyforcontesting.

AFSKvsFSKHereisaninterestingpointthatoftencausesconsternationamongdigitaloperatorswhentheyconsider

theirHFtransceivers.Basic HF SSB transceivers typically offer at least three operatingmodes: Upper Sideband (USB),

LowerSideband(LSB)andCW.OthersincludeAMandevenFM.ForHFdigitaloperationUSBorLSBisallyouneed.That said,you’llalsonotice that someHFrigs includeadigitalmodeselection thatmaybe labeled

“RTTY,” “Digital” or “Data.” Here is where the gnashing of teeth begins because the way the radiobehaveswhenyouselect thismodecanvarydependingon thedesign. Inotherwords, these labelscanmeandifferentthingsondifferentradios.For instance, the “Digital”modemay simply control how the IF filters canbeused.The radiomay

forbidyoufromselectinganarrowIFfilterwhenyouareinoneoftheSSBmodes,butitwillsuddenlyrelent andallowyou to access anarrow filterwhenyouenter the“Data”mode. Itmayalso includeafunctionthat“looks”fortheincomingaudioattheaccessoryjackwheneveryouselectthe“Data”mode.Otherwiseitignorestheincomingaudioattheaccessoryjackentirely.Thisisodddesignbehavior,butithappens.

Whatismostimportantforourdiscussion,however,isthefactthatsomemanufacturersusethismodelabeltoindicatethattheradiowillswitchtoFSK.Whatdoesthismean?ThevastmajorityofHFdigitaloperatorsuseAudioFrequencyShiftKeyingorAFSK,although they

maynotrealizeit.TheaudiotonesfromtheirsounddevicesareappliedtotheirradiosandconvertedtoshiftingRFfrequenciesattheoutput,hencethetermAudioFrequencyShiftKeying.ButthereisyetanotherwaytocreateshiftingRF.Youcantakedatapulses(notsound)directlyfromthe

computerandusethosepulsestodirectlyshiftatransceiver’smasteroscillatorfromoneRFfrequencytoanother.Sincethereisnoaudioinvolved,thisisknownasFrequencyShiftKeyingorFSK.IsthereanadvantagetousingFSKvsAFSK?Notreally.Itismostlyamatterofconvenience.SomeHF

digital transceiverswillnotallowyoutousenarrowIFfiltersunlessyouoperateusingtheFSKmode(thisdesignquirkisindecline,though).The problem with FSK in amateur transceivers is that it is limited to shifting between only two

frequencies. Many amateur digital modes use more than two frequencies. PSK31 – the most populardigitalmode—doesn’tshiftfrequencyatall;itshiftsphase instead.TheonlycommondigitalmodethatcanbenefitfromtrueFSKisRTTYsinceRTTYsignalsonlyshiftbetweentwofrequencies.FSKasitexistsinAmateurRadiotransceiversisafeatureforRTTYaficionadosalone.Theironyis

thatitisimpossibletotellthedifferencebetweenaproperlymodulatedAFSKRTTYsignalandaRTTYsignalgeneratedbyFSK.Sowhybother?Again,theanswerisconvenience—theFSKRTTYoperatorneverhastoworryabout

sendingtoomuchaudiotohisradioandatthesametimeheisassuredofhavingfullaccesstoalltheIFfiltersthatmightotherwisebemissingifheweren’tusingthismode.Ifyourtransceiveroffersa“RTTY,”“Data”or“Digital”mode,readyourmanualcarefullyandfindout

exactlywhatthismeans.Chancesarethat“RTTY”meansFSK.“Data”or“Digital”likelymeansAFSK,althougheventhemanufacturersconfusetheterminology.You’llfindsomemanualsreferringtoAFSKasFSK.Theauthorsarenotwrong,strictlyspeaking.Afterall,regardlessofwhetheryou’reusingAFSKorFSKtheRFsignalfrequenciesattheoutputarestillshiftingbackandforth.Itis“frequencyshiftkeying”ineithercase.Thedifferenceisinthemethodyouusetocreatetheshiftysignals.Ifyou’reunsure,lookatthehookupdiagraminthemanual.Doesitshowdigitaltransmitaudiobeing

appliedtotheradioattheaccessoryormicrophonejack?Ifso,itisAFSK.Whenyouselectthe“Digital”or“Data”mode,you’rereallyintheSSBmode,butusingaudiotogeneratethefrequencychanges.Butifthemanualshowskeyingdatabeingsuppliedtoan“FSK”line,itisindeedtrueFSK.

Computers

Asthisbookwasbeingwritten,thecomputerworldwasenteringastateofflux.By“flux”Imeanrapidchange.Fromtheearly1980sthroughabout2005,thedesktopcomputerwaskingamongordinaryconsumers

andAmateurRadiooperators.Thisisacomputerinaseparate,stand-alonecaseconnectedtoamonitorscreen, keyboard andmouse. Inside the computer case there is a sound device of some sort, either adedicatedsoundcardorasetofsound-processingchipsonthemotherboard.Thecomputerconnectstoperipheraldevicesthroughtheuseofserial(COM)ports.From2005onwardwe saw two important changes.Onewas the fact that laptop computersbecame

morepowerfulandaffordable.TheotherwasthatserialportsdisappearedinfavorofUSBportsinbothlaptopsanddesktopmachines.By2010laptops(andtoalesserdegree,netbooks)begantodominateAmateurRadiostations.Ashams

upgraded their computers, they no longer saw the need for bulky desktop systemswhen sleek laptopswoulddoquitenicely.Asthisbookwenttopress,evenlaptopswerefacingstiffcompetitionfromtabletcomputerssuchas

theAppleiPad.InAmateurRadiostations,laptopsanddesktopsarestillthemostpopularcomputers,butthisislikelytochangeasmorehamapplicationsaredevelopedfortablets.

Fornow,however,ourfocuswillremainprimarilyonlaptopsanddesktops.Withthatinmind,whatkindoflaptopordesktopdoyouneedforHFdigitaloperating?Thegoodnews is thatmostHFdigital softwaredoesnot requirepowerfulcomputers.Anyordinary

off-the-shelf consumer-grade computer will do the job. If you are buying new, don’t overspend for apowerfulcomputeryouwon’tneed.Frankly,adecentusedcomputerthat’sonlyacoupleofyearsoldwillbemorethanadequate.Ifyou’rethinkingaboutasmallnetbook,becareful tocheckthespecifications.Somenetbooksdon’t

includeaudioportsandasyou’llseeshortly,audioportsarehighlyimportant.In termsof operating systems,mostHFdigital software iswritten forMicrosoftWindows.Manyof

theseprogramswerecreatedduringtheWindowsXPera,buttheyrunwellonbothWindowsVistaandWindows7.Someamateurshavereportedproblemswitholdersoftwarerunningunder64-bitWindows7,butinmyexperiencethisproblemisuncommon.ThereisHFdigitalsoftwareavailableforMacOSaswell,althoughnotasmuchvariety.Linuxusers

willfindanumberofHFdigitalapplications,too.

If you are considering a new or used computer (desktop or laptop), here are a few rule-of-thumbshoppingspecifications:•Theprocessorclockfrequency(“speed”)shouldbe1.5gHzorbetter.•Thecomputershouldhaveasmuchmemoryaspossible,notjusttorunthehamapplicationssmoothly,

buttheoperatingsystemaswell.ForWindowsVistaor7,I’drecommendatleast4GBofRAM;moreisalwaysbetter.•Either a built-inwireless (Wi-Fi)modemor anEthernet port.Although it isn’t necessary for ham

work,chancesareyou’llwanttoconnectyourstationtotheInternetfromtimetotime.Ifso,you'llneedawirelessmodemorEthernetporttodoso.•ACD-ROMdriveforloadingnewsoftwarethatisonlyavailableonCD(alesscommonneedtoday,

butdon’tsellyourselfshort).

TheRiseoftheTabletsIn2011theGartnerresearchgroupreportedasharpdeclineindesktopandevenlaptopcomputersales.

Nodoubtsomeofthisdeclinewascausedbythepooreconomy,butalargepartwasduetothemeteoricriseoftabletcomputers.TheAppleiPadwasamongthefirsttabletsoutofthegateanditcontinuestodominatethemarket.If

youownaniPad,orcantraveltoanApplestoretoseeoneintheflesh,you’llinstantlyunderstandwhy.Thesethin,slickcomputerswithgorgeouslybright10-inchscreensareperhapstheperfectplatformsformodern digital media. They can send and receive e-mail, display TV shows andmovies, browse theInternet, act as e-book readers, become game platforms and do a great deal more. iPads are highlyreliableandvirtuallyimmunetoviruses.Forhundredsofmillionsofpeoplethroughouttheworld, theyareidealgo-anywherecomputers.Beyondthegeniusofitsdesign,theiPadhasrisentotheconsumertechnologythroneonthepowerof

Apple’spopulariTunesstore,whichoffersmorethan100,000applications,knownasapps,forjustabouteverypurposeimaginable.

Other tabletmanufacturers are playing catch-up at this point.Amazon’s tablet is gaining ground andotherssuchastheSamsungGalaxyarecarvingouttheirmarketshares.Some developers have already released apps for HF digital, primarily for the Apple iPad. Most

notableamongthesearetheMultimodeandI-PSK31appscreatedbyLucaFacchinetti,IW2NDH.BothoftheseappsallowyoutosendandreceiveRTTYandPSK31—twoofthemostpopularHFdigitalmodes.WhiletabletsmayindeedbethefutureofamateurHFdigital,thereremainstheproblemofinterfacing

tabletstotransceivers.ThiscanbeabittrickyandonthenextpageIoffersomesuggestions.

TheImportanceofSoundWithfewexceptions,everycomputeryouarelikelytopurchasetodaywillincludeaeitheradedicated

soundcardorasoundchipset.ThisfeatureisabsolutelycriticalforHFdigitaloperationbecausemostofthemodesyou’llenjoydependonsounddevicestoactasradiomodems—modulators/demodulators.

TabletConnectionsWiththeuseoftabletcomputersbecomingmorewidespread,we’reseeinganincreasingnumberofamateursputtingthesedevicesto

workintheirstations.Whenthisbookwenttopress,themostpopulartabletbyawidemarginwastheAppleiPad.Aswediscussinthischapter,thereare

alreadyseveraliPadapplicationsavailableforHFdigital,specificallyforRTTYandPSK31.ThemainproblemwithusinganiPadforHFdigitalismakingtheconnectionstothetransceiverandkeyingthetransceiverbetween

transmitandreceive.TherearetwowaysofconnectingiPadstotheoutsideworld:•Themicrophone/headphonejack•Thedockingport

IfyoupurchaseanAppleCameraConnectionKitandplugitintothedockingport,youwillsuddenlyhaveaUSBconnectiontotheiPad.Unfortunately,thisdoesnotmeanthatyoucanpluginanHFdigitalUSBinterface.AUSBinterfacedrawsmorepowerthantheiPad

canprovide,sotheiPadwillgenerateanerror.AnalternativeistousetheCameraConnectionKitwithasounddevicedesignedforusewiththeiPadsuchastheGriffiniMic(http://store.griffintechnology.com).Theheadphone/microphonejackisanotheroption.Thisjackrequiresanunusualfour-conductorplug.Theconnectiondiagramisshownin

thissidebar.Youcanusethisdiagramalongwithafour-conductorplugtomakeyourowntransmit/receiveaudioadapter.ThealternativeistopurchaseonepremadefromcompaniessuchasKVConnectionatwww.kvconnection.com.(NotethatcablesforiPhoneswillworkforiPadsaswell.)

Nowthatyou’vesolvedtheaudioproblem,whataboutkeyingtheradio?TheiPadprovidesnomeanswhatsoevertoattachanykindofkeyingdevice.ThesolutionistousetheiPad’stransmitaudiotodothejob.IntheAppendixofthisbookyou’llfindaQSTarticlethatdescribesanHFdigitalinterfacedesignedbySkipTeller,KH6TY.HisDigitalVOXSoundCardInterfaceusesaVoiceOperatedSwitch(VOX)circuitthatkeystheradiowhenevertransmitaudioissentfromtheiPad.TigerTronicsmakesadevicethatoperatesonthesameprinciple.TheirSignaLinkSL-1+interfacealsousesaVOXkeyingcircuit.The

SL-1+isavailablefromTigerTronicsatwww.tigertronics.comatacostof$80.

The audio from your radio enters your computer via the sound device where it is converted(demodulated)todigitaldataforprocessingbyyoursoftware.Theresultsarewordsorimagesonyourcomputermonitor.Whenyouwanttotransmit,thissamesounddevicetakesthedatafromyoursoftware,suchasthewordsyouaretyping,andconvertsittoshiftingaudiotonesaccordingtowhatevermodeyou

are using. This conversion is a form of modulation. The tones are then applied to your radio fortransmission.So how important are sound devices?Well, no sound device = no HF digital! (Well, there is one

exception,whichwe’lldiscusslater.)Thesimplestbuilt-insounddevicesarethosefoundinlaptopsandtablets.Theyprovidetwoportsto

theoutsideworld:microphone(audioinput)andheadphone(audiooutput).TheseareperfectlyadequateforHF digitalwork.Desktop computers often have a similar arrangement, although the output port isusually labeled“speaker.”A“line” inputmayalsobe included for strongeraudio signals. Inall casestheseportscomeintheformof⅛-inchstereojacks.Some desktop computers offer sound cards that plug into themotherboard. These devices aremore

elaborate.Somesoundcardscanofferasmanyas12externalconnections.Attherearofyourcomputeryou may find LINE IN, MIC IN, LINE OUT, SPEAKER OUT, PCM OUT, PCM IN, JOYSTICK,FIREWIRE,S/PDIF,REARCHANNELSorSURROUNDjacks,justtonameafew.ForHFdigitaluse,theimportantjacksareMICorLINEINandSPEAKEROUT.

Later in this chapterwe’ll discuss how to connect these sound devices to your radio, but one itemneedstobebrieflymentionednow:theinterface.Asyou’llseelater,theinterfaceisyetanothercriticalcomponentbecause it is the linkbetween thecomputer and the radio.The reason tomention it now isbecausethetrendininterfacetechnologyhasbeentoincorporatethesounddeviceintotheinterfaceitself.AtthetimeofthiswritingthereareseveralinterfacesbycompaniessuchasmicroHAM,WestMountainRadio and TigerTronics that feature their own built-in sound devices. These interfaces are extremelyconvenientbecausetheyworkindependentlyofwhateversounddeviceyouhaveinyourcomputer.JustplugintheirUSBcablesandyou’regoodtogo.Itdoesn’tmatterwhatkindofcomputeryouareusing;theinterfacewillworkwithit.Youalsoavoidarat’snestofwiringbetweenthecomputerandtheradio.

Whetherthesounddeviceisinaplug-incard,asetofchipsonthecomputermotherboardoracircuitinsideaninterface,onequestionoftenarises:Doesthequalityofthesounddeviceaffectyourabilitytooperate?ThisisoneofthemostcommonquestionsamongHFdigitaloperators.Afterall, thesounddeviceis

secondonlytotheradioasthemostcriticallinkintheperformancechain.Apoorsounddevicewillburyweaksignalsinnoiseofitsownmakingandwillpotentiallydistortyourtransmitaudioaswell.Beforeyoudashouttopurchaseacostlyhigh-endsoundcard,orobsessoverthesoundchipsetinyour

interfaceoronyourmotherboard,askyourselfanimportantquestion:Howdoyouintendtooperate?Ifyou have amodest station and intend to enjoy casual chats and a bit ofDXing, save yourmoney.Aninexpensivesoundcard,orthesoundchipsetthatisprobablyonyourcomputer’smotherboardorinyourinterface,isadequateforthetask.Thereislittlepointininvestinginaluxurysounddeviceifyoulacktheradioorantennastohearweaksignalstobeginwith,oriftheycannothearyou.Ontheotherhand,ifyouownthestationhardwarenecessarytobecompetitiveindigitalDXhuntingor

contesting,agoodsoundcardcangiveyouanedge.Thisisparticularlytrueifyouareusingasoftwaredefinedradio.Soundcardperformanceiscriticalforthisapplication.In2007theARRLundertookanevaluationof11commonsoundcardmodels.Thestudywasperformed

byJonathanTaylor,K1RFD,andtheresultswerepublishedinthe“ProductReview”sectionoftheMay2007issueofQST.Asyou’dexpect,thehigh-endsoundcardscameoutontop,butthinkcarefullybeforeyoureachforyourwallet.Don’tbuymoreperformancethanyoureallyneed.

SoftwareWhenwe’re talking about putting together anHF digital station, a brief word about software is in

order.Isay“brief”becauseitisn’tpracticaltodiscusssoftwareindetailwithinthepagesofaprintedbook.

Softwareevolvestoorapidlyforabookthathasausefullifetimemeasuredinyears.Anyspecificdetailswould be obsolete almost before the book left the printing press. Instead, let’s talk about software inbroadstrokes,beginningwithoperatingsystems.As I mentioned earlier, most computers in Amateur Radio stations are running on some form of

MicrosoftWindows.Asof2015quitea fewamateurswerestillusingWindows7,but themigration toWindows8waswellunderway.By2016itislikelythatmostWindowsuserswillberunningWindows8

orthenewerWindows10.AppleMacintosh owners are obviously quite fond of the variousMacOS incarnations, which have

proventhemselvestobeefficientandreliableoperatingsystems.TheuniverseofMacusersisgrowing,butAmateurRadiosoftwaretitlesfortheMacarestillfewinnumber.TheLinuxoperatingsysteminitsvariousversionsenjoysaloyalfollowingamongamateurswholike

writing their own software and tinkering at the operating system level. Like the Mac, there is hamsoftwareavailable,buttheofferingsaresomewhatsparse.ThethreeoperatingsystemshavetheirvocaladvocatesandI’dbeafooltochampiononeoveranother.

AllhavetheiradvantagesanddisadvantagestoconsiderfromanAmateurRadiopointofview.WindowsPro:Sheervariety.MostAmateurRadiosoftwareiswrittenforWindowssoyouhavearichselection

ofcompatiblesoftwaretochoosefrom.Con:BecauseofthewidespreaduseofWindows,itisafavoritetargetforhackers.Anti-virussoftware

isamustand thiscansignificantlyhamper theefficiencyofWindows andcauseotherannoying issues.Also,Windowscanbeexpensiveifpurchasedandinstalledseparately.MacOSPro: Stability and performance. Highly intuitive and easy to use. Also, hackers have only rarely

targetedMacOS.Con:MacOS runsonlyonAppleMacintoshcomputers.ItcanbemadetorunonPCs,but it isn’tan

exerciseforthefainthearted.AmateurRadiosoftwareforMacOSislimited.LinuxPro:Opensourceandfreeofcharge.Dependingontheversion,canbequiteefficientandpowerful.

Becausetherearesomanyversionsinthefield,hackersgenerallydon’tbotherdesigningvirusesforit.Theyprefereasierprey.Con:DirectorystructureandcommandsmaybeverydifferentcomparedtoWindows.AmateurRadio

softwareselectionisverylimited.Beyond the operating systems,we have specific software forHF digital operating. In the beginning

programs were designed for one specific mode, such as DigiPan for PSK31 (www.digipan.net) orMMTTYforRTTY(http://hamsoft.ca/pages/mmtty.php).Whilemode-specificsoftwarestillexists,thetrendhasbeenstronglyinfavorofmultimodesoftwarethatcanoperatemanydifferentHFdigitalmodes.

Themostpopularmultimodeapplicationsare…•Windows

MixWhttp://mixw.netMultiPSKhttp://f6cte.free.fr/index_anglais.htmFldigiwww.w1hkj.com/Fldigi.html

•MacOScocoaModemwww.w7ay.net/site/Applications/cocoaModem/MultiModewww.blackcatsystems.com/software/multimode.html

•LinuxFldigiwww.w1hkj.com/Fldigi.html

WiththeexceptionofMultiModeandMixW,alloftheaboveareavailableforfreedownloadingontheweb. Until late 2011 Ham Radio Deluxe, another popular program for Windows was free fordownloadingatwww.iw5edi.com/software/ham-radio-deluxe-5-download-links. It isstillavailableatthissite,butthecompanyhassincechangedhandsandHamRadioDeluxeisnowacommercialproduct.If you want the latest commercial version, which includes customer support, you can purchase it atwww.ham-radio-deluxe.com/.

TheInterface—theFullStory

If you’re likemost amateurs, you alreadyownmost of the componentswe’vediscussed so far.Youprobably have an HF transceiver and, like 90% of most US households, you have a computer in

residence.TheonepieceofhardwarethatyoumaynotownistheoneitemthatbringsthesecomponentstogethertocreateanHFdigitalstation:theinterface.

Atrockbottomaninterfacehasonlyonejobtodo:toallowthecomputertotoggletheradiobetweentransmitandreceive.Itachievesthisbyusingasignalfromthecomputer toswitchonatransistor(seeFigure1.2).Thistransistor“conducts”andeffectivelybringsthetransceiver’sPTT(PushtoTalk)linetogroundpotentialorveryclosetoit.WhenthePTTlineisgrounded,thetransceiverswitchestotransmit.When the signal from the computer disappears, the transistor no longer conducts and the PTT line iselectricallyelevatedaboveground.Theresultisthatthetransceiverreturnstothereceivemode.Thesignalfromthecomputerappearsataspecificpinonaserial(COM)orUSBport.YourHFdigital

softwaregenerates the signalwhenyou clickyourmouseonTRANSMITor some other buttonwith asimilarlabel.If an interface can be so straightforward, couldn’t you just build your own?Yes, you could.Many

amateurs enjoyHFdigitalwith simple interfaces like theone shownhere. Inaddition to the switchingcircuitinFigure1.2,theyconnectshieldedaudiocablesbetweenthecomputerandtheradiotocarrythetransmitandreceiveaudiosignals.SeeFigure1.3.InFigure1.3you’llnotethattheaudiolinesinclude1:1isolationtransformers.Thereasonforthisisto

avoidthedreadedgroundloop.Agroundloopresultswhencurrentflowsinconductorsconnectingtwodevices at different electrical potentials. In yourHF station the conductors in question are usually theaudiocablesrunningbetweentheradioandthecomputer.Agroundlooptypicallymanifestsitselfasahumthatyou’llhearinyourreceiveaudio,orthatother

stations will hear in your transmit audio. The hum can be so loud it will distort the received ortransmittingsignals,makingdigitalcommunicationimpossible.Theisolationtransformerseffectivelybreakthegroundlooppathwhilestillallowingtheaudiosignals

toreachtheirdestinations.Thesetransformersareinexpensive,usuallysellingforlessthan$3eachfromsourcessuchasRadioShack.

ToRollorNottoRollTherearegood reasons to rollyourown interface, thecost savingsbeingchief among them.On the

other hand, if you purchase an interface off the shelf you’ll be able to benefit from enhanced designfeatures,dependingonhowmuchyouwanttopay.Theshortlistofusefulfeaturesincludes…•IndependentAudioLevelControls.Theseareknobson thefrontpanelof the interface thatallow

youtoquicklyraiseorlowerthetransmitorreceiveaudiolevels.Manyamateursprefertomanagetheaudiolevelsinthisfashioncomparedtodoingitinsoftware.•CWKeying. Full-featured interfaces handlemore than just HF digital. They can also use keying

signals from thecomputer tosendMorsecodewithaseparateconnection to the transceiver’sCWkeyjack.ThisallowsyoutosendCWfromyourkeyboardrather thanwithahandkey,ausefulfeatureforhigher-speedCWexchangesduringcontests.•FSKKeying.IfyouwanttooperateRTTYwiththeFSKfunctionofyourtransceiver,assumingyour

rigofferssucha function, theFSKkeyingfeature translateskeyingsignals fromyourcomputer into theMARK/SPACEdatapulsesnecessaryforFSKRTTY.•MicrophoneInput. IfyouaremakingHFdigitalconnections toyour radio through themicrophone

jack rather than the rear panel accessory port, you’ll need to unplug the interface cablewhenever youwant to use your microphone for a voice conversation. To make operating more convenient, someinterfacesallowyoutokeepyourmicrophonepluggedintotheinterfaceatalltimes,switchingbetweenyourmicrophoneorcomputerasnecessary.•TransceiverControl.Rememberthatabasicinterfacedoesnotallowyourcomputertotrulycontrol

your radio, except in the sense that it can switch your radio between transmit and receive. Deluxeinterfacesincludetheextracircuitryneededtoallowfullcomputercontrolofyourtransceiver.SometimesreferredtoasCAT(ComputerAidedTransceiver),thisisaseparatefunctionthatpassesalltheavailablecontrolsfromyourradiotoyourcomputer.Dependingonthetypeoftransceiveryouownandthesoftwareyouareusing,CATallowsyoutochangefrequency,raiseandlowerpowerlevelsandmuchmore.IfyourtransceiverhastheabilitytoconnectdirectlytoyourcomputerthroughanRS-232serialconnection,USBcableorEthernetport,youdon’tneedtheCATfeature.TheCATfunctionisprimarilyintendedforradiosthatusetransistor-transistor(TTL)signalsforcontrol.ManufacturersselltheirownCATinterfaces,butthey tend to be expensive. An interface with CAT functionality brings everything together in oneaffordablebox.•Built-inSoundDevice.Aswediscussedearlier, several interfacedesigns includeabuilt-insound

device. This is particularly handy in that it liberates the sound device in your computer for otherfunctions. You can enjoymusic on your computer, for example, without having to worry that you aremeddlingwith thesound levelsyou’vesetup forHFdigitaloperating. Inaddition,an interfacewithabuilt-insounddevicegreatlyreducesthenumberofcablesconnectingthecomputerandradio.Theaudiosignals,aswellastransmit/receivekeyingfunctions,areallcarriedoverasingleUSBcable;therearenoconnectionstoyourcomputer’ssoundports.

