[FARC] Digital Modes

[Kirk Talbott]

I know a few people in the FARC whom have experimented with the Ham digital modes and I wanted to pass along my experiences with these modes.  I want to say these are great modes especially for the "minimalist" station like my own.  The digital modes I've enjoyed the most so far are PSK31, RTTY, Packet, CW, and Olivia.  

PSK31

I've had the greatest of pleasure operating this mode over the past two years and I can tell you that had it not been for this mode I would have given up on HF for good.  

If you've got a computer, an HF transceiver, and an antenna, all you need is a digital interface and some software and you're ready for PSK31.  My digital interface is the West Mountain Rigblaster Plus and included with the interface is a digital soundcard application CD.  Everything you need to run PSK31, RTTY, and other soundcard applications is on the CD.   Other manufacturers of digital interfaces, such as the Signal Link by Tigertronics, also offer a soundcard application CD.   One caveat, most of the software on these software CD's is too old to run correctly on Windows Vista so be aware of this.  It runs fine on Windows XP and older operating systems however.  

To run PSK31 you don't need a lot of power and you don't need much of an antenna.  My antenna is a HY-Power QRP shortened dipole rated for a maximum of 150 watts.  It is 20 feet long and I have it in a sloper configuration.  This would be a perfect antenna for an attic installation.   In typical application I use between 15 and 35 watts.  If I've got a real strong DX station coming in I really want to make contact with, I'll bump it up to 55 watts.  Beyond that I just have to let him go because if he can't hear me on 55 watts he probably won't hear me at all.   This weekend I worked Scotland, Belgium, Spain, and France on PSK31.  

20 meter PSK31 action can be found on 14.070.15, a calling frequency supposedly, but more realistically the center of the 20 meter PSK31 universe.  Activity goes on here all day and early evening.  Look for most DX action between 6:00 and 9:00 a.m. and 4:00 and 6:00 p.m..  There is also plenty of DX PSK31 action on 40 meters on 7.038.  

RTTY

I use a software package called MMTTY, included on the Rigblaster Plus's software CD.  There is not as much RTTY action on 20 meters as there is PSK31 unless you happen to be a RTTY contester and caught the RTTY contest this weekend.  RTTY can be found on 20 meters on 14.080 to 14.095 typically.   RTTY is a cool mode and very similar to PSK31 in operation.  I just wish the software designers had put some sound effects in the software that would actually make it sound like an old radio teletype machine.  It takes a little more power to make contacts with RTTY, typically 30 to 40 watts I found.  

CW

No computer and digital interface needed to operate this "digital" mode, just a straight key.  I've been working and studying CW for the past 3 months now and have been using a computer program called "Just Learn Morse Code."  The program gives you the dits and dahs in random sequences and you type the letters in at the keyboard as you hear them.  You set the speed and just practice, practice, practice.  This got old after a month or so of doing it every day and I wanted to get on the air.  So I just jumped on in there.    Am not real fast on receiving but can do between 5 and 7 WPM accurately.  I send out CQ's on the straight key and wait for the response.  Then I grab a notepad and pencil and start copying.  I know you're supposed to do this in your head but I'm just not there yet.  I try to do CW every day to stay in practice.   

OLIVIA

This is a new HF digital mode I'm experimenting with.  W3FDK Rolan Clark turned me on to this mode.  Additionally there is an interesting article in the December 2008 issue of QST magazine on Olivia entitled "Olivia, the Magic Mode."   I can do the various formats of Olivia on 20 meters on 14.107.50 as this is supposed to be a calling frequency for Olivia.  The software I use for Olivia is called FLDigi.  FLDigi will also do all the other digital modes like PSK31, RTTY, THROB, THOR, Hellschrieber, MT63, MFSK16, et. al..  Other multi-mode digital soundcard applications will run Olivia such as Ham Radio Deluxe's DM780, MixW, MultiPSK, and others.

I've only made one contact on Olivia on 20 meters, 14.107.50, Olivia 1000/32 format (which means 1000 HZ and 32 tones) and that is W3FDK Rolan Clark.  I check it all the time though, looking for those "GHOST" QSO's.  What does GHOST QSO mean?  Supposedly, according to the QST article, you can receive decoded Olivia messages on your computer screen without seeing any Olivia signal traces on your waterfall or hearing any Olivia signals.  The messages just start appearing on the screen right out of the blue.  I haven't had this happen yet, all I receive is garbage characters, but I'm still trying.  

PACKET

You need a computer with a serial port or a USB/Serial converter cable and driver, a Packet TNC, and a VHF radio that is equipped to do Packet.   You don't have to use a digital soundcard application but you can.  You could use Windows HyperTerminal on Windows XP and older operating systems.   Some Hams use MixW, Airmail, and other multi-mode digital soundcard applications to do Packet.  Right now I use Airmail.  Essentially what you're using your computer for in Packet is a computer terminal.  Remember those in the old computer mainframe days?  Windows HyperTerminal makes your PC a computer terminal.  The multi-mode soundcard applications usually have a "DUMB TERMINAL" mode which does the same thing.  

I can't profess to know exactly how Packet works, other than to say simply that you physically connect by radio to another Packet station's TNC via your TNC.  Once connected you type messages to and receive messages from the connected station.  If the connected station's TNC is equipped with a PBBS (a personal mailbox) you can send an "E-mail" message or bulletin to that station.   

Packet is a cool mode I think.  It's old and a little quirky making it especially appealing to me, and it's a command line type of interface;  you enter a command and wait for a response, no GUI's here!   It's not particularly fast, 1200 baud, but it is accurate and VHF makes it very reliable.  We have a local Packet node here in Frederick, FDK, on 145.75 and hold a Packet "net" and ragchew on Saturday nights at 9:00 p.m..   If you've got access to an old TNC, give Packet a try you may like it.  

If you have a "minimalist" HF station and antenna system, are frustrated with the poor band conditions, then HF digital soundcard applications are the way to go.  You'll be doing DX every day guaranteed and for the purist it is still radio! 

73
KB3ONM
Kirk  

  

   

  

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