•Pre-MadeCables.Mostcommercial interfacemanufacturers includecablesspecificallywired foryour radio free of charge, or offer them at an additional cost. This significantly reduces the hassle ofwiringyourHFdigitalstation.At the time of this writing, a basic off-the-shelf interface costs about $50; a multi-featured deluxe

interfacerunsashighas$400.You’llneedtoshopamongthemanufacturerstofindaninterfacethathasthefeaturesyoudesireatacostyouarewillingtopay.Themostpopularinterfacemanufacturersinclude...microHAM:www.microham-usa.com

MFJ:www.mfjenterprises.comTigerTronics:www.tigertronics.comWestMountainRadio:www.westmountainradio.comRigExpert:www.rigexpert.com

PuttingitallTogetherIfyou’vechosenaninterfacewithabuilt-insounddevice,assemblingyourstationisrelativelyeasy.

You’ll need a set of audio and PTT cables to connect the interface to your transceiver, either at themicrophoneandheadphonejacks,orattheaccessoryjack.AsI’vealreadymentioned,youcanpurchasethiscablefromthe interfacemanufacturerormakeyourown.TheUSBcablefromthe interfacesimplyplugsintoyourcomputer.TheUSBconnectiontoyourcomputercanbealittletrickyinonerespect,though.Whenyouplugthe

USB cable into the computer for the first time, the computer may attempt to load and run a driverapplicationsoitcan“talk”toyourinterface.Thisdrivermayalreadyexistonyourcomputer,oryoumayneed to load it fromaCDsuppliedby themanufacturer.Once thedriver is loaded, the computerwillrecognizetheinterfaceeverytimeyouplugitinthereafter.EventhoughtheinterfaceisconnectingtoyourcomputerthroughaUSBcable,itisdependingongood

old-fashioned serial communication just as though the connectionhadbeenmade throughaCOMport.TheinterfaceaccomplishesthisbycreatingavirtualCOMportinyourcomputer.Inotherwords,itusessoftwaretoemulatethefunctionofaCOMport.Why is it important for you to know this?The answer is that your digital softwarewill need to be

configuredso that it “knows”whichCOMport touse forPTTkeying,CATfunctions,etc.Thatmeansyou’llneedtoknowthisaswell!InWindowsitisamatterofgoingtotheControlPanelandhuntingdowntheDeviceManager icon.

Onceyou’vestartedDeviceManager,clickon thePortsectionandyou’ll seeallyourcomputerportslistedinorder.Lookforaportlabeled“USBSerialPort”or“VirtualCOMPort”(seeFigure1.4).Nextto it you’ll see aCOMnumber.Write this number down because you’ll need to enter itwhen you’resettingupyourHFdigitalprogramanditasksforthe“serialport”or“PTTport”(Figure1.5).

When the computer recognizes the USB interface, it also recognizes the sound device within theinterface. Itwill consider this device as another sound unit, just as though you had installed a secondsoundcardinsidethecomputer.(Thecomputerdoesn’tknowthatthissounddeviceissittinginaboxafewfeetawayanditdoesn’tcare!)Again,thisisimportanttounderstandbecausewhenyousetupyoursoftwareyoumayneedtospecifywhichsounddevicethesoftwareshoulduse.Obviouslyyouwillneedtoselectthesounddeviceinyourinterface.Mostsoftwareapplicationshavedrop-downmenusthatwilllisttheavailablesounddevicesautomatically.Don’texpecttoseeyourinterfacedevicelistedbybrandname.Instead,itmayshowupas“USBSound,”“USBAudioCodec”orsomethingsimilar.

Non-USBInterfacesIfyourinterfacedoesn’thaveaUSBconnection,itlikelyusesatraditionalserialconnectioninstead.If

yourcomputerhasaserial(COM)port,youneedonlyattachaserialcable(typicallyacablewith9-pinplugsatbothends)betweenthecomputerandtheinterface.InmostcomputerstheseserialportsfallinarangebetweenCOM1andCOM4.Plugyourserialcable

intoanavailableportanduseabitoftrialanderrortofindoutwhichoneyou’veselected.StartyourHFdigitalprogramandgototheconfigurationmenu.Entera“1”intotheCOMportselectionboxandthenclickontheTRANSMITbuttoninyoursoftware.Ifyourtransceivergoesintotransmit,congratulations—you’vefoundthecorrectCOMport.Ifnot,try2,3,4,etc.

ButWhatifYouHaveaSerialInterfaceandYourComputerDoesn’t

HaveSerialPorts?

Serialportsaregoingthewayofthedinosaurs.You’dbehardpressedtofindadesktopPCwithserialportstoday;inlaptopstheyarenonexistent.If your interface requires a serial cable, you have a problem. Fortunately, there are two solutions

available.(1)Ifyouownadesktopcomputerthatlacksserialports,youcanpurchaseaserialportcardforless

than$25.Thecardinstalls intheslotsonthecomputermotherboardandoffersoneortwo9-pinserialportconnectionsontherearpanel.

(2)Ifthethoughtoftinkeringinsideyourdesktopcomputerfillsyouwithdread,orifyouownalaptop,youcanuseaUSB-to-serialadaptercable.Atoneendofthecableyou’llfindamaleUSBplug;attheopposite end is a 9-pin (DB-9)male serial connector.Whenyouplug the cable intoyour computer, itcreatesthe“virtualCOMport”describedpreviously.Theseadaptercablesarecommonlyavailableandcostlessthan$20.

ManagingtheAudioConnectionsIfyouownaninterfacewithabuilt-insounddevice,you’llneedtoconnect the transmitandreceive

audiocablesbetweentheinterfaceandthetransceiver,eitheratthemicrophoneandheadphonejacks,or

attheaccessoryjack.Ifyourinterfaceisofthesimpletransmit/receiveswitchingvariety,theoneorbothsetsofaudiocablesmayhavetogoallthewaybacktothecomputer.Eventhoughyou’reusingshieldedaudiocables,thereisthepotentialfortroublewhenRFisintheair.

Thisisespeciallytruewhenyourstationantennaisclosetoyouroperatingposition.Theaudiocablescanactlikeantennasthemselves,pickingupRFandwreakinghavoconyourstation.I’veseensomeinstanceswhere thecomputer shutdownor resetwhenever the transceiverwaskeyed. Inotherexamples theRFenergymixedwiththetransmitaudioandresultedinahorrendouslydistortedoutput.IfyoususpectyouhaveanRFinterferenceprobleminyourHFdigitalstation,youcandiagnoseitby

reducingyouroutputpowerandobservingtheresults.If100Woutputgivesyougriefbut50Wissmoothassilk,youclearlyhaveanRFinterferenceissue.Presumablyyou’vekeptyouraudiocablesareshortaspossible.Stringingup20-foot-longaudiocables

betweentheradio,theinterfaceandthecomputerisjustaskingfortrouble.Butifyouraudiocablesareofreasonablelengthandyoustillsufferinterference,itistimetobuysome

toroid cores. These are circular donuts made of a powdered iron and epoxy mixture. They come invarioussizesandareratedforsuppressionatvariousfrequencies.ForHFapplications,Type61toroidsareamongthemosteffective.TosuppressRFonanaudiocable,wrapthecablethroughthetoroidatleast10timeswithevenlyspacedturns.Withtherighttoroidintherightplace,youcangreatlyreduceoreliminateRFinterference.Forsevere

casesyoumayneedtoplaceatoroidoneverycable.

You’lloftenseeused toroids for saleathamfest fleamarkets,butdon’tbuyaused toroidunlessyouknowthetypeofmaterialitcontains.Whenindoubt,buytoroidsnewfrommanufacturerssuchasAmidonatwww.amidoncorp.com.Avoidsnap-onferritecores.Whiletheyarecertainlyeasytouse,theyarenotaseffectiveastoroidsthatyouwindyourself.

SettingUptheTransceiverMuch of the advice that follows depends on what sort of transceiver you own and what kind of

interfaceyouareusingtocreateyourHFdigitalsetup.Whenindoubt,alwaysconsultyourtransceiverandinterfacemanuals.If your interface is connecting to the radio through the transceiver accessory port, see if there is a

function in the transceiver to adjust the accessory audio input and output levels. If it exists, this is aconvenientwaytoestablish“baseline”audiolevelsfortheradio.Ofcourse,youcanalsoadjustaudiolevelsatyourcomputersandpossiblyatyourinterface(dependingonthekindofinterfaceyoupurchase).

Ifitseemsasthoughyouaren’tgettingenoughaudiofromtheradio,orifitseemsthatyoucan’tdrivetheradio to full output regardlessof the computeror interface settings, check these transceiver settings aswell.

AudioOverdriveSpeaking of driving rigs to full output, we need to discuss the danger of audio overdrive.Without

questionthisisoneofthemostcommonissuesamongnewHFdigitaloperators.Regardlessof the typeofdigitalmodeyouenjoy, there isanalmost instinctual tendencyamongnew

operators toadjust their transmitaudio levelswhileonlywatching their transceiver’sRFoutputmeter.They place their radios into the transmit mode and crank up the audio levels at their computers orinterfacesuntil they see a satisfying100WRFoutput.At thatpoint theyassume theyare finishedandreadytotaketotheairwaves.Thisisknownas“tuningformaximumsmoke.”Theycouldnotbemoremistaken!First of all, most HF digital modes do not require 100W of power to make contacts. One of the

benefitsofHFdigital,infact,isthatyoucanmakecontactsatsurprisinglylowpowerlevels.ForsomedigitalmodessuchasJT65,100Woutputisconsideredobscene!

Butmostimportantly,adjustingforfullRFoutputignoresthefactthatyoumaybegrosslyoverdrivingyourradiotoachieveyoursatisfaction.Theresultisoftenawildlydistortedsignalthat’snotonlydifficulttodecode, itsplattersacross theband, ruiningeveryconversation in itswake.ThehamwhoinsistsongeneratingahideoussignalforthesakeofafewextrawattsisknownintraditionalparlanceasaLID.(No,itisn’tatermofendearment.)

RatherthangazingatthetransceivermeterasitdisplaysyourRFoutput,switchthemetertomonitorALC(AutomaticLimitingControl)instead.AlltransceiversdisplayALCactivitydifferently.Thedisplay

maysimplyindicatethepresenceandamountoftransmitaudiolimitingtakingplace.Otherdisplaysmayincludea“safezone.” If theALCactivity remainswithin the safezone,your transmitaudio levelsareacceptable.

Whenyoutransmitatestsignal,donotincreasetheaudiolevelbeyondtheALCsafezone,orbeyondthepointwhereALCactivityisexcessive.WhenyouseetheneedleorLEDsswinghardtotheright,thisisawarningthatyouaresupplyingwaytoomuchaudiototheradioandthattheALCcircuitistryingtoreinyouin.ThegoalistogeneratethedesiredRFoutputwhilekeepingALCactivitytoaminimum(orevenzero),

orwhilekeepingtheALCmeterinthesafezone.ItisimportanttokeepinmindthatminimalALCactivitydoesnotnecessarilyguaranteeacleansignal.Itdoesinmanyinstances,butyourbestinsuranceistoaskfor reportswheneveryouare indoubt. If someone reports thatyouare splattering, reduce the transmitaudioleveluntiltheysayyoursignalisclean.Notethissettingsothatyoucanreturntoitagaineasily.

ComputerSoundsWhenyoubeginlisteningtoHFdigitalsignals,don’tbesurprisedifyouoccasionallyhearbeep,dings,

chimesoradisembodiedvoicedeclaring,“You’vegotmail!”Most of this interference isn’t deliberate. It is caused byVOX-type interfaces that key transceivers

whenevertheydetectaudio–anyaudio–fromthecomputers.I’mwillingtobettheoperatorsaren’tevenawarethattheircomputersareguiltyofthisobnoxiousbehavior.Thesolution,atleastinWindows,issimple:Turnoff“Windowssounds”beforeyougetontheair.You

canalsodothismanuallybyopeningWindows’CONTROLPANELanddouble-clickingtheSOUNDandAUDIO DEVICES icon. Click the Sound tab and under SOUND SCHEMES select NO SOUNDS.(DependingontheWindowsversioninquestion,thelabelsmaydiffer.)Yourfellowhamswillthankyou!

CATCommunicationIfyoursoftwareandinterfacesupportfulltransceivercontrol(CAT),you’llneedtomakesurethatthe

data communication rates between the interface or computer and the transceiver are the same. Someclever pieces of CAT software will automatically analyze the data from the transceiver and quicklydeterminethedatarate.Forothers,you’llhavetoenteramenuandspecifythedatarate.

InmostCAT-capableradiosyou’llfindamenusettingthatwillallowyoutospecifyadatarate,oftenexpressedas“baud.”Arateof9600baud,forexample,iscommon.Youmayneedtoaccessthismenutofind out what setting the radio is currently using, or to change the radio’s data rate to something theinterfaceorsoftwarecanhandle.

WhenanInterfaceIsn’tanInterface—PACTORThroughoutthischapterwe’veheldfasttoanoverarchingassumption:thatthemodeyouwillchooseto

operatewillusesoftwarethat transmitsandreceivesthroughasounddevice.Thesounddevicecanbeinsidethecomputerorwithintheinterface.Eitherway,itisattheheartofyourabilitytocommunicate.

SamplingRatesandWindowsAllsounddevicesoperatebytakinganalogsignalsandchoppingthemintodigitaldata.Theydothisbysamplingthesignalatavery

fastrate,takingakindofdigitalsnapshotofthesignalcharacteristicsataparticularmomentintime.ThesamplingrateismeasuredinHertz(Hz).

MostHFdigitalprogramsrelyonasounddevicesamplingrateof11,025Hz.However,someWindowscomputersfudgethesamplingratebyatinyamount.Youwouldn’tthinkthiswouldn’tcauseaproblem,andmostofthetimeitdoesn’t,butthereareothertimeswhenitbecomesaseriousissue.

Ifthiserroroccursonyourcomputer,itcanresultinyourtransmitaudiofrequencybeingoutofsyncwiththeapparentreceivefrequency.Whenoperatingdigitalmodes,thiscanmanifestitselfinseveraldifferentways.WithPSK31,otherstationsmaynotrespondwhenyouanswertheirCQ,ortheymayrespondbutsaythatyouareofffrequency.Itcanalsoresultinbothyouandthepersonthatyou’retalkingto“walking”acrossthebandaseachofyoucorrectsyourtuningaftereachtransmission.

ThegoodnewsisthatthisproblemcanbefixedbysimplychangingthesamplerateinyourHFdigitalprogramfrom11,025Hzto12,000Hz.Almosteveryprogramworthhavinghassomemeanstodothis;youmayjusthavetogodiggingthroughthemenus.

Thereisoneexceptiontothisassumption:PACTOR.

PACTORisadigitalmodeinventedbytwoGermanamateursin1991andithasbeenevolvingeversince.PACTORisuniquebecauseitiscapableof100%error-freecommunicationatglobaldistancesontheHFbands.ThismakesPACTORthehands-downfavoritewhenmessagesmustgetthrougherror-free.That’swhyPACTORisthemostwidelyuseddigitalmodeamongthosewhoparticipateontheHFsideoftheWinlinknetwork.We’lldiscussWinlinklaterinthisbook.

PACTORworksitsmagicbysendingdatainsmallchunksorframes.Thereceivingstationanalyzesthedata and keeps whatever has arrived without errors. It transmits a short burst back to the originatingstationand tells it to repeat the frame.With luck, thenext retransmissionof the framewillarrivewithmostof thedata intact,orwithat least enough intactdata that the receiving stationcanmixandmatchbetweenthe“new”and“old”framestocomeupwithacomplete100%error-freeframe.Allofthisback-and-forthtransmittingmakesacharacteristicchirp-chirp-chirpsoundontheair.Italso

requires a fast-switching transceiver and a lot of computational horsepower. To this date no one haswrittenacomputerprogramthatiscapableofdoingPACTORwithsounddevices.ThePACTORtimingparametersaretoostrictandcomputeroperatingsystemtimingtendstobetooloose.So,themanufacturershavepackageddedicatedmicroprocessorcircuitryintoastand-alonebox.This

box,oftencalledacontroller,hasthespeedandefficiencytomeettherequirementsforPACTOR.Itcandoothermodes aswell, such asPSK31andRTTY.Unlike adesktopor laptop computer, a controllerdoesn’t labor under the burden of an operating system and it isn’t required to fulfill a broad range ofsimultaneoustasks.Sounds like a simple, elegant solution, doesn’t it? It’s reasonable to askwhy anyonewould bother

usingsounddevicestoenjoydigitaloperatingwhenastand-alonecontrollercandothejob.Theansweriscost.ThenewestPACTORcontrollersretailatabout$1000+.Anddon’tforgetthatyou

stillneedacomputerandsoftwaretocommunicatewiththecontroller.With most sound-device software selling at a low cost or even zero cost, and with even high-end

interfaces selling at less than $400, the cost to become active in sound-device-based HF digital—assumingyoualreadyownacomputer—issubstantiallylessthanthecostofaPACTORcontroller.IfyoureallywantPACTORcapability,youmustpurchaseacontroller—notwowaysaboutit.Onthe

Winlinke-mailnetworkyoumaybeabletogetawaywithanolderPACTORIcontrollerthatyou’llfindsellingforafewhundreddollars,buttostepuptomodernPACTORIIyouwillmostdefinitelyneedthe$1000+unitsmanufacturedbySCSCorporationontheWebatwww.scs-ptc.com.TheSCSmodelPTCIIusbisagoodchoicebecauseitoffersawiderangeoffeaturesinacontroller

that plugs directly into your computer’s USB port. You can purchase a set of cables to connect thePTCIIusb to your transceiver (an additional $50). In addition to PACTOR II, this controller will doPSK31,RTTY,CW,SlowScanTV,packetradioandmore.Keep inmind that to be successfulwithPACTORyour transceivermust be able to switch between

transmitandreceiveinlessthan20milliseconds.Manyrigscandothis,butifyouareindoubt,checktheQSTmagazineProductReviews.IfyouareamemberoftheARRL,you’llhavefullaccesstotheProductReviewarchivesonlineatwww.arrl.org/product-review.

ChapterTwo

PSK31

TheShortScoopPSK31isthemostwidelyusedHFdigitaloperatingmodetoday.LikeCW,itschief

advantageisthatitssignalsareverynarrow(energyandspectrumefficient)anditcanbedecodedunderverypoorconditions.

WhensoundcardtechnologytookovertheamateurHFdigitalworldintheyear2000,PSK31wasthevanguardmode.Itwas thebrainchildofPeterMartinez,G3PLX.Hewantedtocreateamodethatwaseasy touseyetextremely robust in termsofweak-signalperformance.Another importantcriterionwasbandwidth.TheHF digital subbands are narrow and tend to become crowded in a hurry (particularlyduring contests). Peter wanted to design amode that would do all of its trickswithin a very narrowbandwidth.In early 1999 Peter unveiled the first PSK31 software forWindows. The program required only a

common16-bitsoundcardfunctioningastheanalog-to-digitalconverter(andviceversa).WiththelargenumberofhamsowningPCsequippedwithsoundcards,thepopularityofPSK31exploded.TodayPSK31istheundisputedkingofHFdigital.JustgotoanyofthePSK31“wateringholes”(see

Table2.1)suchas14.070MHzandyou’llhearitsdistinctivewarblingsignalatjustaboutanytimeofthedayornight.

WhatisPSK31?

First,let’sdissectthename.The“PSK”standsforPhaseShiftKeying,themodulationmethodthatisused to generate the signal; “31” is the bit rate. Technically speaking, the bit rate is really 31.25, but“PSK31.25”isn’tnearlyascatchy.ThinkofMorsecodeforamoment.Itisasimplebinarycodeexpressedbyshortsignalpulses(dits)

and longersignalpulses (dahs).Bycombiningstringsofditsanddahs,wecancommunicate theentireEnglish alphabet alongwith numbers and punctuation.Morse uses gaps of specific lengths to separate

individualcharactersandwords.Evenbeginnersquicklylearntorecognizethesegaps; theydon’tneedspecialsignalstotellthemthatonecharacterorwordhasendedandanotherisabouttobegin.PSK31transmitsitsbinarycodeinaninterestingway.Insteadofkeyingthesignalonandoff,PSK31

usesDigitalSignalProcessingtocreateanaudiosignalthatshiftsitsphaseangle180°insyncwiththe31.25bit-per-seconddatastream.InPeter’sscheme,a0bitinthedatastreamgeneratesaphaseshift,buta1doesnot.So,PSK31 softwareuses twophase angles (0°or “inphase” and180°out of phase) tocommunicate 1s and 0s.SeeFigure2.1. Because two phase angles are used to accomplish this, it isusuallyreferredtoasbinaryphase-shiftkeying,orBPSK(mostpeopleusetheterm“PSK31”asakindofcatch-alllabel).

IfyouapplyaBPSKaudiosignaltoanSSBtransceiver,youendupwithBPSKmodulatedRF.Atthisdata rate the resulting PSK31 RF signal is only 31.25 Hz wide, which is actually narrower than theaverageCWsignal.ConcentratingyourRFintoanarrowbandwidthdoeswondersforreception,asanyCWoperatorwill

tellyou.Butwhenyou’retryingtoreceiveaBPSK-modulatedsignal,itiseasiertorecognizethephasetransitions—evenwhen they are deep in the noise—if your computer knowswhen to expect them. Toaccomplishthis,thereceivingstationmustsynchronizewiththetransmittingstation.Oncetheyareinsync,thesoftwareatthereceivingstation“knows”whentolookfordatainthereceiver’saudiooutput.EveryPSK31transmissionbeginswithashort“idle”stringof0s.Thisallowsthereceivesoftwaretogetintosyncrightaway.InPSK31thephasetransitionsarealsomathematicallypredictable,somuchsothatthePSK31 software can quickly synchronize itself automaticallywhen you tune in during themiddle of atransmission,orafteryoumomentarilylosethesignal.Thecombinationofnarrowbandwidth,anefficientDSPalgorithmandsynchronizedsamplingcreatesa

modethatcanbereceivedatverylowsignallevels.Its terrific performance notwithstanding, PSK31 will not always provide 100% copy; it is as

vulnerable to interference as any digital mode. And there are times, during a geomagnetic storm, forexample, when ionospheric propagation will exhibit poor frequency stability.When you are trying toreceiveanarrow-bandwidth,phase-shiftingsignal,frequencystabilityisveryimportant.

TheFlavorsofPSK31

ManypeopleurgedPetertoaddsomeformoferrorcorrectiontoPSK31,butheinitiallyresistedtheideabecausemost error-correction schemes relyon transmitting redundantdatabits.Addingmorebitswhilestillmaintainingthedesiredthroughputrequiredadoublingofthedatarate.IfyoudoubletheBPSKdatarate, thebandwidthdoubles.Asthebandwidthincreases, thesignal-to-noiseratiodeterioratesandyougetmoreerrors.It’sastickydigitaldilemma.HowdoyouexpandtheinformationcapacityofaBPSKchannelwithoutsignificantlyincreasingitsbandwidth?Peter finally found theanswerbyaddinga secondBPSKcarrierat the transmitterwitha90° phase

differenceandaseconddemodulatoratthereceiver.Theresultisasignalthatconsistsoffourwaveformsthatdifferinphase,each90degreesapart.Petercallsthisquadraturepolarityreversedkeying,butitisbetterknownasquaternaryphase-shiftkeyingorQPSK.OperatingPSK31in theQPSKmodewillgiveyou100%copyundermostconditions,but there isa

catch.Tuning is twice as criticalwithQPSKas it iswithBPSK.Youhave to tune the receive signalwithinanaccuracyoflessthan4Hzforthedecodertodetectthephaseshiftsanddoitsjob.Obviously,bothstationsmustbeusingverystabletransceivers.ThereareotherformsofPSK31thatusehigherdatarates.Ofcourse,thehigherthespeed,thewider

thesignal.AsyouprowlthebandsyoumayoccasionallyheartheburrofPSK63,125oreven250.LikeQSPK, however, these modes are not common. Almost every warble you’ll hear on the air will beBPSK31.

DoestheSidebandMatter?WithBPSK,themostpopularPSK31modebyfar,theansweris“no.”Youcanhaveyourtransceiverinupperorlowersidebandand

workanysignalsthatappearinyoursoftwaredisplay.QPSKisanothermatter.SidebandselectioniscriticalforQPSK.MostQPSKoperatorschooseuppersideband,althoughlowersideband

wouldworkjustaswell.Thepointisthatbothstationsmustbeusingthesamesideband,whetherit’supperorlower.

SoftwareEvolutionandthePanoramicSolution

OneoftheearlybugaboosofPSK31hadtodowithtuning.MostPSK31programsrequiredyoutotuneyour radio carefully, preferably in 1-Hz increments. In the case of the original G3PLX software, forexample,thenarrowPSK31signalwouldappearasawhitetraceonathinwaterfalldisplay.Yourgoalwastobringthewhitetracedirectlyintothecenterofthedisplay,thentweakabitmoreuntilthephaseindicatorinthecircleabovethewaterfallwasmore-or-lessvertical(orintheshapeofaflashingcrossifyouweretuningatQPSKsignal).Regardlessofthesoftware,PSK31tuningrequiredpractice.Youhadtolearntorecognizethesightandsoundofyourtargetsignal.WiththeweakwarblingofPSK31,thatwasn’talwayseasytodo.Andifyourradiodidn’ttunein1-Hzincrements,thereceivingtaskbecameevenmoredifficult.NickFedoseev,UT2UZandSkipTeller,KH6TY,designedasolutionandcalleditDigiPan.The“pan”

inDigiPanstandsfor“panoramic.”WithDigiPantheideaistoeliminatetedioustuningbydetectinganddisplayingnotjustonesignal,butentiregroupsofsignals.IfyouareoperatingyourtransceiverinSSBwithoutusingnarrowIForaudio-frequencyfiltering,the

bandwidthof thereceiveaudio thatyou’redumping toyoursounddevicerangesfromabout100Hzto

3000Hz.Asyoumightimagine,withabandwidthofonly31Hz,manyPSK31signalscansqueezeintothat2900Hzchunkofspectrum.Panoramicsoftwareactslikeanaudiospectrumanalyzer,continuouslysweepingthroughthereceivedaudiospectrumandshowingyoutheresults inalargewaterfalldisplaythatcontinuouslyscrollsfromtoptobottom.Whatyouseeonyourmonitorareverticallinesofvariouscolorsthatindicateeverysignalthatthesoftwarecandetect.Brightlinesrepresentstrongsignalswhilefaintlinesindicateweakersignals.Other softwarewriters jumpedon thepanoramicbandwagonandsoonnearlyeveryPSK31program

usedwaterfalldisplaysofonetypeoranother.Thebeautyofpanoramicreceptionisthatyoudonothaveto tuneyour radio tomonitoranyof thesignalsyousee in thewaterfall.Yousimplymoveyourmousecursor to the signal of your choice and click. A cursor appears on the trace and the software beginsdisplaying text.You canhop fromone signal to another in less than a secondmerely by clickingyourmouse.

GettingontheAir–StepbyStep

Let’s take a step-by-step approach to your first PSK31 contact. To keep things simple, we’ll useDigiPansoftwareforWindowsasourexample.DigiPanisfreetodownloadandeasytounderstand.ItrunswellonWindowsXP,Vista,7and8.IfyouareaMacowner,I’drecommendyoustartwithW7AY’scocoaModem,whichisavailablefree

ofchargeatwww.w7ay.net/site/Applications/cocoaModem/.LinuxusersmaywanttostartwithFldigiatwww.w1hkj.com/download.html. Both are multimode programs that offer PSK31, but many of thesameideasyou’lllearnaboutDigiPanapplytomultimodesoftwareaswell,onlythelabelsandmenusmaychange.

Ifyou’dliketofollowalongwithyourcomputer,youcandownloadDigiPanfromwww.digipan.net,or from the specialGet on the Air with HFDigital page on the ARRLwebsite atwww.arrl.org/hf-digital.Note thatDigiPanwaswrittenbefore theadventofWindows7or8.As a result, theDigiPan“help”filesmaynotappearwhenyouclickontheHELPmenu.ItisaprogrammingquirkofVistaand7.Evenso,DigiPanissointuitiveyouprobablywon’tneedtoresorttoHELPasyouexplorethefeaturesthatextendbeyondthebasicswe’llcoverhere.

We’llbeginbyassumingthatyou’veinstalledDigiPanonyourharddrive.WhenyourunDigiPanforthefirsttime,itwillaskyoutofillinyourcallsign,nameandlocation(QTH).Goaheadanddoso.YoucanleavetheCWIDboxunchecked.Throughout this exercise I’ll also assume that you have your interface hooked up between your

computerandyourHFtransceiver.

ConfiguringtheSoundCardandSerialPortBeforewegetstarted,weneedtodiscussapotentiallyvexingodditythatcanoccurwithsomesound

devicedriver applications.A driver is a small piece of software that is dedicated to a specific task,typically“talking”tovariousdevicesinsideoroutsidethecomputer.Adriveractsastheliaisonbetweenthesoftwareandthedevicethesoftwareisattemptingtouse.Forexample,aprinterdriveristheliaisonbetweenawordprocessingprogramandtheprinterhardware.In an effort to provide more user convenience, some sound device drivers attempt to detect when

something(suchasamicrophone)hasbeenpluggedintotheaudioports.Intheory,thedriversshouldthenautomaticallyroutetheaudiosignalstothesoftwareaccordingly.Thisisafineconcept,butitcancauseheadachesforHFdigitalsoftwareusers.Thepainoccurswhen

youstartyourHFdigitalapplication(suchasDigiPan)andinstantlyreceiveanerrormessagetellingyouthatthe“Soundcardisinuseordoesnotexist.”Thishappensbecausethedriverisn’tallowingyourHFdigitalsoftwaretogainaccesstotheaudiodatafromthesounddevice.Fortunately,thesolutionissimple:plug in the audio cables from the interface, or plug in theUSBcable if the interface contains its ownsounddevice.ThedriverwillbesatisfiedandwillallowyourHFdigitalsoftwaretoaccessthesounddevice.

OnceyouhaveDigiPanupandrunning,clickCONFIGUREandthenclickSOUNDCARD.Inthelittlewindowthatappearsyouwant tomakesurethat thesounddeviceType iscorrect (eitheryour internalsoundcardorexternalsounddevice)andthatDigiPanisusingthecorrectaudioinputsandoutputs.Forexample,ifyouareconnectingthetransceiver’sreceiveaudiototheLINEINPUTofyourcomputersoundcard,makesurethattheLINEINPUThasbeenselected.Don’tworryabouttheSampleratewindow.In theDigiPanCONFIGUREmenu, clickSERIALPORT.Here iswhere you’ll select the computer

portyouwilluseforPushtoTalk(PTT)tokeythetransceiver.HighlighttheCOMportyourinterfaceisusing.Remember that if you have an interfacewith aUSB cable, or if you are using aUSB-to-serialadapter,youneedtoselectthe“virtualCOMport”number.Re-readChapter1ifyou’veforgotten.Also,checktheboxeslabeledRTSASPTTandDTRASPTT.Bydoingsoyou’retellingDigiPanto

sendkeyingpulsesonboththeRequesttoSend(RTS)andDataTerminalReady(DTR)linesontheCOMport.YourinterfacewillbelookingforthePTTkeyingsignalfromoneoftheselines;bycheckingbothboxesyou’llcoverallyourbases,sotospeak.

Therearemanyother featuresyoucanconfigure inDigiPan tocustomize it toyour liking,but thesewillbesufficienttogetyoustarted.

ReceivingPSK31Turn on your transceiver, select Upper Sideband (USB) and tune to one of the PSK31 frequencies

showninTable2.1.Duringdaylighthours,14.070MHzisagoodchoice.Ifpropagationconditionsarefavorable,youshouldhearthewarblingsoundsofPSK31signals.

Lookatthewaterfalldisplay(thebottomwindow)inDigiPan.Ifeverythingisworkingproperly,youshouldseeascreensimilartoFigure2.2.Eachlinerepresentsasignal.Ifyourwaterfalldisplayisshowingonlyfaintbluelinesornothingatall, thismeansthatnotenough

receive audio is getting to the sound device in your interface or computer. If thewaterfallwindow isutterlyblack,thefirstthingstocheckareyouraudiocables.Makesuretheyarepluggedintothecorrectports.

Ifyouareusinganinterfacethathasreceiveandtransmitaudiocontrolsonthefrontpanel,makesurethereceiveaudiocontrolisturnedup.Ifyourinterfacelacksaudiocontrols,itistimetolookatthesoundcontrolsinyourcomputer.You can access the sound input level controls inDigiPan by clicking on the CONFIGURE menu,

followed by WATERFALL DRIVE. However, this function only works if your computer is runningWindowsXP.IfyouareusingWindowsVistaorWindows7,you’llneedtojumpthroughseveralhoops.FromyourWindowsStartmenu,opentheCONTROLPANELanddoubleclickontheSOUNDicon.Inthewindowthatopensnext,clicktheRECORDINGtab.Nowyou’llbepresentedwithalistofalltheaudioinputsanddevicesthatWindows“knowsabout.”

Theaudioinputorexternalsounddeviceshouldbehighlighted.Itmayalsoincludeacheckmark.If thecorrectinputordeviceisnothighlighted,clickonitnow.Withthedevicehighlighted,clickonthePROPERTIESbuttonandyou’llbepresentedwithyetanother

window.ClicktheLEVELStabandyou’llfinallyseetheslidercontrolthatwillallowyoutoincreasetheaudioinputlevel.Ifitisatminimum,turnitup(slideituportotheright).If all iswell, you should now see blue or yellow linesmoving from top to bottom in thewaterfall

window.Ifthewaterfallwindowisfilledwithayellowhazeandthesignallinesaremostlyred,youhavetoomuchaudio.Reducethereceiveaudioleveluntilonlythestrongestsignalsappearasyellowlines.Examinethewaterfallwindowclosely.Doyouseethenumbers1000,2000and3000alongthetopof

thewindow?Theseareaudio frequencies inHertz (Hz).Youmayalsonotice that thebluehaze in thewaterfallissomewhatbrighteratthefarleftandthatitfadestoblackatthefarright,probablyjustbeyondthe3000Hzmarker.Whatyouareseeingistheentireaudiobandwidthofyourradio’sreceiver,rangingfrom100toabout

3000Hz.Thewaterfall haze is brighter at the lower end because the audio response of your radio isstronger there. If youowna transceiver that allowsyou to adjust receiver audio equalization, you cantweakitforamoreuniformresponsefromlowtohighfrequencies,althoughthisisn’treallynecessaryforusingDigiPan.

Ifyouwanttotrysomethingeducational,switchinanarrowtransceiverIFfilter(suchasaCWfilter)whilewatchingthewaterfalldisplay.YoumaybeabletodothisbysimplyswitchingyourradiototheCWmode.You’llseethewaterfallhazesuddenlybecomemuchnarroweraccordingtothewidthofthefilter.You’ll alsonotice that all theother signalsoutside the filterbandwidthhavevanished.This is apowerfulillustrationofhowbeneficialanarrowIFfiltercanbe.

SwitchbacktoUSBandclickyourmousecursorononeofthesignallines.Youshouldberewardedwith text flowingacross the topwindow.To tune toadifferentsignal,allyouhave todo isclickyourmousecursoronanotherline.Itisimportanttoemphasizeherethatyouarenottuningyourradioasyouhopfromonesignaltothe

next.Yourradio’sVFOdisplayremainsfixedat14.070MHz.That’s themagicofpanoramicreceptionwithinanaudiobandwidth.Becauseapanoramicdisplayfreesyoufromtheneedtotuneyourradio,itisprobablyagood idea to lockyourVFOifyour radioprovides thatoption.Thiswillpreventyoufrom

accidentallybumpingtheknobandsiftingfrequency.Ifyouhaveseveralvisiblesignalsinthewaterfallwindow,hereissomethingfuntotry.DigiPanoffers

auniquemultichannelviewthatyoucanactivateintheVIEWmenu.Whenthisfeatureisactive,DigiPanwill attempt to simultaneously decode every signal in the waterfall! This makes for a fascinating, ifsomewhatchaotic,display.Using thewaterfall display youmay often see (and copy) PSK31 signals that you cannot otherwise

hear.It isnotatalluncommontoseeseveralstrongsignals(theaudibleones) interspersedwithwispyblueghostsofveryweak“silent”signals.Clickonafewoftheseghostsandyoumayberewardedwithtext(noterror-free,butgoodenoughtounderstandwhatisbeingdiscussed).Inthelowerrightcornerofthewaterfallwindowyou’llnoticegreenormulticoloredlinesthatseemto

move rapidly.This is thephasedisplay.Whenyouclickona strongBPSKsignal,you’ll see the linesturninggreenandaligningvertically(moreorless).ThisisanindicatorofhowwellDigiPanisdecodingthebinaryphaseshifts,soyoucanconsiderthedisplayasanindicatorofsignalquality.WithaperfectBPSKsignal thegreen lineswillbeperfectlyvertical.Ofcourse,perfectconditionsareuncommonsoyou’llusuallyseethegreenlinesflickeringallovertheplace.Ifthesignalisterribleorveryweak,thelineswillbeanythingbutvertical!

Youdon’tneedtopayattentiontothephasedisplayduringnormaloperation,but itcanoccasionallytellyousomeinterestingthings.Asanexample,let’ssaythatyou’veclickedyourmousecursoronwhatseemstobeastrongsignal,buttheresultingprintisgarbledatbest.Glanceatthephasedisplay.Ifthelinesareflickeringchaoticallyaroundthecircle,thismeansthatwhilethesignalmaybestrong,thephaserelationshipsarebadlydisrupted.ThiscanoccurwhenreceivingsignalsthathavecometoyoufromovertheEarth’spolesandaresufferingfrom“polarflutter.”You’llseethesamethingwhenreceivingPSK31from nearby stationswhose signals are arriving at your antenna along several different pathways andpartiallycancelingeachotherout(“multipathdistortion”).

TimetoTuneNowthatyou’vespentsometimedecodingPSK31conversations,nodoubtyou’llbeeagertotransmit.

Look at thewaterfall display and try to find an open spot between the signal lines.Click yourmousecursorononeofthoseemptyspaces.You’vejustchosenyourtransmitfrequency.Whenyoutransmit,thePSK31softwaregeneratesatonethatcorrespondstothefrequency“position”

inthewaterfallwhereyouclickedyourmousecursor.(Again,seetheaudiofrequencyscalealongthetop

oftheDigiPanwaterfalldisplay.)Whenthattoneisappliedtoyourradio,itcreatesanRFsignalonthecorrect frequency–acertainnumberofHertzaboveorbelow thesuppressedcarrier frequency. In theCONFIGURATION window you can set up DigiPan to display either the tone frequencies or thecorrespondingRFfrequenciesinthewaterfall.ItisworthwhiletonotethatthefrequencyyourtransceiverdisplaysintheSSBmodeisthesuppressed

carrierfrequency.Ifyou’veselecteduppersidebandonyourradio(USB),yourreceiveaudiorangeiseverythingfromthesuppressedcarrierfrequencytoabout2or3kHzaboveit.That’swhatyouareseeinginthewaterfalldisplay.DigiPaniscontinuouslysweepingthroughthisrangeanddisplayingtheresults.Ifyouselectlowersideband(LSB),yourreceiverrangeextends2or3kHzbelow thesuppressedcarrierfrequency.We’lldiscussthisinmoredetaillater.Let’s check your audio andRFoutput levels beforewe do anything else. Switch your transceiver’s

metertoALC.NowclicktheMODEbuttonalongthetopoftheDigiPanwindowandselectTUNE.Youtransceivershouldjumptothetransmitmodeandstaythere.Usingyourinterfacecontrolsoryour

audiooutputcontrolinWindows(thismayappearasatinyspeakericoninthelowerrightcorneroftheWindowsdesktop), increase theaudio leveluntilyou just seeALCactivity, then reduce the leveluntilALCactivityceases.IfyourtransceivermeterusesanALC“zone”instead,increasetheaudioleveluntiltheneedlemovestothehigherendofthezone.NowquicklyswitchthemetertodisplayRFoutputpower.YoushouldseefullRFoutputaccordingto

thepowerlevelyou’vesetontransceiver:100W,50Worwhatever.ClickOKintheTUNEwindowtounkeyyourtransceiver.ItispossiblethatyoumayseelessRFoutputthanyouanticipated.Thiscanbecausedbythewaythe

ALCfunctionworks inyourparticular radio;evenminimalALCactivitymay result in reducedoutput.Anotherpossibilityinvolvesthetransmitaudioresponseofyourradio.Abriefexplanationisinorder.

TransmitAudioResponse

Let’ssayyou’vechosenatransmit“location”intheDigiPanwaterfalldisplaythatcorrespondstoanaudio toneof1000Hz.Whenyoutransmit,yoursounddevicewillsenda1000Hztone toyourradio.SinceyouareoperatinginUpperSideband(USB),yourradiowillgenerateanRFsignal1000Hzabovethe suppressedcarrier frequencyshownon the transceiver’sdisplay. If thedisplay reads14.070MHz,youwillbetransmittingat14.071MHz(14.070+1000=14.071MHz).SeeFigure2.3.

Ifyouselectapoint inthewaterfall thatcorrespondsto300Hz,yourradiowill transmitat14.0703MHz(14.070+300=14.0703MHz).Sofarsogood.You’dthinkthatyourRFoutputlevelwouldbethesameregardlessofwhetheryousenta1000Hzor

300Hztonetotheradio,butyou’dbewrong.ThetransceiverhasaresponsecurvethatlimitsthedegreetowhichthevariousaudiofrequenciesareamplifiedbeforetheyareconvertedtoRF.Itappliestoaudiocoming inat theaccessoryportormicrophone jack.This responsecurvecandiffer fromonebrandofradiotoanother.Insomeradiositcanbechangedthroughafeatureoftenreferredtoas“transmitaudioequalization.”Generally speaking, the response tends to roll off at the high and low ends of the audio range. See

Figure2.4.WhatthismeanstoyouisthatthestrengthofanaudiotoneattheloworhighendsofthecurvewillbereducedwithinthetransceiverbeforeitbecomesRF.TheresultwillbereducedRFoutputeventhoughtheaudiolevelfromyoursounddevicehasn’tchanged.

Whatcanyoudo?Thereareacoupleofoptions…•Adjustyoursounddeviceoutputleveltocompensate.•Findanopentransmitfrequencythatisclosertothemiddleportionofthewaterfall(around1000Hz).

Ifyouencounterthisbehaviorwhenyoufindaninterestingstationwhosesignalisattheextremeedgeofthewaterfall(highorlow),anotherapproachistogentlyadjustyourtransceiverVFOwhilewatchingthewaterfalland“move”thesignalclosertothemiddleofthedisplay.Of course, the final option is to simply ignore the issue. PSK31 doesn’t requiremuchRF towork

successfully,soreducedoutputprobablywon’tmakethatmuchdifference.

CallingCQTherearetwowaystocallCQinDigiPan.Onemethod,theonewe’lldiscusshere,isbestdescribed

asthe“manualmethod.”Thereisamoreautomatedapproachthatwewilladdresslater.For now, click yourmouse cursor in themiddlewindowofDigiPan. This is your transmit buffer.

Everything you type in this window will be sent when it is time to transmit. Type the following,substitutingyourcallsignformine,ofcourse…CQCQCQCQWB8IMYWB8IMYWB8IMYCQCQCQCQWB8IMYWB8IMYWB8IMYCQKNowclicktheT/RbuttonintheDigiPan toolbar.Yourradioshouldpopintothetransmitmodeand

beginsendingyourCQmessage.You’llseeyourwaveringRFoutputandyouwillalsoseethetransmittedtextintheupperreceivewindow.Watchthistextclosely.Whenyouseethe“K”appear(“over”inMorsecode),quicklyclicktheT/Rbuttonagaintoplaceyourradiobackinthereceivemode.Nowwewait!Withlucksomeonewillrespond…

WB8IMYWB8IMYDEWJ1BWJ1BWJ1BKFromthispointtheconversationproceedsinturns.Youtypeyourreplyinthetransmitbufferandclick

T/Rtosendthetext,andthenwaitforhisresponse.WJ1B DEWB8IMY... Thank you for the reply. Name is Steve Steve and I am in WallingfordWallingford,CT.YourRSTis589.Howcopy?WJ1BDEWB8IMYKDigiPan, like most HF digital programs, allows you to type in the transmit buffer while you are

receiving.Thisisaveryhandyfunction–especiallyifyouareaslowtypist.Astheotherstationtransmitsyoucanreadhistextandtypecommentsinyourtransmitbufferasyougo.Whenitisyourturn,justclickontheT/Rbuttonandeverythingyou’vetypedwillbetransmitted.Athisendyou’lllookliketheworld’sfastest,smoothesttypist!

Macros

So farwe’ve discussed themanualmethodof sendingPSK31 textwithDigiPan.Now it is time tointroduceabitofautomationwithmacros.Theword“macro”isfromtheGreekμαkpófor“big”or“far.”Inthedigitalworldamacroisasingle

instructionthatcausesanentiresetofactions(orinstructions)totakeplace.ForHFdigitalsoftware,amacroisusedtosendpreformatted“canned”text.Macrosarecommonlyusedduringcontestswhenyouaretaskedwithsendingthesametextrepeatedly.

DXstationsalsousemacrostosendexchangesautomaticallywhentheyneedtoworkasmanystationsaspossible, asquickly aspossible.Hams inother countrieswill often relyonmacroswhen they arenotfluent in English. They prepare several textmessages asmacros so that they can send understandableEnglishquicklyandaccurately.Amacrocanbeassimpleorcomplexasyoudesire.DigiPancomeswithseveralmacrospreformatted.

Theseappearasbuttonsnearthetopofthewindow.Withyourmouse, rightclick on theCQ button.Awindowwill open to show you the preformatted

macro(seeFigure2.5).Thetextthatappearsinsidethe“lessthan”and“greaterthan”symbols(<and>)isinterpretedbyDigiPanasacommand,notastexttobesent.

<TX>CQCQCQDE<MYCALL><MYCALL><MYCALL>pseK<RXANDCLEAR>Strangeasitmaylook,thisisastraightforwardmacro.Let’sbreakitdown…

<TX>Thisisacommandtoplacetheradiointhetransmitmode.CQCQCQDEThisisplaintexttobesent.<MYCALL>Thisisacommendtoinsertyourcallsign.Itrepeatsthreetimes.

PseKMoreplaintext

<RXANDCLEAR> Thisisacommandtoreturntheradiotothereceivemodeandclear(erase)thetransmittedtextfromthetransmitbuffersothatitwon’taccidentallybesentagain.

As you can probably see, the T/R button is also amacro.When you click on it, theTXTOGGLEcommandexecutes.Thisplaces the radio into transmitmodeand thenwaits foryou toclick thebuttonagaintoreturntothereceivemode.Ifyourightclickononeofthemacrobuttonsagainandbrowsethescrollinglistofcommandsalongthe

right-hand side of the window, you’ll quickly realize that you can create some incredibly elaborate

macros.Contestmacros,forexample,canautomaticallysendtheotherstation’scallsign,asignalreportandaserialnumberthatincrementsbyonewitheverycontact–allwithasingleclickofyourmouse.Becarefulaboutrelyingtoomuchonmacros.Theyareconvenient–especiallytheCQmacro–butthey

canalsocauseconfusion ifused improperly. Inaddition,somehamscreatemacros thatcontain lengthydescriptionsoftheirstationequipment,families,etc.It’stemptingtotapthatmacrokeyandsitbackwhileyourcomputersendsmoreinformationthantheotherpersonreallywantstoknow!Finally,manyamateurscomplain–andwithsomejustification–thatoverrelianceonmacrostakesthe

pleasureoutofmakingcontacts.Acontactbasedonmacrosislittlemorethanabriefexchangeofcannedtext.Ahamwho isexpectinga leisurelychatwillbegravelydisappointed ifallyoudo is senda fewmacrosinstead.

ChapterThree

RTTY

TheShortScoopRadioteletypeisanolddigitalmode,butstillverypopulartoday,especiallyfor

contestingandDXing.

Radioteletype,betterknownasRTTY,isthe“oldman”oftheHFdigitalmodes.Despitemorethansixdecadesofamateuruseit isstill thetopmodeforHFdigitalcontesting.ItalsoremainsthekingofHFdigitalDXpeditions.Thereareseveralreasonsforthis…•Sheermomentum.RTTYhas a rich, longhistoryanda largenumberofHFdigitaloperatorshave

growncomfortablewithitovertheyears.LikeCW,RTTYhasaveneratedplaceinAmateurRadiolore.•RTTY-friendlytransceivers.HFtransceivershavebeendesignedwithRTTYinmindfordecades.As

youmay recall from Chapter 1, a substantial number of RTTY operators still prefer to use FSK andtransceivermanufacturerscontinuetomakethismodeavailableintheirdesigns.(Ifyoudon’tknowthemeaningofFSK,andwhyitisparticularlyrelevanttoRTTY,reviewChapter1.)•Performance.SeveralHFdigitalmodesaresuperiortoRTTYwhenitcomestospectrumefficiency

andweak-signal performance, butRTTYstill has an aceup its sleeve. In crowded conditions such ascontestsandDXpileups,RTTYcanoftenbedecodedwhenothermodescannot.PSK31,forexample,hasa “capture effect” where only the stronger of two signals on the same frequency can be decoded. Incontrast,RTTYiscapableofcomingupwithapartialprintoftwosignalsastheybattleitoutonthesamefrequency,dependingon their relativestrengths.This is importantwhenyou’reacontestorDXstationandseveralRTTYoperatorsarecallingyouatonce.•Speed.CoupledwithitsabilitytotoleratecrowdedconditionsisRTTY’s60word-per-minutespeed.

That’saboutasfastasmanyofuscantype,soitismorethanadequate.Otherdigitalmodesofferbetterweak-signalperformance,buttheyoftenincludeaspeedpenalty.NotsoforRTTY.RTTYisveryeasytouseandeverymultimodedigitalsoftwarepackagelistedinChapter1includes

RTTY in its collection.Also, there is a free, high-performanceRTTY program known asMMTTY byMakotoMori,JE3HHT.InthischapterI’llguideyouthroughaRTTYcontactusingMMTTY.Beforewegetstarted,however,let’sspendsometimebecomingfamiliarwithafewimportantRTTY

terms.

Mark,Space,ShiftandBaud

RTTYusesanolddigitalcodeknownasBaudot.EachBaudotcharacteriscomposedof5bits.That’senough to send every letter in the English alphabet, plus the number 0 through 9 and some limitedpunctuation.

InamateurRTTYcommunicationa“1”bit is representedbya2125-Hz toneand this isknownasamarksignal.A“0”bitisrepresentedbya2295-Hztonecalledaspacesignal.Thereisalsoastartpulseatthebeginningofthebitstringandastoppulseattheend(seeFigure3.1).TherapidswitchingbetweenmarkandspacetonesgivesRTTYitsdistinctivedeedle-deedlesound.WhenyouseeaRTTYsignalinawaterfalldisplay,youcaninstantlyspotthetwinparallellinesrepresentingthemarkandspacesignals.SeeFigure3.2.

AsyouexamineFigure3.2,you’llnoticethatthesignallinesareseparatedbyan“empty”area.Thisseparationisn’trandom.Infact,itishighlyprecise.Grabyourcalculatoranddoabitofsubtraction:

2295Hz–2125Hz=170Hz

Intheanswershownabove,170Hzisthedifferenceorshiftbetweenthemarkandspacefrequencies.TheAmateurRadioRTTYstandardistousea170-Hzshift.MaintainingpropershiftiscriticaltoRTTYcommunication. RTTY software that’s configured for a 170 Hz shift creates narrow DSP filters that“expect”thisexactfrequencyseparation.ARTTYsignalthat’susingadifferentshiftwillfalloutsidethefilters andwill be undecodable. FCC rules limit amateurRTTY to a 1 kHzmaximum shift, but you’llrarelyencounteranythingotherthana170Hzshift.You’llalsohearoccasionalreferencestoaRTTYsignalbeing“inverted.”Whenthisoccurs,themark

and space tone frequencies are swapped. As long as the station you are communicating with is alsoinverted, this isn’t a problem. However, it will render your text as gibberish to all the other RTTYoperatorswhoare“rightsideup.”Whenitcomestothesignalingrate(or“speed,”ifyouwill),thevastmajorityofRTTYyou’llhearon

theairwillbeperkingalongatarateof45baud(60wordsperminute).Thatsaid,youwilloccasionallyruninto75baudRTTY.

OntheAirwithRTTY–StepbyStep

If you don’t already have a multimode program that offers RTTY, give MMTTY a try. You candownloaditfreeathttp://hamsoft.ca/pages/mmtty.php,orgrabitatthespecialGetontheAirwithHFDigital page on the ARRL website at www.arrl.org/arrl-store/HF-Digital. You will also need todownload EXTFSK, a small COM port driver program for use withMMTTY, which you’ll find athttp://hamsoft.ca/pages/mmtty/ext-fsk.php(scrolldowntothebottomofthepage),orattheGetontheAirwithHFDigitalpage.Important note: InstallMMTTY first. After installing MMTTY, extract the EXTFSK files to the

directorywhereMMTTYresides.AswedidwithPSK31inChapter2,let’suseMMTTYasanexampleandstepthroughsettingupthe

software.MMTTY issomewhatcomplexbecause itoffers theability to tweakmanyof itsperformanceparameters.Evenso,itsdefaultsettings–theonesalreadyineffectwhenyouinstallthesoftware–areperfectlyadequateforourpurposes.IfyouareusingdifferentRTTYsoftware,you’llfindthattheMMTTYRTTYconfigurationisquitesimilar.

MMTTYSetupStartbyclickingyourmousecursoronOPTION(O)alongthetopoftheMMTTYwindow.Nowclick

onSETUPMMTTY(O).ASetupwindowwillopenwithseventabsarrayedhorizontally.Allthesetweakablesettingsmaylook

intimidating,butwe’reonlyconcernedwithafew.

ClickontheSOUNDCARDtabatthefarright.You’llbepresentedwithalistofthesounddevicesthatWindowshasdetected.Justclickontheemptycirclesnexttothesounddeviceyouareusingforreceiveaudiofromyourradio(audioinputtothesounddevice)andtransmitaudio(audiooutput)goingtoyourradio.DonotclickOK(atleastnotyet).

ClickontheTXtab.Intheupperrightcornerofthiswindowyou’llseeanarealabeledPTT&FSK.Clickon the arrow in thePORTwindowandhighlightEXTFSK at the very bottomof the drop-downmenu.IfEXTFSKisnotshowingupinthePORTmenuthatmeansEXTFSKwasnotproperlyplacedinthesamedirectoryonyourcomputerasMMTTY.EXE.

AfterEXTFSKhasbeenselected,gototheMISCtabandselecteitherSOUND+COM-TXD(FSK)ifyouareusingyourtransceivermicrophoneoraccessoryjackasthetransmitaudioinput,orCOM-TXD(FSK) if you’ve set up your radio for “true” FSK keying as described in Chapter 1. If you are justdabblinginRTTYforthefirsttimeandyou’vealreadysetupyourstationforPSK31oroneoftheothersound-device-basedmodes,selectSOUND+COM-TXD(FSK).NowclickontheUSBPORTbuttontoopentheUSBPORTOPTIONwindow.SelectNORMALinthiswindowandclickOK.

GobacktotheTXtabandclicktheOKbutton.TheEXTFSKwindowwillappearseparatelyfromtheMMTTYwindow.Inthiswindow,youcanselectwhichCOMportyouwishtoconfigure.Onceagain,ifyouareusingyourtransceivermicrophoneoraccessoryjackasthetransmitaudioinput,selecteithertheRTSorDTRlinesothatEXTFSKcankeyyourtransceiver’sPTT(PushtoTalk)lineatthemicrophoneoraccessoryjack.

InmostcasesthecorrectchoicewillprobablybeDTR.Ontheotherhand, ifyouareusingFSKforRTTY,youmayneedtoselectTXD.Ifyou’reindoubt,consultyourinterfacemanual.Atworst,youmayneed to experiment until you find which keying line does the trick. The good news about setting upEXTFSKisthatyouonlyhavetodoitonce.TheEXTFSKwindowwillremainopenwhileyou’reusingMMTTY.Ifnecessary,justdragitofftothe

sideandoutoftheway.WhenyoucloseMMTTY,itwillcloseaswell;itwillre-appearwhenyouopenMMTTYagain.

SetUpYourTransceiverNowthatyou’vesetuptheimportantfunctionsofMMTTY,it’stimetobringyourradiointothepicture.

Whathappensnextdependsonyourtransceiverdesign.

Aswediscussed inChapter1, ifyour transceiverhasa“RTTY,”“Digital”or“Data”mode thiscanmeandifferentthingstodifferentmanufacturers.Itcouldbelittlemorethanameanstoselecttheincomingand outgoing audio pathways and possibly implement some useful filter options.On the other hand, itcouldbetrueFSKwheretheradioisexpectingdatapulses(notaudio)fromyourcomputerorinterface.You’llneedtoconsultyourtransceivermanualtobesure.Forthesakeofmovingforward,let’sassumethat yourDIGITALmode involves taking audio to and from your interface and software. Turn on thetransceiverandselectyour“Digital”modenow.

Ifyour radiodoesn’thavea“Digital”mode, selectLOWERSIDEBAND(LSB) instead.This is thestandard forAFSKRTTYwhenusingSSBtransceivers.SelectingUSBwill flipyourmark/space tonerelationshipsupsidedown.Asaresult,youwon’tbeabletodecodesignals,andotherstationswon’tbeabletodecodeyourtransmissions.Takeamomenttotestthetransmitter.Tuneyourradiotothemiddleofoneofthefrequencyrangesin

Table3.1andmakesurethefrequencyisclear.Ifnot,pickanother.Onceyouareinaclearspot,clickyourmousecursoronthered-labeledMMTTYTXbutton.Yourtransceivershouldswitchtothetransmitmode.

IfyouareusingAFSKRTTY,youneedtobecarefulaboutoverdrivingyourradiowithtransmitaudio.AswithPSK31,thiswillgenerateaterriblydistortedsignal.Whiletransmitting,switchyourtransceivermetertoALC.IfthemeterisshowingALCactivity,oriftheALCindicatorisswingingoutofthe“safe”zoneasdescribedinChapter1,reduceyour transmitaudio.Dependingonthetypeofmeteryourradiooffers,thereshouldbenoALCactivity,ortheneedleshouldneverleavethesafezone.IfyouareusingtrueFSK,you’resparedfromworryingaboutanyofthis.That’soneoftheconvenient

features of FSK! Your interface is sending data pulses to your transceiver and your transceiverautomaticallygeneratestheproperdistortion-freeRFoutput.ThisisagoodtimetoremindyouaboutRFoutputpower.RememberthatRTTYisa100%dutycycle

mode.Ifyourrigisdesignedtohandle100%dutycyclesignals,you’resafe.Otherwise,you’llneedtoreduceyourRFoutputbyasmuchas50%.Checkyourtransceivermanual.ClicktheTXOFFbuttontoreturntoreceive.

TuningandDecodingRTTYSignalsEveryRTTYdecoder,whetheritworksinsoftwareorhardware,incorporatesasetofmarkandspace

audiofilters.Youcanthinkofthesefiltersasdualwindowsthatonlyopenfortonesthatareatthecorrect

mark and space frequencies, and separated by the proper shift. Themark and space filtering circuitrydetects and decodes the tones into digital 1s and 0s, which is exactly what your computer needs toprovidetextonyourscreen.Themoresensitiveandselectiveyourmark/spacedetectors,thebetteryourRTTYperformance,especiallyasitinvolvesyourabilitytocopyweaksignalsthroughinterference.It’seasytounderstandwhytuningaRTTYsignal(andjustaboutanyotherdatasignal)issocritical—

andwhyagoodtuningindicatorisoneofyourbestHFdigitaltools.WheneveryoustumbleuponaRTTYsignal,youmustquicklytuneyourreceiveruntil itsmarkandspacetonesfallwithinthe“skirts”ofthefilters andaredetected. It’spossible todo thisbyearonceyoubecomeaccustomed to the soundof aproperlytunedRTTYtransmission,butfewofushavethenecessarypatience.Instead,werelyonvisualindicatorstoguideus.InMMTTY you have two default indicators in the upper right corner of the screen. The top section

displays the receive audio as a rapidly varying waveform. Just below this window is a grayscalewaterfalldisplay.AsyoucanseeinFigure3.3,aRTTYsignalappearsastwopeakedwaveformswhentunedproperly in theupperwindow.These are themark and space signals.Noticehow thepeaks arecenteredonthetwowhitetuninglines.Inthewaterfalldisplaythemarkandspacesignalsappearastwowhitetracesdirectlybeneaththetuninglines.

OneofthestrengthsofMMTTYisitsflexibilityandthatappliestothetuningindicatoraswell.IntheView(V)menuyoucanchoosetoactivatetheXYScope(seeFigure3.4).ThisisasoftwarevariationofwhatRTTYold timersused to call the “crossedbananas”display.You tune theRTTYsignaluntil theellipsescross.

UnlessthereisacontestoraDXpileupgoingon,findingRTTYontheairmayrequiresomepatience.TakeanotherlookatthefrequenciesinTable3.1.ThisiswhereyouaremostlikelytoencounterRTTYonanygivenday.Twentymeters is themostpopularband.Anotheroption is tomonitor aW1AWRTTYtransmission from ARRL Headquarters. You’ll find the W1AW bulletin schedule online atwww.arrl.org/digital-transmissions. Note that RTTY transmissions are referred to as “Baudot” in theW1AWschedule.Once you’ve found a signal, tune it in carefully and watch the text march across the large receive

window.MMTTY is sensitive software and it has a tendency to respond to random noise by printingequallyrandomcharactersinthereceivewindow.Ifthisannoysyou,activethesoftwaresquelchfunctionbyclickingyourmousecursorontheSQbutton.

Asyouwatchthesignal,noticehowtheconversationflowsjustlikeavoiceorCWragchew.

KF6IDEWB8IMY . . .YES, IHEARDFROMSAMJUSTYESTERDAY.HESAIDTHATHISTOWERPROJECTWASALMOSTFINISHED.KF6IDEWB8IMYKIfyouwanttocallCQ,theprocedureissimple.MMTTYhastwo“canned”CQmessages(knownas

macros) thatyoucan sendbyclickingoneither theCQ1orCQ2buttons.Youcan right clickon thesebuttonstochangethemacrostoyourliking.SeethediscussionofmacrosinChapter2.Alternatively,youcanmanuallytypeyourCQinthebottomtransmitbufferwindow.Whenyouclickthe

TXbutton,MMTTYwillsendeverythinginthetransmitbuffer.Fornow,let’strytheCQ1button.Clickonitandyou’llhearthedelightfulchatterofRTTYandseethe

followingonyourscreen(withyourcallsigninsteadofmine):

CQCQCQDEWB8IMYWB8IMYWB8IMYPSEK

NoticehowtheCQisshortandtothepoint.Didyoualsonoticethatitrepeatedthecallsignseveraltimes?Remember that RTTY lacks error detection. If youwant tomake certain that the other stationcopiedwhatyousent,ithelpstorepeatit.You’llseethisoftenincontestexchanges.Forexample:

N6ATQDEN1RL...UR549549.STATEISCTCT.DEN1RLK

On theotherhand, ifyouknow that theother station iscopyingyouwell, there isnoneed to repeatinformation.AnoptiontoinvestigateinyourRTTYsoftwareisUnshiftOnSpace(UOS).Thereisabenefittousing

UOSwhenreceiving.Twospecialcharacters,LTRSandFIGS,areusedbytheRTTYcodetoindicatetothe computer or processor whether the characters that follow will letters or figures (numbers andpunctuation). IfyouenableUOS,yoursoftwarewillexit theFIGSshiftassoonas there isaspace,soyourdisplaydoesnotprintoutgarbageifthesoftwaremissestheLTRSshiftcharacterbecauseofnoiseorinterference.InMMTTYUSOisthedefault.MMTTY has anAutomaticFrequencyControl (AFC) function thatwill attempt to track the received

signalasitdriftsduetopropagationconditionsorotherfactors.YoucandisablethisbyclickingontheAFCbutton.TheadjacentNETbuttonhasasimilareffectonyourtransmittedsignal.AFCandNETarebothhandyfunctions,buttheycancauseproblemswhennotusedcorrectly.Ifyou

areenjoyingacasualRTTYconversationonanuncrowdedband,youcanleaveAFCandNETon.Butifthebandiscrowded–duringaRTTYcontest,forexample–youmaybebetteroffturningbothfunctionsoff.ManyRTTY operators run very tight filters in crowded band conditions, some as narrow as 250Hz. If theAFCandNET are on,MMTTY could easily shift your signal outside the range of the otherstation’sfilters.Bythesametoken,youcouldbecallingCQwithanarrowIFfilterandwonderingwhynoonereplies!

ChasingRTTYDX

RTTYisstill themostwidelyusedmodeforHFdigitalDXing.Youcanwork100countriestoearnyourRTTYDXCenturyClub(DXCC)award,andevenclimbtheladdertothestratosphericheightsofRTTYDXCCHonorRoll.RTTYDXingiscompetitiveandhighlyrewarding.LikeanyotherformofDXing,thequestforRTTYDXdemandspatienceandskill.WhenaDXpedition

isontheairwithRTTYfromarareDXCCentity,yoursignalwillbeincompetitionwiththousandsofotherHFdigitaloperatorswhowanttoworkthestationasbadlyasyoudo.Sometimespureluckisthewinningfactor,butthereareseveraltricksofthetradethatyoucanusetotweaktheoddsinyourfavor.

Don’tCall…YetLet’s say that you’re tuning through the HF digital subbands one day and you stumble across a

screamingmassofRTTYsignals.OnyourcomputerscreenyouseethateveryoneseemstobefranticallycallingaDXstation.Thisisknownasapileup.Youcan’tactuallyheartheDXstationthathaseveryonesoexcited,butwhattheheck,you’llactivate

yourtransceiverandthrowyourcallsignintothefray,right?Wrong!NevertransmitevenamicrowattofRFuntilyoucancopytheDXstation.Tossingyourcallsignin

blindlyispointlessandwillonlyaddtothepandemonium.Instead,takeadeepbreathandwait.Whenthecallssubside,canyouseetextfromtheDXstationonyourscreen?Ifnot,thestationisprobablytooweakforyoutowork(don’tevenbother),orhemaybeworking“split.”Moreaboutthatinamoment.IfyoucancopytheDXstation,watchtheexchangecarefully.Ishecallingforcertainstationsonly?In

otherwords,ishesendinginstructionssuchas“NorthAmericaonly”?CallingindirectviolationoftheDXstation’sinstructionsisagoodwaytogetyourselfblack-listedinhislog.(NoQSLcardforyou—ever!)Doeshejustwantsignalreports,orisheinthemoodforbriefchats?MostDXstationssimplywant“599”andpossiblyyourlocation—period.Don’tgivethemmorethantheyareaskingfor.(ADXRTTYstationonarareislanddoesn’tcarewhatkindweatheryouareexperiencingatthemoment.)

WorkingtheSplit

WhenDXRTTYpileups threaten to spin out of control,manyDXoperatorswill resort toworkingsplit. In this case, “split”means split frequency.TheDXstationwill transmit onone frequencywhilelisteningforcallsonanotherfrequency(orrangeoffrequencies).AgoodDXoperatorwillannouncethefactthatheisworkingsplitwithalmosteveryexchange.That’s

whyit issoimportanttolistentoapileupbeforeyouthrowyourselfintothemiddle.IfyoutuneintoapileupandcannotheartheDXstation,tunebelowthepileupandseeifyoucopytheDXstationthere.Ifhissignalisstrongenough,heshouldn’tbehardtofindifheisworkingsplit.Hissignalwillseemtobebyitself,answeringcallsthatyoucannothear.Thisisamajorcluethatasplitoperationistakingplace.Watchforcopysuchas…

CQDXDEFOØAAA,UP10(Translation:Heislisteningup10kHz)

CQDXDEFOØAAA,14085-14090(Translation:Heislisteningbetween14085and14090kHz)

Whatever you do, never call a split DX operation on the station’s transmitting frequency. Yourscreenwillquicklyfillwithrudecommentsfromotherswhoarelistening.Instead,putyourtransceiverintothesplit-frequencymode(betterdragoutyourusermanualifyou’reunsurehowtodothis).SetyourradiotoreceiveontheDXstation’stransmittingfrequencyandtransmitonhislisteningfrequency.IftheDXstationislisteningthrougharangeoffrequencies,you’llneedtoselectaspotwhereyouthinkyou’llbeheard.Changeyourtransmitfrequencyifthisparticular“fishingspot”doesn’tseemtobeworking.

ShortandSweetWhenyou’vedoneyourlisteninghomeworkandyou’rereadyforbattle,byallmeansfireatwill.Wait

untiltheDXstationfinishesanexchange.He’llsignalthatheisreadyforanothercallbysending“QRZ?”orsomethingsimilar.Whenit’stimetotransmit,makeitshortandtothepoint,likethis…

WB8IMYWB8IMYWB8IMYK

Listenagain.Hasherespondedtoanyoneyet?Iftheansweris“no”andotherstationsarestillcalling,theDXisprobablytryingtosortoutthealphabetsoupofconfusiononhisscreen.Tryagain.

WB8IMYWB8IMYWB8IMYKK

Youmightmake it through at just the rightmomentwhen other signals subside briefly, orwhen theionospheregivesyouanunexpectedboost.Butifnooneiscalling,orifyouheartheDXstationcallingsomeone else, stop. You lost this round, so give the lucky winner his chance to be heard. Your nextopportunitywillbecomingupshortly.

DidHeCallYou?Watchyourscreencarefully.IftheDXstationonlycopiedafragmentofyourcallsign,hemightsend

somethinglike…

IMYIMYAGAIN??

In this instancehe copiedonly the last three lettersofmycall sign (“IMY”).Fadingand flutter canmakeRTTYsignalsdifficulttocopyclearly.Thebestthingtodoisreplyrightaway,sendingyourcall

signthreetimesjustlikebefore.Ifluckisonyourside,you’llsee…

WB8IMYDEFOØAAA...TNX.599.QSL?K

Andwithexcitedfingersyouanswer…

QSL.UR599.TNXAND73DEWB8IMYK

RTTYContesting

Nothingtestsyourequipmentandoperatingskillslikeacontest,andwhenitcomestodigitalcontestingRTTYisthe#1mode.SeethelistofmajorannualRTTYcontestsinTable3.2.

Acontestreallyshakesthebugsoutofyourstation.Ifyouhaveshortcomingsinyourantennasystem,you’regoingtodiscoverthemveryquickly.Ifyourtransceivercan’tseemtohandlethecrunchofdozensof signals inproximity, itwillbecomepainfullyapparentwithinminutes. Ifyouneedbetter loggingorcontestsoftware,thefirsthourofacontestwillprovideapowerfulmotivationtoupgrade.Somehamsshuncontestingbecausetheyassumetheydon’thavethetimeorhardwarenecessarytowin

—andtheyareprobablyright.Butwinningisnottheobjectiveformostcontesters.Youenteracontesttodothebestyoucan,topushyourselfandyourstationtowhateverlimitsyouwish.Thesatisfactionattheendofacontestcomesfromtheknowledgethatyouwerepartofthegloriousfrenzy,andthatyougaveityourbestshot.Contesting also has a practical benefit. If you’re an award chaser, you can work many desirable

stationsduringanactivecontest.DuringtheARRLRTTYRoundup,forexample,somehamshaveworkedenoughinternationalstationstoearnaRTTYDXCC.JumpintotheNorthAmericanRTTYQSOPartyandyoustandagoodchanceofearningyourWorkedAllStatesinasingleweekend.Always remember that contesting is ultimately about enjoyment. The thrill of the contest chase gets

yourheartpumping.Thelittletriumphs,likeworkingthatdistantstationeventhoughhewasdeepinthenoise,willbringsmilestoyourface.You’llmakeanumberoffriendsalongtheway,too.Whydoyouthinkitiscalledthe“brotherhoodof

contesting”?

DigitalContestingTipsforthe“LittlePistol”Ifyouarelikemostamateurs,yourstationfallsintotheLittlePistolcategory.Minedoes,too.TheLittle

Pistol stationusually includes a low- tomedium-priced100-W transceiver feeding anomnidirectionalantennasuchasadipole,vertical,end-fedwireandsoon.Evenifyouareblessedwithabeamantennaonatowerorrooftop,inalllikelihoodyouarestillaLittlePistol.AttheoppositeendofthespectrumaretheBigGunstations.Theyhavemultiplebeamsontalltowers,

phasedarrayantennasonthelowerbands,incrediblylongBeveragereceivingantennasandmore.Theyownhigh-end (read: expensive) transceivers thatboast razor-sharp selectivity, and theyusually couplethemto1.5kWlinearamplifiers.SohowdoesaLittlePistolgoaboutbeatingaBigGuninadigitalcontest?Withrareexceptions,he

can’t.BangingheadswithaBigGunstation isusuallyanexercise in futility.He isgoing tohearmorestations,andmorestationsaregoingtohearhim.Focus,instead,onusingyourwitsandequipmenttogetthebestscorepossible.Youprobablywon’tbeataBigGun,butyoucouldmakehimsweat!

CheckYourAntenna

Howlonghasitbeensinceyou’veinspectedyourantenna?Iseverythingcleanandtight?Andhaveyouconsideredtryingadifferentantenna?Contestsareterrifictestingenvironmentsforantennadesigns.Forexample,ifyou’vebeenusingadipoleforawhile,whynottryaloop?Justsetuptheantennatemporarilyforthedurationofthecontestandseewhathappens.

CheckYourEquipment

IfyouarehavingproblemswithRFgettingintoyourcomputerorsoundcard,fixtheseglitchesbeforeyoufindyourself inacontest.Also,considerspending$140orso to installa500-HzIF filter inyourradioifitdoesn’thaveonealready,orifitlacksbuilt-inIFDSPfiltering.Finally,checkyourcomputerand software. Make sure you understand the program completely. Set up any “canned”messages/responsesandtestthembeforethecontestbegins.

UnderstandPropagation

IfyouareparticipatinginaDXcontest,isitagoodideatoprowlthe40-meterbandinthemiddleofthe day? No, it isn’t. Forty meters is only good for DX contacts after sundown. If you are huntingEuropeansorAfricanson10or15meters,when is thebest time to lookfor them?Theanswer is latemorningtoearlyafternoon.Inotherwords,letpropagationconditionsguideyourconteststrategy.Yourgoalistosqueezethemost

outof everybandat the right timeofday.For example, Imight start theARRLRTTYRoundupon10metersandthenbouncebetween10,15and20metersuntilsunset.Aftersundown,I’llconcentrateon20and40meters.Inthelatenightandtheweehoursofthemorning,I’llprobablylimitmyselfto40and80meters.Insomecontestsyoucanenterasasingle-bandstation.Whichbandshouldyouchoose?Thatdepends

onthecontestandyourequipment.Ifyouhavea15-meterbeamandyouareenteringaDXRTTYcontest,itmakessensetoconcentrateon15meters,eventhoughyou’llprobablyfindyourselfwithnothingtodoin the late evening after the band shuts down.Twentymetersmakes sense as the ultimate “around theclock”band,butit isoftenverycrowdedduringcontestsandpopulatedwithBigGunstations.Insomeinstancesyoumayfinditmore“profitable”toconcentrateyoureffortsonanotherbandwithoutsomanysignals.

HuntingandPouncingvs.“Running”

ThecommonsenseruleofthumbisthataLittlePistolstationshouldonlyhuntandpounce.Thatmeansthatyoupatrolthebands,watchingfor“CQCONTEST”onyourmonitor,andpouncingonanysignalsyoufind.TheBigGuns,ontheotherhand,oftensetupshoponclearfrequenciesandstartblastingCQs.Ifconditionsarefavorable,they’llbehaulingincontactslikeacommercialfishingtrawler!Thisisknownasrunning.In many cases Little Pistols are probably wasting valuable time by attempting to run. There are

situations,however,whererunningdoesmakesense.Ifyou’vepouncedoneverysignalyoucanfindonaparticularband, trysendinganumberofCQsyourself tocatchsomeof theotherpouncers. Ifyousendfive CQs in a row and no one responds, don’t bother to continue.Move to another band and resumepouncing.

SeektheMultipliers

Everycontesthasmultipliers.TheseareUSstates,DXCCcountries,ARRLsections,gridsquaresandso on, depending on the rules of the contest. Amultiplier is valuable because itmultiplies your totalscore.Let’ssaythatDXCCcountriesaremultipliersforourhypotheticalcontest.You’veamassedatotalof

200pointssofar,andindoingsoyoumadecontactswith50differentDXCCcountries.200×50=10,000pointsThose50multipliersmadeahugedifferenceinyourscore!Imaginewhatthescorewouldhavebeenif

youhadonlyworked10multipliers?Ifgivenachoicebetweenchasingastationthatwon’tgivemeanewmultiplierandpursuingonethat

will,I’llspendmuchmoretimetryingtobagthenewmultiplier.

ContestSoftware

Noonesaysyouhavetousesoftwaretokeeptrackofyourcontestcontacts,butitcertainlymakeslifeeasier! One of the fundamental elements of any contest program is the ability to check for duplicatecontactsordupes.Workingthesamestationthatyoujustworkedanhouragoisnotonlyembarrassing,itisawasteoftime.Thebettercontestprogramsfeatureautomaticdupechecking.Whenyouenterthecallsignintheloggingwindow,thesoftwareinstantlychecksyourlogandwarnsyouifthecontactqualifiesasadupe.Themoresophisticatedprograms“know”therulesofallthepopulardigitalcontestsandtheycanquicklydeterminewhetheracontactistrulyadupeundertherulesofthecontestinquestion.Somecontests,forexample,allowyoutoworkstationsonlyonce,regardlessoftheband.Othercontestswillallowyoutoworkstationsonceperband.

A good software package will also help you track multipliers. It will display a list of multipliersyou’veworked,orshowtheonesyoustillneedtofind.AnyofthecontestsoftwarepackagesadvertisedinQSTandtheNationalContestJournal (NCJ)will

function well. To minimize headaches, however, my suggestion is to stick with software writtenspecificallyforcontesting.Therearetwopopularcontestingsoftwarepackagesonthemarkettoday:•N1MMLogger is apopular freecontestingapplication forWindows.Youcandownload the latest

versionathttp://n1mm.hamdocs.com/.N1MMLoggersupportsRTTYcontestingwithMMTTY.• WriteLog by Ron Stailey, K5DJ, is a full-featured Windows-based software package with an

interesting twist–abuilt-inRTTYprogram.LikeRTTY,WriteLog offers automaticdupe checkingandflagging,multiplierdisplays,radiocontrol,cannedmessagesandmore.SeetheWriteLogsiteontheWebatwww.writelog.com.

ChapterFour

JT65

TheShortScoopJT65isn’tamodeforconversation,butwhenitcomestomakingvalidcontactswithlow

powerandpoorantennas,JT65ishardtobeat.

“I’mhearinga strange signalon severalHFbands. It sounds like someonesending random tonesormusic.Itplaysslowlyforabout50seconds,stopsforawhile,andthenplaysagain.Whatisit?”At the time this book was written, this question was arriving in e-mail inboxes at the ARRL

Headquarters Regulatory Branch at a rate of about once per week. Some amateurs even send audiorecordingsofthesuspicioussignals.ChuckSkolaut,KØBOG,ourFieldandRegulatoryCorrespondent,alwayssmilesashelistenstotherecordingsbecauseheknowstheanswerbyheart:JT65.Bynowamateursareusedtothesoundsmostdigitalmodescreate.They’velearnedtorecognizethe

constant warbling tones of PSK31, the rhythmic pulses of PACTOR, the “scratchy” rumble ofHellschreiberorthemulti-tonemusicofRTTY,MFSK16,Oliviaandothers.But JT65 isunique. Itmarches, asThoreausaid, to thebeatofadifferentdrummer. Ifyou’venever

hearditbeforeitwillstopyoucold.AsyoutuneacrossaJT65signalyou’llheartonesofvaryingpitchthat“play”slowly,likesomeonelazilypeckingonanelectronickeyboard.Cryptic and strange as the tonesmay be, youmight be surprised to learn that they carry call signs,

signal reports and other bits of information. Evenmore surprising is the fact that information can beextractedfromaJT65signalevenwhenitisextremelyweak.

The“JT”inJT65

JT65debutedaspartoftheWSJTsoftwaresuitecreatedbyDrJoeTaylor,K1JT.AsaNobelPrize-winningscientistwhostudiespulsarsandotherdistantastronomicalobjects, Joehasakeen interest inweak signals. Joe’s software exploits the power ofmodern desktop and laptop computers to separateweaksignalsfromnoiseanddecodetheinformationtheycontain.Withjustasoundcardorsoundchipsetandatransceiverinterface,WSJTmakesitpossibleforhamswithmodeststationstoenjoyVHFmeteorscattercommunicationandevenmoonbounce,wheresignalsare literallybouncedoff thesurfaceof theMoon and returned to Earth. WSJT is available for free downloading athttp://physics.princeton.edu/pulsar/K1JT/Download.htm.Inthebeginning,JT65wasembracedbysomemembersofthemoonbouncecommunityanditwasan

instantsuccess.ThankstoJT65,amateurswithsinglelong-boomYagiantennasand150WofRFoutputcanexperiencethethrillofcommunicatingoverthelongest“LongPath”ofall.Butitwasn’tlongbeforesomeonewonderedwhatwouldhappenifJT65wasusedontheHFbands.

DigitalcommunicationonHFisn’tnearlyaschallengingasgettingasignaltotheMoonandback,soitstoodtoreasonthattherewouldbeplentyof“performancemargin”toprovidefascinatingresults.Tonoone’ssurprise,thisturnedouttobetrue.UsingavariantofJT65knownasJT65A,evenafewwattsofJT65modulatedRFtoawiredipoleantennaresultedintranscontinentalandevenglobalcommunication.

DedicatedJT65Software

JT65 is one of severalmodes in theWSJT package, available for free downloading on theweb athttp://physics.princeton.edu/pulsar/K1JT/Download.htm.However,JoeLarge,W6CQZ,thoughtmoreamateursmighttryJT65onHFifitwasavailableinsoftwarespecificallydesignedtomakeiteasiertoenjoy contacts. The resultwas his JT65-HF application forWindows and it soon proved Joe’s hunchcorrect.SinceJoe’ssoftwaremadeitsdebut,JT65activityontheHFbandshasincreasedsubstantially.MoreaboutJoe’samazingsoftwareinamoment.

SoWhatisJT65Anyway?

Theshortandsimplifiedanswertothisquestionis thatJT65isaweak-signaldigitalmodethatusesone-minutetransmit/receivesequences,meaningthatyoutransmitwithinaone-minutewindowandthenlistenforoneminute.TransmissionactuallybeginsonesecondafterthestartofaUTCminuteandstopsprecisely 47.7 seconds later. There is a 1270.5 Hz synchronizing tone and 64 other tones. ThiscombinationgivesJT65itsunusualmusicalquality.Tight time and frequency synchronization is critical to JT65. Your SSB transceiver needs to be

reasonablystable,althoughI’veyettoseeamoderncommercialradiothatistoo“drifty”forJT65.Driftycomputer time is a differentmatter, however.Windows PCs are notorious for sloppy timekeeping, buttherearewaystodealwiththis,asyou’llsee.JT65isnota“conversational”modelike,say,PSK31.Instead,theideaistoexchangejustthebasic

information required for a valid contact: call signs and signal reports. JT65-HF measures the actualreceivedsignalstrengthandincorporatesitintotheexchange.WhenyoureceiveareportduringaJT65-

HFexchange,you’llknowexactlyhowstrongyoursignalis(indB)attheotherend.JT65contactscountformanyawardssuchasWorkedAllStatesortheDXCenturyClub.Asidefrom

the fun of award chasing, it is amazing to seewho you can contact with JT65while usingminisculeamountsofpower.SomeJT65enthusiastsareusingoutputlevelsinthemilliwattrange.Infact,50Wisconsidered“highpower”intheJT65world.

JT65-HFSoftwareSetup–StepbyStep

JT65 is anAFSKmode inwhichyouapply transmit audio toyour transceiver, just likePSK31andother sound-device-basedmodes. Ifyou’ve setupyour stationaccordingly, asdescribed inChapter1,you’regoodtogo.MostamateurstryingJT65ontheHFbandsareusingW6CQZ’ssoftwareandIrecommendthatyoudo

the same. You can download the latest version at no charge from Joe’s SourceForge page athttp://sourceforge.net/projects/JT65-HF/files/.OryoucangetitfromthespecialGetOntheAirwithHFDigitalpageontheARRLWebatwww.arrl.org/HF-Digital.There isn’taversionofJT65-HF forMacorLinuxusers,butIhavemanagedtorunJT65-HFsuccessfullyunderLinuxusingWine.MacandLinux users may also be able to do the same by using a Windows emulator such as CrossOver(www.codeweavers.com).

BeforeyoustartJT65-HF,makesureyourinterfaceispluggedintoyourcomputer.JT65-HFisoneofthoseapplicationsthatneedsto“see”thattheaudioinputsandoutputsareproperlyinplacewhenitstartsoritwillgenerateacrypticerrormessage.WhenyoustartJT65-HFforthefirsttime,yourfirsttaskistosetuptheprogram.ClickonSETUPin

theupperleftcorner.ThiswillopentheCONFIGURATIONwindow.Thiswindowhasseventabslineduphorizontally,butweonlyneedtobeconcernedaboutafewofthem.

ThemostimportanttabisSTATIONSETUPanditshouldbevisibletoyouimmediately.Fillinyourcall sign and your grid square. If you don’t know your grid square, you can find out online by usingK2DSL’shandycalculatoratwww.levinecentral.com/ham/grid_square.php.AllyouhavetodoisenteryourZIPcodeandthesitewillrespondwithyourgridsquare.

SelectyourSOUNDINPUTandSOUNDOUTPUTdevices.Click thedrop-downarrowsandyou’llseealistofeverydeviceWindowsrecognizes.Ifyouareusingthesoundcardorsoundchipsetinyourcomputeritwillappearinthislist,probablywithalabelsuchas“Microphone”or“Speakers.”Ifyouareusinganinterfacewithabuilt-insounddevice,itmayappearwithanoddlabelsuchas“USBCodec.”I suggest that you accept the default settings for all the checkboxes that appear below this section,

particularly the one labeled ENABLE AUTOMATIC RX/TX SAMPLE RATE CORRECTION. Thishandyfeaturewillautomaticallyadjustyoursounddevicesampleratewhentheprogramstarts.Youmayseeevidenceofitsactivityinthefirstfewsecondsaslinesofthewaterfalldisplayappeartoskewtotheleftorrightbeforesettlingdowntoaperfectlyverticalorientation.NowclicktheRIGCONTROL/PTTtabandfillintheCOMportnumberforthelineyouareusingto

keyyour transceiverbetween transmit and receive.Youcan test this functionbyclickingon theTESTPTTbutton.Whenyoudo,yourtransceivershouldquicklybounceintothetransmitmodeandthenbacktoreceive.Belowthissection,you’llseearowlabeledHamRadioDeluxe,OmniRigandCommander.This is

onlyimportantifyouareusingoneofthesethreepiecesofsoftwaretocontrolyourtransceiver.Inmostinstancesyoucanignorethisrow.Next, click on the tab labeled HEARD LIST/RB STATISTICS. If your station has an Internet

connection,JT65-HFwillshareinformationaboutthestationsyouarehearingsothatotheramateurscanobserve propagation conditions or test their equipment. Sharing this information is harmless and veryhelpfultothehamcommunityatlarge.Lookatthereportsonhttp://pskreporter.info.I’dsuggestthatyoujointhepartybyfillinginyourcallsignandashortdescriptionofyourantennasystem.

Onthispageyou’llseearowlabeledOmniRig,HamRadioDeluxeandCommander.JT65-HFhastheabilitytoreadtheoperatingfrequencyfromyourradiothroughoneoftheseprograms.YoudonotneedthisfunctiontoenjoyJT65-HF; it ismoreofaconveniencefeature,asyou’llseelater.Ifyouareusingoneoftheseapplicationsforrigcontrol,goaheadandclick“enable”intheappropriatebox.Otherwise,leaveitalone.Alltheothertabsaresafetoignoreatthistime.TheirfunctionsallowyoutocustomizeJT65-HFandto

keep things simplewe’re going to stickwith all the default settings for now.ClickSAVE SETTINGSANDCLOSEWINDOW.

TheJT65-HFMainScreenLet’stakealookattheJT65-HFmainscreen,sectionbysection,startingatthetop.SeeFigure4.1.

ThewaterfalldisplaydominatesmostofthetopportionoftheJT65-HFmainscreen.WheneverJT65-HFisrunning,itsweepsthroughyourreceiveaudiospectrumfrom0to2000Hz.Everysignalitdetectsappearsinthiswindow.You’llnoticethatthewaterfallisdividedintotwohalvestotherightandleftofthecenter“zero”point.

Thedisplaymarkersarepositivetotherightofthezero(0to1000)andnegativetotheleftofthezero(0to-1000).Alongthetopofthewaterfallyou’llseearedbracket.Ifyouclickyourmousecursorwithinthewaterfalltheredbracketwillmovetothepositionyoujustclicked.Thebracketrepresentsyour200Hztransmit/receivewindow.JT65-HF can operate in simplex (transmitting and receiving on the same frequency) and split

(transmitting and receiving on different frequencies).Most of your contacts will be simplex, but it isworthwhile toknowthatJT65-HF has split-frequencycapability.Twobracketsappearwhenoperatingsplit–redforthetransmitfrequencyandgreenforthereceivefrequency.Ontheleftsideofthewaterfall,youhavetherightandleftchannelaudioinputcontrols.Whentheband

isquiet(whentherearenosignals),youshouldadjusttherightandleftchannelcontrolstoachieve0dBon both channels. Too much or too little audio makes it difficult to decode signals. As Goldilocksobservedinthechildren’stale,thebestporridgewastheonethatwasnottoohotandnottoocold–justright.Below thewaterfall you’ll see controls for color, brightness, contrast, speed and gain.You’re safe

leavingalltheseattheirdefaultsettings.Thereislittleneedtochangethemunlessyou’rehavingdifficultyviewingthewaterfall,orunlessyouarerunningJT65-HFonaslowcomputer.Moving to the lower right section we have a number of checkboxes and buttons. These may seem

confusingbuttheirfunctionswillbecomemoreapparentwhenwemakeourfirstcontacts.

MESSAGETOTXisthetextyouaresendingtotheotherstation.YoucansendtextmanuallyintheTXTEXTwindow,butyouare limited to13characters. Immediatelybelowthiswindowyousee the red-labeled TX GENERATED window. This window is for transmitted text that JT65-HF generatesautomatically, either when you click on one of the buttons below, orwhen you click on a line in thedecodingwindow.Again, the functionof thiswindowwillbecomeclearaswestep throughyour firstcontact.Totherightofthemessagewindowsarebuttonstoenableorhalttransmission.Belowthesebuttonsis

thesectionthatallowsyoutochoosewhetheryouwishto transmitonevenoroddminutes.Rememberthatwith JT65 you transmit and receive in turns – during oneminute you transmit and during anotherminuteyoureceive.Therefore,oneminutewillbeanodd-numberedminute(suchas2105UTC)andthenextminutewillbeaneven-numberedminute(suchas2106UTC).InmostinstancesJT65-HFwillmakethechoiceforyou.However,whencallingCQyougettochoose

whenyouwillbegintransmitting–onanevenoroddminute.Youdefinitelydon’tneedtoworryabouteven and oddminuteswhen you are answering someone else’s call. That station has already selectedwhichminute (even or odd) he will use.When you respond, JT65-HF will automatically choose theoppositeminute.Belowthetext-generatingbuttonsyou’llfindseveralotherinterestingsections.TheTXDFandRXDF

sectionsareforsplit-frequencyapplications.ForthevastmajorityofyourJT65contactsyouwillworksimplex,soyouwanttoleavetheTXDF=RXDFboxchecked.AnexceptiontotheruleiswhenyouarecallingCQ,whichwe’lladdresslater.Below the TX DF and RX DF sections you’ll find the controls for SINGLE DECODER BW

(Bandwidth) andMULTI DECODER SPACING. This is another set of controls you’ll rarely have areason to change from their default values.Normally you’d never disable themultiple-signal decoderunlessyouareusingaparticularlyslowcomputer.Thedefaultof100Hzforsinglebandwidthisusuallyadequate.PutacheckmarkintheAFC(AutomaticFrequencyControl)boxsothatJT65-HFcancompensatefor

stationsthatmaybedriftingabit.Ifyouliveinanareawithfrequentstormsorothersourcesofnoise,putacheckmarkintheNOISEBLANKboxaswell.ENABLEMULTIdecoderdoesexactlythat.Whenenabledthedecoderwillattempttofindanddecode

all possible JT65 signals within the 2 kHz passband. Unless you are using a slow computer that hasdifficultyprocessingsomuchinformationatonce,alwaysleavethisboxchecked.To the right you’ll find the LOGQSO button.When you click this button JT65-HF will save your

contact information (who you worked, when, etc) to the file jt65hf_log.adi that you can import intoanotherloggingprogram.UseWindowsExplorertosearchforjt65f_log.adionyourharddrive.Finally,at thebottomof thelowerrightportionof theJT65-HFwindowyou’ll find twocheckboxes

labeledENABLERBandENABLEPSKR,alongwithasizeablewindowlabeledDIALQRGKHZ.Ifyouareusingtransceiver-controlsoftwaretoreadthetransceiverfrequency,thefrequencywillappearinthiswindow.Ifyou’renot,youcanrightclickyourmousecursorinthiswindowandselectfromthelistofcommonJT65frequencies.WhywouldyoubothershowingyouroperatingfrequencyintheQRGwindow?Theansweristhatif

you’vecheckedtheENABLERBandENABLEPSKRwindowsJT65-HFwillautomaticallyaccessyourhomeInternetconnectionandshareyourdata(thestationsyou’veheardandhowstrongtheywere)withW6CQZ’sreversebeacon(RB)websiteandwiththePSKReporter(PSKR)website–ifyou’veenabledthisfeatureinthestationsetupscreen.Theinformationisextremelyhelpfultoyourfellowamateurswhostudypropagation,experimentwithnewantennasandsoon.Tomaketheinformationuseable,however,

theyneedtoknowyourlisteningfrequency;that’swhattheQRGwindowisallabout.This is alsowhy you normally include your grid square in your first JT65 exchanges. The reverse

beaconsystemsusegridsquarestocalculatetheapproximatedistancebetweenstations.

WatchtheAction

As is thecasesooften inAmateurRadio,when tryinganewoperatingmode thebestpractice is tospendplentyoftimelisteningfirst.Start by looking at the list of JT65 frequencies in Table 4.1. Select a frequency and place your

transceiverintheUSBmode.TunetothatfrequencyandstarttheJT65-HFsoftware.Iftherearestationstransmitting,you’llsee themin thewaterfalldisplayrightaway.Youmaynotice that theirsignal tracesseemtocurvesomewhatbeforesettlingintoaregularpattern.That’sasymptomofJT65-HFrunningitssamplecorrectionroutineonyoursounddevice.

Wheneveryonestopstransmittingataboutthe48-secondmark,usetheopportunitytoquicklyadjusttheaudiogaincontrolstoachieve0dBonbothchannels.As thenextminutebegins, you shouldhearor seeother stations starting their transmissions. Just sit

backandwatch.You’llnotice thateach transmission iscomprisedofa line–possiblyabroken line–withseveraldotsappearingtotheimmediateright.Thelinerepresentsthesynchronizingtoneandthedotsarealltheremainingtones.When theclockreaches the48-secondpoint,everyoneshouldstop transmittingautomatically.Within

thenextfewsecondsyoushouldseetextappearinthewindowatthelowerleft.Some of the text may be highlighted in green. These are stations calling CQ. You’ll see other text

shadedingray.Thesearetheactualexchanges.Look at the sample decoding screen inFigure4.2 and I’ll explainwhat you are seeing. First, let’s

deciphertheheadingsalongthetopofthewindow,beginningatthefarleft.

UTC:ThetimethesignalwasdecodedinUTC.Sync:Thisisameasurementofthestrengthofthesynchronizingtone.Thehigherthenumber,thebetter

thesyncsignal.dB:ThestrengthoftheJT65signalindecibels.Thelowerthenumber,thestrongerthesignal.ZerodB

isthestrongestpossible.DT:Howmuchthedecodedstation’stimedeviatedfromyourtime,measuredinsecondsorfractions

of seconds. Ideally the decoded stations should be within two seconds of your computer’s time,preferablylessthanonesecond.Evenso,I’veseenJT65-HFsuccessfullydecodestationswhosesignalsdeviatedbyasmuchaseightseconds.DF: How far the signal frequency deviates, in Hertz, above or below the zero center point of the

waterfalldisplay.Anegativenumber isasignal to the leftofzero;apositivenumber isasignal to therightofzero.Exchange: The text the transmitting station actually sent. If you see two call signs, the transmitting

stationisthesecondcallsign.Justtotheleftoftheexchangetextyou’llseeeitheraBoraK.Thisisareferencetothekindoferror

correctionalgorithmthatJT65-HFused tovalidate the text.Bstands forBM, a simpleReedSolomonalgorithm.KmeansKVASD,amuchmorecomplexalgorithm.OnewaytothinkaboutthisistoimaginethataKmeansthatJT65-HFhadtoworkparticularlyhardtomakesenseofthesignal.Ifso,thisstationmaypresentachallengeifyouattempttocompleteacontact.Asyouobservetheexchangesyou’llprobablyseeapatternemerging.JT65exchangesusually,though

notalways,followastrictsequence.Itgoeslikethis,startingat2102UTC…2102CQWB8IMYFN31WB8IMYhasbegunsendingCQonanevenminutefromgridsquareFN31.

2103WB8IMYN1NASEN72N1NASrepliesandtellsWB8IMYthatheislocatedingridsquareEN72.

2104N1NASWB8IMY-11WB8IMYreplieswithasignalreportof-11dB.

2105WB8IMYN1NASR-15N1NASacknowledgesthesignalreportfromWB8IMYwithan“R”followedbyasignalreport(-15).

2106N1NASWB8IMYRRRWB8IMYsends“RRR,”whichmeans“Roger,roger,roger.”Everythinghasbeenreceivedand the

exchangeiscomplete.

2107WB8IMYN1NAS73N1NASsends73–bestwishes.

2108N1NASWB8IMY73WB8IMYsendshis73aswell.Thecontacthasended.

Insteadofsending73,you’lloftenseestationssendingbitsof“freehand”textinstead.TheyaredoingthisbytypingthetextintotheTXTEXTwindow.Youmayseesomethinglike40WLOOPANT,whichisshorthandfor“I’mrunning40Wtoaloopantenna.”Whileallthismayseemratherperfunctory–itcertainlyisn’taconversation–theexchangequalifiesas

avalidcontact.YoucanuseJT65contactsforARRLawardssuchasDXCCorWorkedAllStates,forexample.

Let’sAnsweraCQ

Once you feel comfortable monitoring JT65 activity, why not try answering a CQ? This can besubstantiallymoreexcitingthanitseems,especiallywhenyourealizethatyouhavetomakechoicesandclickyourmousewithjustsecondstospare.Before you begin, check your computer time calibration andmake sure it is up to date. If you are

runningWindowsVistaorWindows7,openCONTROLPANELandclickonDATEANDTIME.In theDate and Timewindow, click on the INTERNETTIME tab and then click theCHANGESETTINGSbutton.Inthenextwindowselectthetimeserver(IusetheNISTserver)andclickUPDATENOW.Youdon’tnecessarilyneedtodothisbeforeeveryJT65-HFoperatingsession,but itdoesn’thurt. Ifyou’rerunningWindowsXP, youmaywant to consider the free time-synchronizing applicationDimension 4,whichyoucandownloadatWWW.THINKMAN.COM/DIMENSION4/.Install theapplicationandsetitupsothatitloadsandrunsconstantlyinthebackgroundwheneveryoustartyourcomputer.BythetimeyoureadthisbookIsuspectasimilarapplicationwillbeavailableforWindows7aswell.

Finally,reduceyourtransceiver’sRFpoweroutputtoabout50W;youdon’tneed100WtomakeJT65contacts.Ifyouareusinganysortofsoftwaretoreadthetransceiver’sfrequency,startitbeforeyoustartJT65-HF.Ifyouareparticipatinginthereversebeaconsystem,selectyourfrequencybyrightclickingintheQRGwindow,orallowyourtransceivercontrolsoftwaretofillinthewindowautomatically.TunetoaJT65frequency(14.076MHzisoftenagoodchoice)andwatchthetrafficforafewminutes.

You’relookingforCQtransmissionshighlightedingreen.Thegreenlineswillappearassoonasyourcomputerdecodesthesignals,usuallyataboutthe48-to

52-secondpoint.Whenyouseeone,youhaveonlyeightsecondstodouble-clickonthelinetobeginyourreply.Thinkfast!When you double-click on the green CQ line, you’ll see that the text of your transmission appears

automaticallyintheTXGeneratedwindow.Don’tworryaboutselectingtheevenoroddminute;JT65-HF “knows” that youwant to transmit during the next availableminute and itwill select evenor oddaccordingly.

Atthetopoftheminute,whenthetworight-handdigitsread“00,”JT65-HFwillkeyyourradioandbegin transmitting. You’ll seeTX IN PROGRESS in red letters above the ENABLE TX/HALT TXbuttons. This is a good time to check the ALC activity on your radio’s meter. If the ALC activity isexcessive,reducethetransmitaudiofromyourinterfaceorcomputer.JT65-HFwillcontinue transmittingyourmessageuntil justbefore the48-secondpoint.Sitbackand

wait. At the top of the next minute, the other station will begin transmitting. If he received yourtransmissionandreplied,youwillseehistext,whichwillcontainasignalreport,highlightedinredafterJT65-HFdecodesit.Thelineisshadedinredforagoodreason:Youneedtotakeactionimmediately!Quicklydouble-clickontheredlineandJT65-HFwillfillinthetextforyournexttransmission.You’ll

send an “R” to acknowledgehis report followedby a report of your own.JT65-HFwillmeasure the

otherstation’ssignalstrengthandwill insert thenumberforyou.Whentheclockreachesthetopoftheminute,JT65-HFwillbeginsending.

Ifallgoeswell,hisnexttransmissionwillbe“RRR”highlightedinred.Double-clickonthislineandJT65-HFwillfinishthecontactbysending73.

YouAnsweredtheCQ,butHeDidn’tReply.Why?It ispossible that theotherstationsimplydidn’thearyou.IfyouseeanothergreenCQlinefromthe

station,double-clickonthelineandtryagain.It isalsoquitepossible thatheresponded tosomeoneelse. Ifyouseehiscallsign inagrayshaded

line,heisrespondingtoanotherstation.QuicklyclickontheHALTTXbuttonsothatyouwon’ttransmitagainandinterferewiththecontact.

DidHeSendaFreeHandText?Attheendofyourcontacttheotherstationmaysendyouabriefmessage,suchasadescriptionofhis

antennaorhowmuchRFoutputheisusing.Thistextwon’tcontainhiscallsign,soJT65-HFwon’tflagitwithacolorotherthangray.Soifyouseeamessage,howdoyouknowitwasfromhim?LookattheDF(frequencydeviation)portionofthedecodedline.Doesthedeviationfigurematchthe

one that appeared during your exchanges (the text highlighted in red)? If so, that text was from yourpartnerandwasdefinitelymeantforyou.

CallCQ

Whenyou’vebecomecomfortableansweringafewJT65CQs,itistimetotryoneofyourown.WhileitisalmostalwaysbesttohaveTXDF=RXDFenabledinJT65-HF,thisistheoneinstance

whenitisexactlywhatyoushouldnotdo.Thebestwaytoexplainthisiswithahypotheticalexample.Let’ssayyou’vepickedaclearspotinthewaterfalldisplayandyouclickedonthatspottopositionthe

red bracket accordingly. You click the CALL CQ button and JT65-HF responds by generating theappropriatetextandsettingyouuptotransmitonthenextoddorevenminute,dependingonwhichoneyouselected.Youtransmitandreceiveareply.Youdouble-clickonthereplybutyou’velefttheTXDF=RXDF

function on and the station calling you is at some offset (different frequency) from your transmittingfrequency.Whathappens?JT65-HFautomaticallyadjustsyourtransmitfrequencytomatchhis.Theotheroperatorrepliesbydouble-clickingonyourdecodedtext,whichmeansthathisbracketwillshifttomatchyournewtransmitfrequency.Whenhisstationtransmitsyou’lldouble-clickonhistextandyourbracketwillmoveagainbecausehistransmitfrequencyhaschanged.Backandforthyougoasbothofyou“walk”throughthewaterfallchangingfrequencieswitheverytransmissionandcausinguntoldinterference.Thisisnotgood.ThecureistounchecktheTXDF=RXDFboxbeforeyoubeginsendingyourCQ.Thiswillkeepyour

frequencystableundertheredbracketwhiletheprogramshiftstowhateverotherfrequencyisnecessarytodecodetheansweringstation.Itwilllabelthisfrequencywithagreenbracket.

WhensomeonerepliestoyourCQ,you’llseethetexthighlightedinredasbefore.Justdouble-clickonthered linesandJT65-HFwillcreate theproperexchangesautomatically.The trick is to stayonyourtoesandclickontheappropriatelinebeforethenextminutebegins.Otherwise,JT65-HFwillsimplyre-sendthepreviousline.Theotherstationwillbeconfusedandyou’llbothhavetowaitthroughanothersetofexchangestocompletethecontact.

TheJoyofJT65

JT65 on theHF bands has been a boon for amateurs living under the burdens of antenna or powerrestrictions.Atthetimeofthiswriting,thereareamateurswho’vecontacteddozensofcountrieswithjusta fewwatts and indoor antennas. InFigure 4.3 you’ll see a 20-meter dipole antenna that I made bymountingtwoHamstick-stylemobileantennasbacktoback.ThisisaparticularlypoorantennaandyetI

wasabletouseJT65tomakecontactwithstationsontheoppositesideoftheworldwithjust5WofRF.

TheotherinterestingaspectofJT65isthatyoucanoperateinaleisurelyfashionthroughoutmostofthecontact.Youcancarryonaconversationwitha lovedonewhileoccasionallyglancingat theJT65-HFdecodingwindow.Theonlytimeyouneedtoactquicklyisinthat8-to10-secondspanbetweenthetimeJT65-HFdecodesatransmissionandthebeginningofthenextminute.Otherwise,youcankickbackandrelax.

ChapterFive

MFSKandOlivia

TheShortScoopThesetwomodesaresomewhatuncommon,butbothallowyoutoenjoyconversations

underjustabouttheworstconditionsimaginable.

MFSK

MFSK–Multi-FrequencyShiftKeying— is reallya typeof super-RTTY. Insteadofusing just twotonesasRTTYdoes,MFSKusesmanymore.Sixteen-toneMFSK(MFSK16)isthemostcommon.TheMFSKtechniquewasdevelopedduringtheheydayofteleprinterHFcommunicationsasawayto

combatmultipathpropagationproblems,providingreliablepoint-to-pointcommunicationswithrelativelysimpleequipment.Piccolo,forexample,isasimilarmodeusedondiplomaticlinksbetweenEnglandandSingapore"back in theday,"and it typicallyprovidedgoodcopyforanhourafter theRTTYlinkshadfaded out. The technology then was electromechanical, but several very important principles wererecognizedatthetime…•Theperformance(reducederrorrate)improvedasthenumberoftonesusedincreased.•Theperformancewasbestwhentheleastnumberofsymbolswasusedtorepresenteachtransmitted

textelement.• With a special integrating detector, tones as closely spaced as the baud rate could be uniquely

detectedwithoutcross-talk.Piccolousedtwosymbolspertextcharacter—comparethiswith7.5symbolspercharacterforRTTY

andanywherefromthreeto12forPSK31.MFSK16usesonlyone symbolpersignalingelement.WithMFSKmodesthebaudrate(rateatwhichsymbolsaretransmitted)isratherlowerthanthetextrate.ThisisbecauseeachsymbolcarriesmoreinformationinitsfrequencypropertiesthanRTTYorPSK.Whilethismayseemconfusing,thetechniquehastheadvantagethatthelongersymbolsareeasiertodetectinnoise,haveanarrowerbandwidth,andaremuchlessaffectedbymultipatherrors.Piccolooriginallyusedasmanyas32tones,butthemostcommonformusessix.MFSKhasbeentested

withasmanyas64tones;theweaksignalvariantMFSK8,uses32.

AnatomyofanMFSKSignalWhatdoesanMFSKsignalconsistof?Well,themostcommonformuses16tones,sentoneatatimeat

15.625baud,and theyarespacedonly15.625Hzapart.Toput this tonespacing inperspective, recallfromChapter 2 that a “narrow”PSK31 signal ismore than 31Hzwide—twice aswide as the spacebetweenjusttwoMFSK16tones.Eachtonerepresentsfourbinarybitsofdata.Thewholetransmissionis316Hzwide,whichisabit

narrowerthanaRTTYsignal.AndlikeaRTTYsignal,anMFSK16signaleasilyfitswithinthepassbandofa500HzCWfilter. In fact, ifyou’resuffering frominterferenceyoucanuse thesameIF filters forMFSK16thatyou’dusewithRTTY.When you hear anMFSK signal for the first time, you’ll notice its peculiar musical quality. Some

compareittothesoundofanold-fashionedcarnivalcalliope.LikeRTTY,thesignalisconstantamplitude—itdoesnotrequirealineartransmittertomaintainaclean

signal.DrivingthetransmittertoohardonMFSK16willnotmakethesignalanywider.However,keepinmind that theMFSK16dutycycle, likeRTTY, ishigh.Thiscanbehardonyour transceiver ifyouarerunningatfullRFoutput.To ensure that text is received with an absolute minimum of errors, MFSK utilizes an excellent

ForwardErrorCorrection(FEC) technique,usingViterbidecoderroutinesbyPhilKarn,KA9Q,andaclever self-synchronizing interleaver developed forMFSK byNino Porcino, IZ8BLY.The typing rate,evenwithFEC,isover40WPM.Ascomplicatedandarcaneasthismaysound,thebottomlineisthatMFSK16canbesuccessfullydecodedundertrulydreadfulconditions.

OntheAirwithMFSKIfyouare runningWindowsXP there is a piece of dedicatedMFSK software by IZ8BLYknown as

Stream. You can download it free at http://antoninoporcino.xoom.it/Stream/. Unfortunately, StreamdoesnotworkwellwithWindowsVistaor7.You’llotherwisefindMFSKamongtheselectionsinthemultimodesoftwarepackageswediscussedin

Chapter 1. Some of these applications will offer severalMFSKmodes fromMFSK4 all the way toMFSK64.Regardlessofthesoftware,MFSKwillrunperfectlywithanyvoicetransceiverusingthesamesounddeviceinterfaceyou’duseforPSK31orotherHFdigitalmodes.OneoftheadvantagesofsettingupanHFdigitalstationaroundsound-devicesoftwareisthatswitchingfromonemodetoanotherisaseasyasclickingyourmouse.Therearenohardwarechangestoworryabout.MFSK16ismostoftenheardjustabovethesamefrequenciesusedbyPSK31(seeChapter2).Twenty

metersisthemostpopularbandbyfar.Ifyouopttotry20metersfirst,listenbetweenabout14.072and14.076MHzwithyourtransceiverintheUSBmode.Ifyou’dliketohearwhatMFSK16soundslike,goto theGet On the Air With HF Digital website atwww.arrl.org/HF-Digital and listen to the audiosample.Depending on the software you are using, youmay discover that tuning anMFSK16 signal takes a

certainamountofpatience.Becausethetonesarecloselyspacedandthesoftwaredecodingfiltersverynarrow,youmusthaveastabletransceiverandyoumustusethetuningprovidedwiththesoftware(inthewaterfalldisplay).Inthewaterfallyou’llnoticealinethatoccasionallyappearsalongtheleft-handsideofthecolumnofdotsthatmakeuptheMFSK16signal.Thisistheidlecarrier,thelowestofthe16tones.Thiscarrieristransmittedbrieflyatthestartandendofeachtransmission,orwhenevertheoperatorstopstyping.Ifyoursoftwareusesa“tuningbracket”inthewaterfall,youneedtomovetheleft-handedgeofthisbracketuntilitisontopoftheidlecarrierline.

Eachtimeyounudgethebracket,waitforseveralsecondstogivethesoftwaretimetosynchronizeandbegindecoding.Ifthebracketisn’tinthecorrectposition,you’llseegibberishtextornothingatall.Onceyou’vefoundtherightspot,almostperfecttextwillstarttoappearonthescreen,althoughit is

delayedbysome3-4secondsasthedatatricklesthroughtheerrorcorrectionsystemandappearsoneortwowordsatatime.If you have found someone calling CQ, you can answer them easily. Just wait until they stop

transmittingandthenclickonthebuttonyoursoftwareusestokeyyourtransceiver.YourinterfaceshouldsendtheMFSK16audiotoyourradioandawayyougo!Leisurelytypeinthetransmitbufferwindowandthenclicktheappropriatesoftwarebuttontoreturntoreceive.Whentheotherstationtransmitsyouwillnoticethatafewsecondsmaypassbeforetextbeginstoappear.Thisisnormal.AllmultimodesoftwareincludesmacrosthatyoucancertainlyuseinyourMFSK16conversations,but

thetraditionistocarryonthechats“manually”withouttheuseofmacros.

PerformanceForQSOsusingshortpath,sayatdistancesto8000mileson20meters,MFSK16worksfine,butyou

mayfindPSK31easier touse. Ifyouare interested in low-powerQRPoperating, there isnotmuch tochoose between the two. On long path, over the poles, and in really difficult conditions whereinterferenceorinstabilityisthemajorproblem,MFSK16isinaclassbyitself.Itjustkeepsgoing,givingalmostperfectcopywhenthesignalisbarelyaudible.Highpowerisn’tnecessary.

MFSK16isoneofthebestconversationalmodesyetfordigitalworkonthelowerbands.Ifyouareintotraffichandling,orsendingbulletinson80or40meters,givethismodeatry.MFSK16willworkoverthousandsofmileson80metersatnight,runningonewattandwith90%perfectcopy.That’swhythe ARRL’s Headquarters station W1AW includes MFSK16 among its digital modes for bulletintransmissions.

Althoughnotnoticeablybetteronthelowbands,MFSK8isgreattohavewhenthebandstartstodie.ItisdefinitelymoresensitivethanMFSK16,andalthoughtuningisverytight,andtypingspeedisdownto25WPM,itwillallowyoutocompletetheconversationwithalmostperfectcopy.WithMFSK16itmayalsobepossibletoswapmorethantext.Somemultimodeprogramswillallow

you to send tiny images within anMFSK16 conversation. For example,MixW forWindows softwaresupports this image function very smoothly. If you’re chatting inMFSK16 and the other station beginssendingan image,MixWwill automatically open a small auxiliarywindowanddisplay the picture. Ifyou’re aMixW user, you can also create amacro to send an imageof your own. Just right click yourmouseononeoftheMixWmacrobuttonsthatyourarely,ifever,useandclearoutwhatevertextisthere.Nowinsertthefollowingtext…

<PIC?N%C>

Givethebuttonalabelyou’llrecognizesuchas“MFSKPix.”WhenyouaretransmittinginMFSK16,click thisbuttonandyou’llbeprompted to selectan image file from theMixW directoryonyourharddrive(putsomefavoriteimagestherefortimeslikethese).Justclickthefilename,thenOPEN.MixWwillimmediatelybeginsendingtheimagetotheotherstation.

Olivia

OliviawasthebrainchildofPawelJalocha,SP9VRC,anditwasnamedafterhisdaughterOlivia.Itisone of the best conversational digital modes in terms of its ability to print readable text in poorconditions.Thesignalcanbedecodedevenwhenitis10to14dBbelowthenoisefloor(i.e.whentheamplitudeofthenoiseisslightlyoverthreetimesthatofthesignal).Itcanalsodecodewellundernoise,fadingandinterference.TheonlyHFdigitalmodethatcanout-performOliviaisJT65,butyoucan’thaveaconversationwithJT65!

Olivia has many formats, some of which are considered standard, and they all have differentcharacteristics.Theformatsvaryinbandwidth(125,250,500,1000and2000Hz)andnumberoftonesused(2,4,8,16,32,64,128or256).Thismakesitpossibletohave40differentOliviaformatsthathavedifferentcharacteristics,speedsandcapabilities.Luckilyonlyafewarecommonlyused.You’llfindOliviainmultimodesoftwaresuchasMixW,MultiPSK,FldigiandHamRadioDeluxe.At

the time this bookwent to press,Oliviawasnot offered in the twomost popularMacOS programs:cocoaModemandMultiMode.The standard Olivia formats (bandwidth/tones) are 125/4, 250/8, 500/16, 1000/32 and 2000/64.

However, the most commonly used formats in order of use are 500/16, 500/8, 1000/32, 250/8 and1000/16.AftergettingusedtothesoundandlookofOliviainthewaterfall,though,itbecomeseasiertoidentifytheformatwhenyouencounterit.About98%ofallcurrentOliviaactivityontheairisoneofthesevenfollowingconfigurations:1000/32,1000/16,500/16,500/8,250/8,250/4and125/4.CommonOliviafrequenciesareshowninTable5.1.Oliviaannouncesitselfwithamusicalsoundnot

unlikeMFSK16,but itwillappear tobewider in thesoftwarewaterfalldisplay.Youcan listen to thesoundofatypicalOliviasignalattheGetOntheAirwithHFDigitalwebpageatwww.arrl.org/HF-Digital.

OntheAirwithOliviaPlace your transceiver in the Upper Sideband (USB) mode and start tuning around. If you suspect

you’vefoundanOliviasignal,observeitsappearanceinyourwaterfalldisplay.ChooseanOliviamodefromyoursoftwareMODESmenuthatresultsinatuningbar(orbracket)thatappearstomatchthewidthof the Olivia signal in the waterfall. Position the bar on the signal and wait patiently. If you thoughtMFSK16wasslowtodecodeandprint,Oliviacanbemuchslower.That’soneof thetradeoffsOliviamakesforitsamazingperformance.Ifyoudon’tseecoherenttextafter15secondsorso,youmayhavechosentherightbandwidthbutthe

wrongnumberof tones.Quicklygobackto theMODESmenuand tryagainwithadifferentnumberoftonesinthesamebandwidth.AnexperiencedOliviaoperatorknowsthatthisinitialdecodingprocesscantakeawhile,sohewill

usuallysendaverylongCQ.AnOliviaCQlastingmorethanaminuteisnotuncommon.Theideaistogivelistenersplentyoftimetolockinthesignal.Withthat inmind, it isagoodideatocreatea longCQmacroforOlivia thatyoucantriggerwitha

singleclickofyourmouse.ItcertainlybeatshavingtomanuallytypeaverylongCQeachtime!Ifyousoftwaresupportsit,trycreatingan“AutoCQ”macro.ThismacrosendsalongCQ,pausesfor

aboutaminutethensendsagain.TheAutoCQfunctionwillallowyoutoputteraboutyourstationwhileyouwaitforsomeonetotuneyouinandanswer.SinceOliviaisnotascommonontheairasPSK31,thismaytakesometime.Once you’ve established a conversation, sit back, relax and enjoy. Olivia moves at a slow pace,

printingonlyafewwordsonyourscreenatatime.Thisresultsinconversationsthatmaylastasmuchasanhour,perhapsevenlonger.Justwatchthe text in thereceivewindowandtypeyourresponses in thetransmitwindow.Youdon’thavetowaitfortheotherstationtostopbeforetypingyourresponses.Onthecontrary, you can enter your commentswhile the other station is still transmitting.When you enter thetransmitmode,they’llbesentautomatically.

OliviaHintsThereareafewthingsyoucandotoimprovehowwellOliviaworksatyourstation.Someofthese

tipsmaynotnecessarilybesupportedinthesoftwareyouareusing,butchancesarethatmostwill.•Ifyourmultimodeapplicationhasasoftwaresquelchfunction,setitto“low”or“off.”Yes,this

settingwillproducesomerandom“garbage”textonyourscreen,butitwillalsoallowyoutoreadtextfromveryweakOliviasignalsthatwouldotherwisebeinvisible.•ExerciseCQpatience.We’vetouchedonthisalready,butitbearsrepeating.WhenyoucallCQon

thismodebepatientandwaitatleast45-60secondsbeforeyoucallagain.Rememberthatthelistening

stationmay be effectively 5-20 seconds “behind” you, still decoding your signal after you’ve stoppedtransmitting. Ifyou instantlyhit theCQmacrobuttonagain, theother fellowmaystillbedecodingandwon’tbeabletorespond.Waitsothathehasplentyoftimetodecodeallyourtextandbegintransmittinghisreply.

•Don’tgetcarriedawaywithyourSyncIntegrationPeriod.Thissoftwaresetting(someprogramsmay label it differently) determines how “deep” the software digs into the data to decode an Oliviasignal.Youmaysay,“Setitashighaspossibleformaximumperformance,”butthiswouldbeamistake.Ifyouset thisparameter skyhigh,youmaybewaitingminutes beforeOliviabeginsdecoding.This isclearlyabsurd.Ifyouareindoubt,gowithwhateverthesoftwaredefaultsettinghappenstobe.Feelfreetoexperiment,though.You’lleventuallyfindthatyoucanindeedsqueezeoutbetterperformanceathighersettings.Itisjustamatterofhowmuchdelayyoucaretotolerate.•Keepyour“Search”settingatabout8.TheSearchsetting(orTuneMargin)determineshowfar

fromthecenterfrequency(inthemiddleofthetuningbar)thesoftwarewillgotograbtheOliviasignal.Onceagain,ifyouareindoubt,usethedefaultvalue.

ChapterSix

PACTOR

TheShortScoopAllthemodesdiscussedinthisbooksofarusesounddevicesasmodems.Thisoneis

different–anditessentiallyguaranteeserror-freecommunication.

Hans-PeterHelfert,DL6MAA,andUlrichStrate,DF4KV,developedPACTORin1991.ItremainstothisdaythemostpopularoftheHFburstmodes.TherearenowfourversionsofPACTOR:PACTORI,PACTORII,PACTORIIIandPACTORIV.PACTORIisconsideredobsoleteandislittleused.PACTORIIandIIIareincurrentuse,primarilytoconnecttoautomatedstationssuchastheWinlink2000network,whichwe’lldiscusslater.There is no sound-device softwaremethod for sending and receiving PACTOR. As I mentioned in

Chapter1,theonlywaytogetontheairwithPACTORistouseastand-alonehardwarecontroller(alsoreferredtoasaMultimodeCommunicationsProcessor)thatconnectsbetweenyourcomputerandanSSBtransceiver.We call PACTOR a burst mode because of the way it sends information. Rather than sending a

continuous stream of data like RTTY, PSK31, MFSK16 or Olivia, PACTOR transmits bursts ofinformationthattaketheformofshortdatablocks.Whenthedataisreceivedintact,thereceivingstationsends an ACK signal (for acknowledgment). If the data contains errors, a NAK is sent (fornonacknowledgment).Insimpleterms,ACKmeans,“I’vereceivedthelastgroupofcharactersokay.Sendthenextgroup.”NAKmeans,“Thereareerrors in the lastgroupofcharacters; send themagain.”Thisback-and-forthdataconversationsoundslikecricketschirping.InthecaseofPACTOR,thelongchirpisthedataandtheshortchirpistheACKorNAK.

MemoryARQ

InlesssophisticatedburstmodessuchasAMTORorpacket,adatablockmustberepeatedoverandover if that’s what it takes to deliver the information error-free. This results in slow communication,especiallywhenconditionsarepoor.PACTORhandlesthechallengeof“repairing”errorsinaninterestingway.Asstatedabove,eachdata

blockissentandacknowledgedwithanACKsignalifit’sreceivedintact.Ifsignalfadingorinterferencedestroys some of the data, aNAK is sent and the block is repeated.Nothing new so far—packet andAMTORbehavemuchthesameway.Thebigdifference,however,involvesmemory.WhenaPACTORcontrollerreceivesamangledcharacterblock,itanalyzesthepartsandtemporarily

memorizeswhatever informationappears tobeerror-free. If theblock is shot fullofholeson thenexttransmissionaswell,thecontrollerquicklycomparesthenewdatafragmentswithwhatithasmemorized.

It fills the gaps as much as possible and then, if necessary, asks for another repeat. Eventually, thecontrollergathers enough fragments to construct the entireblock (seeFigure6.1). PACTOR’smemoryAutomaticRepeatreQuestfeaturedramaticallyreducestheneedtomakerepeattransmissionsofdamageddata.Thistranslatesintomuchhigherthroughput.

PACTORhasthecapabilitytocommunicateatvaryingspeedsaccordingtobandconditions.PACTORthroughputisenhancedbyusingHuffmancodingthatreducestheaveragecharacterlengthforimprovedefficiency.

WhatDoYouNeedtoRunPACTOR?

AssemblingaPACTORstationisverysimple.Allyouneedarethefollowing:•AnSSB transceiver.The output of thePACTORcontroller is audio,which can be applied at the

microphone or accessory jack. The controller also operates the transmit/receive keying line. The onlycatchisthatthetransceivermustbecapableofswitchingbetweentransmitandreceiveinlessthanabout20 milliseconds. Most modern transceivers meet this requirement. If you’re unsure, check the QSTmagazineProductReviews.TheARRLLabroutinelyteststhisfunctionineverytransceiverreview.•AcontrollerwithPACTORcapability.CurrentcontrollersbyTimewaveandolderKantronicsand

AEA controllers support PACTOR I, but only controllers manufactured by Special CommunicationsSystems(SCS)offerPACTORII,IIIandIV.•Acomputerrunningthecontroller’scompanionsoftware.Mostcompatiblesoftwareiswrittenfor

MicrosoftWindows.WhenassemblingyourPACTORstation,usetheguidelinesdiscussedinChapter1.Theconnectionto

thecomputerismadewithaserialcableinoldercontrollers,soyoumayneedaUSB/serialadapterifyourcomputerdoesn’thaveaserialport.ThelatestSCSPACTORunitsofferaUSBconnection.

CQPACTOR

AlthoughmostPACTORactivityinvolvesconnectingtoautomatedsystems,youcanstilloccasionallyenjoya“live”conversation.You’lltendtofindtheseinthesamefrequencysegmentsusedforRTTY(seeChapter3).YoucallCQonPACTORusing forwarderrorcorrection,orFEC.TheFECsignalsounds likevery

fastRTTY,butinrealityitisastreamofdatainwhicheachcharacterisrepeatedtwiceforredundancy—therearenoACKsorNAKs.Obviously, thismeans thatanFECtransmission isnoterror-free,but thecopyisgoodenoughtopulloutthecallsignofthesendingstation.Whenyou’resendingaPACTORCQ,that’sreallyallthatmatters.If you hear a signal that you suspect is a PACTOR FEC CQ, tune carefully until your controller

indicatesthatithaslocked(synchronized)withtheFECsignal.Withinashorttime,youshouldbegintoseetextonyourscreen.

CQCQCQDEWB8IMYWB8IMYWB8IMYCQCQCQDEWB8IMYWB8IMYWB8IMYCQCQCQDEWB8IMYWB8IMYWB8IMYKK

Notice that thisCQuses several short linesof text rather thana few long lines.Thishelps stationssynchronizemoreeasily.

StartingaConversation

AnsweringaCQinPACTORisstraightforward.Dependingonthesoftwareyou’reusing,itmaybeassimpleasentering:CALLN1BKEor,CONNECTN1BKE

at thecmd:prompt.Some typesof software streamline theprocesseven further.Theremaybepop-upboxeswhereyousimplyenteracallsign.Onceyoumakecontact,theconversationproceedsinturns.Thismeansthatonestation“talks”(theISS

orinformationsendingstation)whiletheother“listens”(theIRSorinformationreceivingstation).WhentheISShashadhissay,hesendsaspecialcontrolsignalknownastheovercommand that immediatelyreverses the roles—suddenlyyou are the ISS andhe is the IRS. Introduceyourself and ask aquestionabout where he lives, or what he does for a living. Use the over command to flip the link again. Aconversationisunderway!Dependingonthesoftwareyouareusingwithyourcontroller,sendingtheovercommandisusuallyas

easyastappingasinglekey.Thesoftwareusuallyprovidessomesortofvisualindicatortoshowwhichmodeyouare in—IRSor ISS—incaseyoubecomeconfused! Ifyouforget tosend theovercommand,your stationswill simplysit thereandchirpmindlesslyateachother.Fortunately, the IRScansendanovercommandandflipthelinkforyouifnecessary.Thisisknownasa“forcedover.”

PACTORII

You can think of PACTOR II in terms of being a supercharged version of PACTOR I. In goodconditions,PACTORIIboastsadatatransferrateuptosixtimesfasterthanPACTOR.Atthesametime,PACTORIIiscapableofmaintaininglinksinconditionswherethesignal-to-noiseratioisat-18dB.Thismeans that PACTOR II can carry on an exchange evenwhen the signals are virtually inaudible. Suchremarkable performance is also conservative when it comes to bandwidth; a PACTOR II signal onlyoccupiesabout500Hzofspectrum.

Thecomplexpi/4-DQPSKmodulationsystemusedbyPACTORII requiresDSP technologyandfastmicroprocessors.WithDSP,youletthesoftwaredecidethecompositionofthesignal,notthehardware.DSP ismuchmore flexible, allowingyou to create the signalyouwantwithouthaving toworry abouthardwarefiltersandsoon.Thetradeoffisthatyoumustusehigh-speedmicroprocessorstohandlealltheincoming and outgoing information at a decent rate. That’s part of the reason why PACTOR isimplementedbySCSindedicatedhardwarecontrollers.PACTOR II is also backward compatible with PACTOR I. That is, a PACTOR II operator can

communicatewithaPACTORIoperatorandviceversa.

PACTORIIStationRequirementsandOperation

TherequirementsforaPACTORIIstationareessentiallythesameasforaPACTORIstation:AnSSBtransceiver,acomputerordataterminalandaPTC-IIorPTC-IIeprocessor.PACTOR II also operates in nearly the same fashion as PACTOR I. In fact, the link is initially

establishedusingthePACTORIprotocolandthenautomaticallyswitchedtoPACTORIIifbothstationsareusingPACTORIIprocessors.AndaswithPACTORI,youmusttaketurnsduringtheconversation,

sendinganovercommandtoallowtheotheroperatortosenddata.

PACTORIII

PACTORIIIwas introducedbySCS in2001asa firmwareupgrade to theirPTClineofmultimodecontrollers.Whenthiseditionwenttopress,PACTORIIIwasbeingusedprimarilyintheWinlink2000network,althoughupgradedcontrollersremain“backwardcompatible”withPACTORIandII.PACTORIIIrepresentsasubstantialimprovementwithitstwo-dimensionalorthogonalpulseshaping,

advanced error control coding and efficient source coding. It provides excellent performance in poorsignalconditionsandachieveshighthroughputratesundergoodsignalconditions.Thetradeoff,however,is the fact that a PACTOR III signal occupies a 2200Hz bandwidth, asmuch as a typical SSBvoicetransmission. For this reason, PACTOR III stations often operatewell above the frequencies used forPSK31, RTTY and othermodes. For example, on 20meters youwill often hear PACTOR III signalsbetween14,103and14,115kHz.ThekeybenefitsofPACTORIIIare:•HigherthroughputcomparedtoPACTORII.Underaveragesignalconditions,aspeedgainfactorof

3-4ispossible.Underverygoodconditions,PACTORIIIcanbeasmuchasfivetimesfaster.•Amaximumdatarateof2700bitspersecondwithoutcompression.Withtextcompressionapplied,a

datarateof5200bpsispossible.AswithPACTORII,youmustpurchaseanSCSmultimodecontrollertousePACTORIII.Thismodeis

notavailablefromanyothermanufacturers.

PACTORIV

SCS unveiled PACTOR IV in early 2011with the introduction of theirmodel DR-7800multimodecontroller.ThebigdifferencebetweenPACTORIVandPACTORIIIisspeed.ThePACTORIVprotocolboastsasymbolrateof1800baudwithina2400Hzbandwidthusing10speedlevels,DBPSK/DQPSK(non-coherent, spreading factor 16), BPSK-32QAM (coherent) and adaptive equalizing. All thistranslatesintoastonishingthroughputthatispotentiallymorethandoublethatofPACTORIII.SqueezingthatkindofHFdigitalperformanceintoa2400Hzbandwidthrequiredyearsofpainstakingwork.

Unfortunately,PACTORIV isnot legal for amateuruseon theHFbands.Below28MHzAmericanamateurs are restricted to data modes with effective symbol rates of 300 baud or less. PACTOR IVexceeds this limitsubstantially.On theotherhand,sinceMilitaryAuxiliaryRadioSystem(MARS)HFoperations take place outside the amateur bands, they aren’t hobbled by that restriction.They’ve been

usingPACTORwiththeWinlinknetworkforanumberofyears,sotheDR-7800andPACTORIVcouldprovetobeapowerfulnewtoolforUSamateurswhoparticipateinMARS.

Winlink2000:TheHFE-MailConnection

TheInternethasbecomethemessagemediumofchoiceformosthams.ButthereisasizeablegroupofamateurswhooftentravelbeyondthereachoftheInternet.Thisgroupincludeshamsatsea,travelersinrecreational vehicles (RVs),missionaries, scientists and explorers.No doubt the daywill comewhenwireless,affordableInternetaccesswillbeavailablefromanypointontheglobe.Untilthatdayarrives,however,theAmateurRadioHFdigitalnetworkisaverycapablesubstitute!

TheEvolutionofWinlink2000DozensofdigitalstationsworldwidehaveformedaremarkablyefficientInternetinformationexchange

network, includinge-mailandbinaryfile transfers.SeeTable6.1.RunningWinlink2000softwareandusingmostlyPACTORIIorIII,thesefacilitiestransferinformationbetweenHFstationsandtheInternet.TheyalsoshareinformationbetweenthemselvesusingInternetforwarding.Thenetworkevolvedinthe1990sfromtheoriginalAMTOR-basedAPLink system,authoredbyVic

Poor,W5SMM.APLinkwasanetworkofstationsthatrelayedmessagestoandfromeachotherandtheVHFpacketnetwork.AsPCsbecamemorepowerful,andasPACTORandCloversupersededAMTOR,anewsoftwaresystemwasneeded.ThatneedbroughtaboutthedebutofWinlink,authoredbyVicPoor,W5SSM,withadditionsfromPeterSchultz,TY1PS.WinlinkitselfevolvedwithsubstantialenhancementscourtesyofHansKessler,N8PGR.TobringtheInternetintothepictureWinlinkstationsneededane-mail“agent”tointerfacewithcyberspace.TomeetthatrequirementSteveWaterman,K4CJXenlistedthehelpofJimJennings,W5EUTandRickMuething,KN6KB,toaddNetLink.Early in 2000 the system took the next evolutionary leap, becoming a full-featured Internet-to-HF

gateway systemknownasWinlink2000 or “WL2K.” JimCorenman,KE6RK, concurrently developedsoftwarecalledRMSExpress,whichistheend-userportionofWinlink2000.Winlink2000isanetworkofparticipatingstationsknownasRMSradiogateways,allconnectedtoacentralserverthatfunctionsasthe“hub”forconnectivitytoInternete-mailandpositionreporting.

Thanktotheseadvancements,anHFdigitaloperatoratsea,forexample,cannowconnecttoaWinlink2000 participating network station using RMS Express software and their PACTOR controller andexchange Internet e-mailwith non-ham friends and family.He can also exchangemessageswith otheramateursbyusingtheWinlink2000networkstationsasatraditionalglobal“mailbox”operation.

MostWinlink2000participatingstationsscanavarietyofHFdigitalfrequenciesonaregularbasis,listeningoneachfrequencyforabouttwoseconds.Byscanningthroughfrequenciesonseveralbands,theWinlink2000stationscanbeaccessedonwhicheverbandisavailabletoyouatthetime.UsingRMSExpress,Winlink2000featuresinclude…•Text-basede-mailwithbinaryattachmentssuchasDOC,RTF,XLS,JPG,TIF,GIF,BMP,etc.• Position inquiries accessible fromboth the Internet graphically viaAPRS andYotReps, e-mail or

radiototrackthemobileuser.•Graphicand text-basedweatherdownloadsfroma listofover400weatherproducts,covering the

entireglobe.•Pickupanddeliveryofe-mailregardlessoftheparticipatingstationaccessed.• End-user control of which services and file sizes are transmitted from the participating stations,

includingtheabilityforeachusertore-directincominge-mailmessagestoanalternatee-mailaddress.•TheabilitytousetheInternetviaTelnetinsteadofaradiotransmission.•TheabilitytouseanyWebbrowsertopickupordelivermailoverWinlink2000.

HardwareandSoftwareRequirements

In addition to your HF SSB transceiver, you’ll need a PACTOR controller that is capable ofcommunicatinginbinarymodewitheitherPACTORI,IIorIII.Atthetimethisbookwaspublished,onlyfiveprocessorsmetthisrequirement:•SCSPTC-II(inallitsvariations)•KantronicsKAM+orKAM98•Timewave/AEAPK-232RMSExpress software is required toaccessWinlink2000.YoucandownloadRMSExpress freeof

chargeatwww.winlink.org/ClientSoftware.Itcontainsaspell-checkerandhasthelookandfeelofane-mail“agent”suchasOutlookExpress.RMSExpresswillhandleallthecommunicationwithyourPACTORcontroller;youdon’tneedtohave

aseparatepieceofsoftwarerunningonyourcomputer.Ifyourtransceiveriscapableofcomputer(CAT)control,RMSExpresswillevensetyourfrequencyautomatically tomatchthefrequencyof theWinlink2000radiogatewaystationyouaretryingtoreach.

AccessingaWinlink2000Station

InformationaboutgettingstartedwithWinlink2000maybefoundatwww.winlink.org/GetStartedorwithintheRMSExpresshelpfiles.Inanutshell,youbasicallycomposeyourmessagejustasyouwouldinInternete-mail.Whenyouclick

the SEND button, RMS Express will access your PACTOR controller and attempt to connect to theWinlink2000 station. If the connection fails, itwill try again later or give you the option of choosinganotherstation.Whenyoufinallyconnect,RMSExpressonceagainbehavesjustlikeanInternete-mailclient.Itwill

uploadyourmessageandthen“ask”theWinlinkstationifyouhaveanymailwaitingforyou.Ifso,itwilldownloadyourmailautomatically.Remember thatWinlink2000 stationsusually scan through several frequencies. If you can’t seem to

connect,theWinlink2000stationmayalreadybebusywithanotheruser,orpropagationconditionsmaynotbe favorableon the frequencyyou’vechosen.Either tryagain later,oruse thebuilt-inpropagationfeaturetoconnectonanotherband.

SendingE-mailToandFromtheInternetFromtheInternetsideofWinlink2000,friendsandfamilycansende-mailtoyoujustastheywould

sende-mailtoanyoneelseontheNet.Infact,theideaofWinlink2000istomakeHFe-mailexchangeslookessentially thesameasregularInternete-mailfromtheuser’spointofview.Internetuserssimplyaddress their messages to <your call sign>@winlink.org. For example, a message addressed towb8imy@winlink.orgwillbeavailabletomewhenIcheckintoanyWinlink2000station.ThroughtheRMSExpresssoftwarethehamusercanaddressmessagestonon-hams,ortootherhams,

forthatmatter,byusingthesameformatusedinanyothere-mailprogram.AlthoughWinlink2000supportsfileattachments,rememberthattheradiolinkisveryslow(especially

compared to the Internet).Sendinganattachmentofmore than40,000bytes isusuallynotagood idea.Text,RTF,DOC,XLS, JPG,BMP,GIF,WMO,GREBandTIF files arepermitted as longas theyaresmall enough to comply with the particular user-set limit.Where possible,Winlink 2000 compressesfiles.Forexample,a400,000byteBMPfilemaybecompressedtounder15,000bytes.However,thisisanexceptionratherthantherule.

WINMORAdiscussionoftheWinlink2000networkwouldbeincompletewithoutmentioningWINMOR.Unlike

the PACTOR controllers we discussed in this chapter,WINMOR is indeed sound-card based. ThisrelativelynewsoftwareoffersasolutiontothosewhowanttoaccesstheWinlink2000networkbutdon’townaPACTORcontroller.WINMORworksperfectlywithRMSExpressastheWinlinke-mailclient.WINMORwilloperatewithjustaboutanysound-device-basedstationandSSBtransceiver.Ifyouare

setup tooperatePSK31,youarealsoable to runWINMOR by simplydownloadingand installing thesoftware.SeetheWINMORpageontheWinlink2000websiteatwww.winlink.org/WINMOR.

Inmostdigitalmodesthetransmittingstationsetsthespeedandthereceivingstationmustsetitsspeedtomatch.InWINMORitisthereceivingstationthatdeterminesthespeedandletsthetransmittingstationknow what speed it is accepting automatically. The speed you set in setup only comes into effect ifsomeonecallsyourstationinpeer-to-peermode.OneofthereasonsforthisistheRMSstationsoperatingunattended onAmateurRadio frequencies are limited to a 500Hz bandwidth.MARS stations are notsubjecttothesamerestrictionsoalltheWinlinkMARSstationswillaccepta1600HzbandwidthwhenusingWINMOR.Withineachbandwidththereareanumberofdifferentmodesthatmaybeoperating.Thesechoicesare

not under the operator’s control and are determined by the signal strength, propagation conditions,multipathing,noiseand interferenceand thebandwidth setby the receivingstation. Inotherwords, theprogramshiftsgearstogetthebestthroughputunderchangingconditions.

Appendix

ZenandtheCasualRTTYContester

TheShortScoopWinningisn’teverything,grasshopper.

Justplayingthegameisitsownreward.

SteveFord,WB8IMY

Withamodeststationandahunkofwireinabackyardtree,myoddsofplacingintheTopTenofanAmateurRadiocontestarecomparabletomyoddsofwalkingontheMoon–notimpossible,buthighlyunlikely.So,whybotherwithcontestingatall?Theanswerisfoundinthemaximthatthejourneyisoftenmoreimportantthanthedestination.Ifyou’ve

everspentanafternoonfishing,youknowwhat it is like tocastyour line into thewaterandwatch thebobberasitfloatsserenelyonthesurface.Youbecomeonewiththebobberandthewater–atrueZenexperience.Suddenlythebobberplungesintothemurkydepthsandthelinegoestaut.It’sabite!Yougrabthepole

withyourheartpoundingandstartreelingin...analgae-encrustedtwig.Okay,itwasn’tanaward-winningbassafterall,butforafewprecioussecondsyousavoredtheexcitingpossibility.Youunhookthetwigandcastyourlineagain.Maybenexttime.Thethrillofcontestingisverymuchthesame.AZencontestmasterknowsthattherewardisnotinthe

win,butinthepursuit.Therewardisfoundinpushingthelimitsofyourphysicalandmentalstaminatoachievewhatevergoalyou’vesetforyourself–evenifthatgoalisdefinedasmaking50contactswhilere-roofingyourdoghouse.YoumayneverachievetheOlympiansummitoftheTopTen,butyou’realwaysa“winner”nonetheless.Iamwhatisknownasacasualcontester,atthe“grasshopper”endoftheZenscale.Wearelegionin

theAmateurRadiocontestingworld.Asmuchaswe’dlovetospendanentireweekenddoingbattlewithourradios,lifemakesotherdemands.Therearelawnstocut,homesinneedofrepair,familiesinneedofourattentionandsoon.Wehavetofitourcontestingenjoymentintoourotherwisebusyschedulesanddoit inaway that is compatiblewitheverythingelsegoingonaroundus.When lifebecomesadomesticjugglingact,RTTYlooksawfullyattractivefromacontester’spointofview.

TheTaoofRTTY

With the possible exception ofCW,RTTY is one of the oldest digital operatingmodes inAmateurRadio.Insimpleterms,youcommunicatewithRTTYbygeneratingaradiosignalthatshiftsbetweentwofrequenciesatarapidrate.ThisiswhatgivesaRTTYsignalitsdistinctiveblee-blee-bleerhythm.Atthereceivingend,theshiftingsignalisdecodedintoletters,numbersandalimitedpunctuationset.In the good old days, RTTY operators used terminal units to generate the transmitted signals and

decodethereceivedsignals.Somehamsstilluseterminalunits,butthemajorityhaveswitchedtoRTTYsoftwarethatusesthecomputersoundcardtoperformthesametask.

Althoughitisn’tasnarrowasaCWorPSK31signal,RTTYstillmanagestoconcentrateenergywithinless than 500 Hz of spectrum, which enhances its ability to be received and decoded when bandconditionsaremarginal.ThisiswhyRTTYremainspopularamongdigitalDXhuntersandcontesters.RTTYisn’tthefastestdigitalmode,butitisreasonablypeppy,streamingalongatabout45wordsper

minute.Brevityisthesoulofwitinacontest–andsoisspeed.ThefactthatmodernRTTYisacomputer-basedmodemakesithighlyattractivetothecasualcontester.

Allyourtoolsaregatheredinoneplace.ThecomputernotonlysendsandreceivesRTTY,withthepropersoftware itcanmaintainyourcontest log, too.And thanks tomacros–pre-programmed tasks thatyourcomputer executes with the press of a single key, such as responding to a CQ – you can become aversatilemultitasker, hunting RTTY contest contacts and doing other thingswith your computer at thesametime.(Ioncecheckedmydaughter’shomeworkwhileparticipatinginaRTTYcontest.)

WhatDoYouNeedtoGetStarted?

TheshoppinglistforacasualRTTYconteststationisremarkablyshort:•AnHFSSBtransceiver•Acomputerwithasoundcard•Asound-card-to-transceiverinterface•SoftwareMy guess is that you already have most of the above or you wouldn’t have read this far. Of the

remainingitems,thesoundcardinterfaceisthehardwarethatallowsyoutoshuttleaudiobetweenyourradioandyourcomputer.Italsohandlestransmit/receiveswitching.YoucanbuyaninterfacefromQSTadvertisers such as MFJ Enterprises (www.mfjenterprises.com), West Mountain Radio(www.westmountainradio.com)orTigerTronics(www.tigertronics.com).Youcanalsomakeyourown.The software can be just about anything thatwill use your sound card to do the tricks necessary to

transmit and receive a RTTY signal. A partial list is shown in the “RTTY Software” sidebar. Somesoftwaretitlesarefree.Strictlyspeaking,youdon’tneedcontest-loggingsoftware,butitsuremakeslifeeasier.Notonlydoes

thesoftwarelogallyourcontacts,itautomaticallychecksforduplicatecontacts,betterknownasdupes.Dependingontherulesofthecontest,youmayonlybeallowedtocontactthesamestationonce,oronceperband.Duplicatecontactsareawasteoftimeandshouldbeavoided.Therearecontest-loggingsoftwarepackagesthatincludetheabilitytosendandreceiveRTTY.Others

allowyoutoincorporatestandaloneRTTYprograms.BrowsethewebandtheadvertisingpagesofQSTandyou’llfindthatyouhavemanychoices.I could devote several pages describing how to set up a RTTY station, but there is an excellent

resource that is as close as your computer keyboard. RTTY contest master Don Hill, AA5AU, has asuperb web page that will give you all the detail you need. Get on the web and go to:www.aa5au.com/rtty. Also, the manuals that accompany commercial sound card interfaces offerguidanceonhowtosetupyourstation.

RTTYSoftwareThisisonlyapartiallist.SeetheadvertisingpagesofQSTorsearchthewebformore.

WindowsRCKRTTY:www.rckrtty.de/WriteLog:www.writelog.comMMTTY:hamsoft.ca/pages/mmtty.phpTruTTY:www.dxsoft.com/MixW:mixw.net

MacMultimode:www.blackcatsystems.com/software/multimode.htmlcocoaModem:www.w7ay.net/site/Applications/cocoaModem/index.html

LinuxLinPSK(RTTYandPSK31):linpsk.sourceforge.net/Fldigi:www.w1hkj.com/Fldigi.html

It’s important to mention that once you’ve established your RTTY station, you can use the samehardwaretooperatePSK31,MT-63,Hellschreiber,slow-scantelevisionandmanyothermodes.Allyouhavetodoisloadadifferentprogram.That’sapowerfulincentivetogetstarted!

BigGunsvsLittlePistols

WithBigGunconteststations,bigistheoperativeword–bigantennasandbigpower.We’retalkingtowersandkilowatts.Somecontestoperationsconsistofseveraloperatorsworkingseveraltransceiversatthesametime.Thisisthemulti-multijuggernaut.Ifyoueverhaveanopportunitytojoinamulti-multiteam, I highly recommend it. The team atmosphere is intoxicating. It’smore fun than a ham should beallowedtohave.

Whatabouttherestofus?We’retheLittlePistols(orLittlePopGun,inmycase).Believeitornot,wearehighlyvaluabletotheBigGunsdespiteourreducedprofiles.Canyouguesswhy?Theansweristhateverystation,nomatterhowsmall,representsapointinacontest.AndifyouareluckyenoughtoliveinaplacethathasfewRTTYoperatorsinresidence,youareevenmoredesirableasararemultiplier.

TheValueofMultipliers

Everycontesthasmultipliers.TheseareUSstates,DXCCentities,ARRLsections,gridsquaresandsoon,dependingontherulesofthecontest.Amultiplierisvaluablebecauseitmultipliesyourtotalscore.Let’ssaythatDXCCentitiesaremultipliersforourhypotheticalcontest.You’veamassedatotalof200

pointssofar,andindoingsoyoumadecontactswith50differentDXCCentities.200×50=10,000pointsThose50multipliersmadeahugedifferenceinyourscore!Imaginewhatthescorewouldhavebeenif

youhadonlyworked10multipliers?Ifgivenachoicebetweenchasingastationthatwon’tgivemeanewmultiplierandpursuingonethat

will,I’llspendmuchmoretimetryingtobagthenewmultiplier.SowilltheBigGuns.

HuntingandPouncingvsRunning

ThecommonsenseruleofthumbisthataLittlePistolstationshouldonlyhuntandpounce.Thatmeansthatyoupatrolthebands,watchingfor“CQTEST”onyourmonitorandpouncingonanysignalsyoufind.The Big Guns, on the other hand, often set up shop on clear frequencies and start blasting CQs. Ifconditionsarefavorable,they’llbehaulingincontactslikeatrawler.Thisisknownasrunning.In many cases, Little Pistols are probably wasting valuable time by attempting to run. There are

situations,however,whererunningdoesmakesense.Ifyou’vepouncedoneverysignalyoucanfindonaparticularband, trysendinganumberofCQsyourself tocatchsomeof theotherpouncers. Ifyousendfiveor10CQsinarowandnooneresponds,don’tbothertocontinue.Movetoanotherbandandresumepouncing.Youcanalsorunsuccessfullyifyouareararemultiplier.Nomatterhowweakyoursignalmaybe,all

theotherstationswillcometoyou!As you make each contact, keep your exchanges short. The goal is to communicate the required

information clearly.Anything else is extraneous. Let’s say that you’re involved in a contestwhere theobjectistoexchangeasignalreportandstate…

WB8IMYgivesK1ROa599signalreport(theyareall“599”–oneofthepeculiaritiesofcontesting)andthenrepeatshisstateabbreviationtwice(CT–Connecticut)beforequicklyendingthetransmission.

[WRONG]K1RODEWB8IMY...Thanks for the contact. You are 599 here in the state of Connecticut.Weather here iswonderful.Mywifeisdivorcingmeandmycatiscoughingupahairballinmylap.K1RODEWB8IMYK

ThisismoreinformationthanK1ROislikelytowant–evenoutsideofacontest!Incontesting,timeiscritical. Saywhat you have to say clearly andquickly. In addition, the longer you transmit, themoreopportunitiestherewillbeforerrorscausedbyfading,noiseorinterference.

Therewardsofcasualcontesting,likefishing,areintheeyeofthebeholder,ortheZenmaster.Afewdozencontacts to test thewatersmaysuffice.Oryoumaychoose tobangoutasmanycontactsasyourtimeallows.Intheendyou’lltakehomeacollectionofsoggybranches(minussomehooksandbobbers),oryoumight land themotherof allmuskies.Eitherway,you’ll leave fulfilled, at onewith the contestuniverse.

Appendix

GhostQSOs–OliviaReturnsfromtheNoise

TheShortScoopOlivia–themagicmode.

GaryL.Robinson,WB8ROL

ItwasachillyforebodingfalleveningwhenIfireduptheYaesuFT-100D,startedmyDM780software(partoftheHamRadioDeluxesuite)andparkedmydialfrequencyon1.808MHz.Thewaterfallwasasempty and devoid of signals as a sunspot-starved ionosphere. After listening for almost half an hourwithouthearinganysignals,IdecidedtosettheprogramuptocallCQautomaticallyonceaminute.IsetmymodeasOlivia500/16(500Hzwideusing16toneformat)–adigitalmodeIhadrecently

“discovered”andwasintriguedwith–anddouble-checkedthefrequencytomakesureitwasnotinuse.Iengagedtheauto-CQandreachedformylow-GIrishwhistle–anotherfavoriteendeavorofmine–andcommencedplayingashortlivelyjig.Iroutinelyplaytuneswhensendingauto-CQsandkeepthereceiveraudioatalowlevel.Withoneearonthereceiver,oneeyeonthewaterfallandbothhandsonthewhistleImultitaskedmerrily.IhadnotheardallthatmuchOliviadigitalmodeinuseon160meters(orontheotherbands)soIoften

foundthatcallingCQinthatmodewasmoreeffectivethanjustlisteningforactivity.AsIwassloggingmyway throughO’Carolan’sConcerto for the second time,whistling likeapiperon fire, theauto-CQalreadyhadfinishedfivecalls.SofarIhadnotheardthecacophonyoftonessignifyinganOliviasignalornoticedanythingatall inthewaterfallwindow.ItwasatthismomentthatIenteredtheworldoftheparanormal.I chanced to glance at the text box that displayed received (decoded) text and I saw characters

appearing.Mycall letters appearedas if aghostlypresencewas typing themandansweringmyCQ. Iscreechedtoahaltonmywhistling,immediatelydisabledtheauto-CQandturnedupthereceivervolume.Withthevolumeallthewayup,allIcoulddiscernwastheusualS8hissandstatictypicalofnightson160meters.Thewaterfallstilldidnotshowanysignalatall–butthecharacterskeptappearing!Whatwasgoingonhere?Wasittimetoshuttherigoffandconsiderbedrestandrehabilitation?WasitabadpieceofmeatoranuncookedportionofpotatoIhadfordinnerthatwascausinghallucinations?OrshouldIattempttoanswertheghostlycall?

There’sNo0forSignalStrength

Well,IamahamfirstandforemostsoIcautiouslyclickedonthetransmitbuttonandbegantotapout

my reply – only hesitatingwhen I had to consider justwhat I should give as a signal report. I finallybangedouta519RST(Readability,SignalStrength,Tone)report(onlybecausethereisnozeroforsignalstrength)andsentitbacktomyghostlyfriendtoseewhatwouldhappennext.Well,wewentbackandforthforseveraltransmissionsasweexchangedalltheusualinformationand

thenweendedtheQSOpassingafriendly73toeachother.MyghostlyfriendappearedtobearealhaminTexasandcheckedoutokayonthewebsitewww.QRZ.com.Mysanitywaspreservedandapparentlyintact (mywifedoesn’t totallyagreeon thispoint), though Iwas still slightlyconfusedand filledwithwondermentbywhathadjusttranspired!SincethatdayIhavehadseveralmoreofwhatIrefertoas“Ghost”QSOsusingtheOliviamodeand

havedonealittleonlineresearchtoreassuremyselfthatthisisnotallthatuncommon.ForthepreviousthreeandahalfyearsIhadmostlyoperatedonPSK31(adigitalmodeusingphaseshiftkeyingat31.25bits/sec)andalittleMFSK16(MultiFrequencyShiftKeying;adigitalmodeusing16tones)andyetIhadnever experienced this type of ghostly phenomenon with either of these excellent digital modes.ApparentlyOliviaisoneofthefewmodesthatcanactuallydecodesignalsthatareatorbelowthenoiselevel.ThatiswhyIneverusethesquelchwiththismodebecauseitcouldcutoffsignalsbelowthenoisefloorthatwouldotherwisebedecoded.The Internet resource Wikipedia.org says, “Olivia MFSK is an Amateur Radio teletype protocol

developedbyPawelJalocha,SP9VRC,inlate2003toworkindifficult(lowsignal-to-noiseratioplusmultipathpropagation)conditionsonshortwavebands.Asignalcanstillbeproperlycopiedwhenit isburied10dBbelowthenoisefloor(iewhentheamplitudeofthenoiseisslightlyoverthreetimesthatofthe signal).” TheWikipedia entry includes several paragraphs describing the technical details of themode.1Now,IamneitheratechnicalwhiznoranexpertinanyfieldbutIfoundmyselfsmitten.Idon’thavea

giant towerwithhumongousbeams, runhighpoweroreven liveatagreatham location,butOlivia inparticularhasmadeitpossibleformetochaseDXandhavequalityragchewslikenoothermodeIhaveeverused.IthasreallyignitedmyactivitylevelandfunfactortoheightsthatrivalmyearlyNovicedaysandlaterDXchasingwhenIdidhaveabigtowerandmassiveantennas.

LetMeIntroduceYou

Oliviamodecanbesettovariousformatsthatarelabeledusingtheparticularformat’sbandwidthandnumberoftones.Bandwidthsof125,250,500,1000and2000Hzaretypical.Thenumberoftonescanbesetanywherefrom4to256dependinguponthepropagationconditions.Differentcombinationsoftonesandbandwidthsprovideforslowerorfastertransmissionrates.Commonlyusedformatsare125/4(125Hzbandwidthusing4tones),250/8,500/16,500/8and1000/32.The500/8formatseemsmostpopularatthismoment,thoughIhavehadseveralQSOsonthe125/4and250/8.The1000/32formatseemstobepopularon20meters.Eachof theOlivia formats has advantages anddisadvantages.Obviously, the bandwidth differences

make themore narrow formats attractive because theywill fit in available open spectrum spacemoreeasily.They alsowill likely get through slightly better since all the power of the transmitted signal isconcentratedinasmallerbandwidth–muchthewayCWgetsthroughbetterthanwidephonesignals.

The speed ofOlivia is an issue also.Olivia is generally not as fast asPSK31orMFSK16.Olivia500/16sendstextatapproximately20wpm.The500/8formatspeedsthatuptonearly30wpm.Fewertonesresultsinmorespeedwhilelessbandwidthresultsinslowerspeed.Olivia1000/8and2000/8areoftenusedbyMilitaryAuxiliaryRadioSystem(MARS)trafficnetsbecausetheseformatsarefairlyfast,accurateandget throughwhen theMT63mode(adigitalmodeusing64 tonesphase-shift-keyed ina1kHzbandwidth)fails.MostofthisinformationandmorepertainingtoOliviaareavailableattheHFLinkandDXZonewebsites.2,3ManyhamsfindOliviaslowerthantheylikeandprefertouseothermodes,whilemanyothersfindthe

accuracyandabilitytogetthroughanacceptabletrade-off.Also,manyofus,includingmyself,arenotfasttypists and actually find “slower” to be a positive attribute and allows formore comfortable overalloperation.

Anotheradvantagetothemodeisthatit’snotquiteascriticalforittobetunedexactlyonfrequencyasit is with PSK,MFSK andmany othermodes. If you click on thewaterfall with yourmouse and theindicatordoesn’tgetexactlyonthesignalitmaystilldecodeproperly.MostimplementationsofOliviaaresettosearchforsignalstoeithersideofyourcenterfrequencybyafixedpercentageofyoursignal’swidth.

PioneersWanted

Theactivity levelofOliviacanbedescribedassomewhatsparse,especiallycompared toPSKandCW.That is partly explainedby the fact that only a fewprograms supportOlivia at this time and thatOliviahasnotbeenaroundquiteaslongasotherestablishedmodes.MixW(newerversions),MultiPSK,HamRadioDeluxe’sDM780(latestBetaversions)4andOliviaMFSKsupportOliviaoperationandareavailable forWindows-based computers, while the Fldigi (v3) program is available for Linux andWindowsXP/Vista.There are a few other things worthmentioning about Olivia. Since it does incorporate some error

correcting,itisnottotallya“realtime”mode.Itisessentiallyarealtimemodeinthesensethatyoudonot“connect”toastationanditisnotduplex-orbulletin-board(BBS)typeoperation.LikePSK,yougobackandforthinatypicalhamQSOfashion.Thedifferenceiswhenyouclickonthe

waterfallofaPSKsignalitstartsdecodingveryquickly.WhenyoudothesameonanOliviasignalitmaytake3to6secondsbeforeitstartsdecoding.Theoppositehappensattheendofatransmission.Whenthestationyouarelisteningtostopstransmitting–yourOliviasoftwareprogramwillcontinuetodecodeforthreetosixseconds.Typicallythatwillresultinasixto12secondgapwhenpassingtransmissionsbackandforth.Thisvariesdependingontheformatandthesoftwareimplementationintheprogramyouareusing.I

seelessofagapusingFldigithanwithDM780forinstance.Whatthismeansisthatwhenyouclickonasignalifyoudon’tseeanythingrightaway–bepatient!Ittakesafewseconds.Whenyousenditbacktotheotherstation–again,bepatient.Itmaybeafewsecondsbeforeyoustarttoseehisprintoutorevenhearhim.

TheQSOisontheCallingFrequency

AnotheraspectofOliviaoperation that isslightlydifferent frommostotherdigitalmodes isa loosevoluntarychannelizationofthefrequenciesusedbymanyoperators.Sinceitispossibletocopysignalsthatyoucannothearorthatyoumightnotseeonthewaterfall,itmakessensetousespecificdesignatedfrequenciesforcallingandmeetingotherstations.Otherwise,ifyoujusttunedallovertheplacelookingorlisteningforanOliviasignalyoucouldmissalotofstations.A few of the popular frequencies are 14.107.50MHz (20 meter calling frequency 1000/32 format

generally),7072.50MHz(40metercallingfrequency500/250/125Hzbandwidthformatsgenerally)and10.133.65 MHz (30 meter calling frequency 500/250/125 Hz bandwidth formats generally). Thesefrequencies are dial settings – meaning the frequency that your transceiver would display on uppersideband.Forthe500/250/125Hzbandwidthformatsthewaterfallposition(centermarker)shouldbesetfor750Hz.Onthe1000Hzbandwidthformatthewaterfallpositionshouldbesetat1000Hz,andwiththe2000Hzbandwidthformatitwouldbesetat1500Hz.These “channels” and settings are not cast in stone and are certainly notmandatory or used by all

Olivia stations but they are useful especially to help facilitate weak signal QSOs. For a much morecompletesetofvoluntaryfrequenciesseethechartsattheHFLinkwebsite.

BetterThanCW?

Aftera fullyearofoperatingOliviaIhavehad650QSOswith45statesand21countriesandhavefound it to bemore reliable andmore fun than any othermode that I have ever used on ham radio –including CW. It gets through noise (QRM), static (QRN) and fading (QSB) better than most and isexcellent forDXing, ragchewingandevenVHFweaksignalQSOs.ThefasterOlivia formatsareveryusefulforhandlingmessagetraffic.Theonlyplacewhereitfailstoshineasbrightlyisduringcontests.WithmanyoftheOliviaformatsbeingslowerandwiththe“notquite100%”realtimequality(fourtosixseconddelay)itisprobablynotwellsuitedforcontesting.Sointheend,itturnsoutthatareallygreatcommunicationsmodeandnotghostswereresponsiblefor

myextremelyweakand spookyQSOs. Iwillput awaymyghostbusting tools,discard thebooksabout

Area51andfireuptherigtoseeifIcanscareupsomemoreOliviaactivity!GiveitatryanddiscoverthemagicandmystiqueofOlivia!

~GaryL.Robinson,WB8ROL,wasfirstlicensedin1963asWN8GIGattheageof13andobtainedhisExtraclasslicenseinthemid1980s.Heissemi-retiredandlivinginasmalltowninruralOhiowithhisspouseNancy.Duringhisactiveworkyearsheworemanyhats–includingCorrectionsOfficerfor14years,computertechnicianandC,C++andC#programmer.Currentlyhefocusesonhisfiveloves– ham radio (digital, especially Olivia, DominoEX FEC and THOR modes), computers andprogramming(primarilybutnotexclusivelyonLinux),playingIrishwhistles,fivecatsandhiswife.AnARRL member, Gary can be contacted atwb8rol@arrl.net or look for him lurking in the digitalsubbandsof160metersthrough70cm.

Notes1http://en.wikipedia.org/wiki/Olivia_MFSK2http://hflink.com/olivia3www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=120124http://hrd.ham-radio.ch

Appendix

ReverseBeacons

SteveFord,WB8IMY

Here in the US, the Federal Communications Commission allows amateurs to establish unattendedbeacon stations within various frequency ranges beginning at 28.200 MHz. If you take a quick spinthroughthebeaconsub-bandon10meters,forinstance,you’lllikelyheartheMorsecodeIDsofseveralbeacons,assumingthebandisopen.Reversebeaconsturnthetraditionalbeaconconceptupsidedown.In the land of reverse beacons, there are no unattended transmitting stations, although theremay be

plenty of unattended listening stations. These listening stationsmonitor the bands for CW and digitalsignals. The signals may be from stations engaged in conversations, or from stations calling CQ.Wheneveralisteningstationdecodesacallsign,itnotesthefrequency,timeandoccasionallythesignalstrengthandthenforwardstheinformationautomaticallytoawebsiteforeveryonetosee.

TheReverseBeaconNetwork (RBN)maintainedbyPeteSmith,N4ZR,andFelipeCeglia,PY1NB,dependsonvolunteerlisteningstationsthatuseCWSkimmersoftwaredevelopedbyAlexShovkoplyas,VE3NEA,tocombtheHFbandsforCWactivity.You’llfindtheRBNatwww.reversebeacon.net.Another network, and one ofmy personal favorites, is PSKReportermaintained by PhilGladstone,

N1DQ,athttp://pskreporter.info.Don’tletthenameofthesitefoolyou.ThisreversebeaconnetworkisaboutmuchmorethanPSK.Phil’ssiteaggregatesreceptionreportsofmanydifferentkindsofmodesfromCW to JT65 and displays the results on a near-real-timemap. There are dozens of listening stationscontributingreportstoPSKReporteratanygivenmoment.

IenjoyoperatingJT65ontheHFbandsanduseJT65-HFsoftwarebyJoeLarge,W6CQZ.Itisutterlyfascinating to trydifferent antennasorpower levels and see the resultsonPSKReporter. I canmakeacontactorcallCQandwithin60secondsI’llseereportsonthenetwork.Aglanceat themaptellsmewhichstationsheardmeandwheretheyarelocated.WSPRnetisyetanothertakeonthesameidea,butthisnetworkisbuiltaroundstationsusingK1JT’s

MEPT-JT mode at very low power levels. The reporting website at http://wsprnet.org/drupal/ alsooffersaninformativemapdisplay.

Rememberthatyoudon’thavetobesittingatyourradiotocontributereportstoanyofthesenetworks.You aren’t transmitting; you are simply listening. All you need is an Internet connection and theappropriate software depending onwhich network youwish to join. I routinely activate the reportingfunctioninJT65-HF,parkmyrigonaJT65frequency(suchas14.076MHz)andwalkawayforhours.While I’mout runningerrandsorputteringaround theyard, I’malso renderinga service tomy fellowhams.Suchadeal!

Appendix

DigitalVOXSoundCardInterface

TheShortScoopHere’saninterfacethatwillgetyouontheairwithPSK31andotherdigitalmodesregardlessofthetypeofcomputeryouareusing–noserialorUSBcablerequired!

Howard“Skip”Teller,KH6TY

Mostsoundcardinterfacesarepoweredeitherbyavoltagefromthecomputerserialport,byavoltagetaken from the computer accessory port or microphone port, or by a “wall wart” ac adapter. If thecomputerhasnoserialport,andmostcomputersthesedayshaveUSBportsinsteadofserialports,itisalso necessary to use a USB serial adapter to generate a virtual serial port that the communicationssoftwarecanuseforpush-to-talkoperation.Itwouldbemoreconvenientifnodcvoltagewereneededtopowertheinterface,andalsoifnoserial

portorUSBserialadapterwereneeded,soIwantedtofindawaytoeliminateboththeneedforaserialportorUSBserialadapterandadcvoltage.Ithenrealizedthatcomputersoundcardshaveevolvedfromhavingbothahighlevelspeakeroutputjackandaline-levelaudiooutputjack,tousuallyhavingjustanearphone/headphonejackandamicrophonejack.Measuringthemaximumaudiooutputlevelofthisjackonseveralcomputers,andalsoonanexternalsoundcard,suchas“USBsoundadapters”commonlysoldtoprovidemicrophoneandearphonejacksviaaUSBconnector,Ifoundthatitwasgenerallyaround2.5Vpeak-to-peak–notenoughtopoweraswitchingtransistorinaninterface.

Byconnecting theearphone/headphoneoutput to thecenter tapofa600:600Ωisolation transformer,however, thatvoltage isdoubledacross the full secondarywindingof the isolation transformer to5Vpeak-to-peak–enoughtorectifyandpoweratransistorswitchforpush-to-talkswitching.Sinceallthisoccursat thesecondarywindingof thetransformer, thetransformerstill isolatesthecomputerearphoneoutputandgroundfromthetransceiveritself,therebypreventinganyhumorgroundloopsfromdisturbingthetransmitorreceiveaudio.Byusinganotherisolationtransformerfor thereceiveaudio, thecomputer is totallydc-isolatedfrom

thetransceiver,bothontheaudioinputlinesfortransmit,thereceiveaudiooutputlineforreceive,andthepush-to-talkswitchinglinefortransmit/receiveswitching.TheschematicdiagraminFigure1showshowthisisolationisprovidedbythetransformers.

HowItWorks

SeeFigure1.Sound-card-baseddigitalcommunicationssoftware,suchasDigiPan,generatesaWAVaudiosignalwhenplacedinthetransmitmode.ThisWAVaudiocontainsthemodulationthatyouusetocommunicatewithondigitalmodes,suchasPSK31andothers,andisusedtomodulatethetransceiverinthesameway thatyoumodulate the transceiveraudiowith themicrophonewhenoperatingSSB.SincethisWAV audio comes out of the earphone or speaker jack of the computer, that jack is connected toisolation transformer T1, but only between one side of the primarywinding and the center tap of theprimarywinding.When this audio is coupled across the transformer to the full secondarywinding, itappearsat twice thevalue that ispresentbetween theprimarycenter tapandeitherendof theprimarywinding,becausetheturnsratioofthetransformerinthatcaseisnolonger1:1,but1:2.TheWAVaudio is then used tomodulate the transceiver through the data, accessory ormicrophone

jacksfordigitaloperating.TheaudiolevelisadjustedbymeansofpotentiometerVR1.In order to switch the transceiver from receive to transmit, this same double-value ac voltage is

appliedtocapacitorC1andresistorR1,whichisolatethetransformeraudiofromtheswitchingactionofthe following voltage doubler circuit, D1 and D2. These diodes form a classic dc voltage doublerrectifiercircuit,whichconductsonbothpositiveandnegativecyclesoftheWAVaudio.C2thenchargesuptothepeakvalueof theacvoltageandholdsthatchargelongenoughtodrivethebaseofswitchingtransistorQ1, through current limiting resistorR2, causing the collector ofQ1 to saturate andpull thepush-to-talkpinofthetransceivertoground.Q1getsitsoperatingcollectorvoltagefromthepush-to-talkcircuitinthetransceiver,whichmustbedesigned,asalmostalltransceiversarethesedays,foran“opencollector”switchfortransmit/receiveswitching.

Transformer T2 is used to isolate the receive audio to the computer from the transceiver, and theprimaryisconnectedtothecomputermicrophoneinput.ThereceiveaudiooutputvoltageisfedfromthetransceiverthroughanL-padconsistingofR4andR3,attenuatingthehighaudiooutputofthetransceiverdatajack,orearphonejack,toasuitablelevelforthemicrophoneinputofthecomputer.Itisthisinputtothemicrophoneofthecomputerthatcreatesthe“waterfall”displayofthetypicaldigitalcommunicationsprogram that alsodecodes theWAVaudiobeing transmittedby theother station into characters on thescreen.ResistorsR4andR3canbeexchangedinpositionifthecomputeraudioinputrequiresahigheraudiolevelfromthetransceiver.

AdjustingtheTransmitLevel

Beforeconnectingtheaudiocables,youshouldbeabletoheartheWAVaudiointhecomputerspeakerswhenthesoftwareisinthetransmitmode.Pluginbothcablesbetweenthecomputerandtransceiver.Withthesoftwarewaterfallcursoraround1500Hzandthesoftwareintransmit,raise theaudiooutput leveluntil the transceiver switches into transmit.Onceagain, if the softwareyouareusingdoesn’toffer themeanstomakethisadjustmentyou’llneedtoaccesstheaudiolevelswithinWindowsControlPanel.Whenthe transceiverswitches into transmit, increase theaudiooutput levelaboutonemorenotch to

ensure there is enoughaudio forpush-to-talk to consistently activate.Adjust the transceiverRFpowercontrolformaximum,orifusingthemicrophonejackonthetransceiver,tothenormalpositionforSSBphoneoperation.NowadjustVR1untiltheRFoutputofthetransceiverisabout30%ofratedmaximumpower.Itshouldnotbenecessarytomakethisadjustmentagain.Justraisetheaudiooutputlevelcontroltoobtainalittlemoreoutputpowerifdesired,butat30%power,youshouldautomaticallyhaveacleanPSK31signal.After setting theRFpower level, place thewiredcircuitboard into the enclosure and snap the two

halvestogether.Thiscompletestheassemblyandadjustmentoftheinterface.Ifyoufinditnecessarytoadjust the interface very often, it might be convenient to drill a small hole in line with VR1 so ascrewdriver can be inserted into the enclosure to adjust VR1. In most cases, however, it should bepossibletojustsetVR1andleaveitalone,doingallthefinepowersettingadjustmentswiththesoftwareaudiolevelcontrols.NeartheextremeedgesoftheIFpassband,theaudiooutputofthetransceivermaydecreasebecauseoftheshapeoftheIFfilter,soitmaybenecessarytoincreasetheaudiooutputleveltomaintainpush-to-talkaction.Remember to recheck thepoweroutputwhen retuning to thecenterof thepassband.ThedigitalVOX interfaceworkswellwith all digitalmodes such asPSK31 andAFSKRTTY,but

doesnotworkcorrectlywithsoundcardCWorHellschreiber.Ifyouintendtooperatethosemodes,theClassicSoundCardInterfacedescribedonpage37oftheJuly2010QST isabetterchoicebecauseitsserial port switching keeps the transceiver in transmit until the software returns it to receive. It is notdependentupontheaudiotonesbeingpresenttokeepitintransmit.

~Howard“Skip”Teller,KH6TY,isanARRLmemberandwasfirstlicensedin1954.HereceivedhiscommercialFirstClassRadiotelephonelicensein1959andworkedhiswaythroughcollegeaschiefengineerofseveralradiostations.HeholdsaBSdegreeinelectricalengineeringfromtheUniversityofSouthCarolinaandisretiredfromrunningafactoryinTaiwan,wherehemanufacturedtheweather-alertradioheoriginatedin1974andisstillsoldbyRadioShackandmanyothercompaniesnow.Skipenjoysdevelopingdigitalsoftware,suchasDigiPanandNBEMS,anddesigningVHF/UHFantennas.Heiscurrentlystudyingthepotentialofworking432MHzDXusingtheContestiadigitalmode.YoucancontactSkipat335PlantationViewLn,MtPleasant,SC29464;skipteller@gmail.com.