{02-21-13} Comment: Many years have passed since this article was written but it still contains a lot of good information. consider it a primer to get you going. A lot of things have changed in this technology with many new modes becoming available. the best part of it all is that for those who are willing to experiment and play a bit, it cost very little to get into the digital modes. There is no need to buy a fancy new computer of radio to computer interface. This is one area where you can make up your own interface and still have a lot of fun. For those with some of the new radios, it is just a mater of connecting a USB cable between the rig and the computer. Jump in and have fun!
Someday when I have spare time, I will look at doing a re-write but in the mean time here it is as first written in 2000.
Things are moving so very rapidly these days and Amateur Radio has not been left out when it comes to this. If you are not actively using internet, you may not be aware of the advances that have been taking place in both the digital modes and digital application software. Best of all much of the software is available free. Like the sound of that, the favorite Ham word when it comes to getting stuff "FREE"!
What is even better is that to use these new modes will cost you very little! You don’t have to rush out and buy an Multi-mode TNC to use this free software. If you have a computer with a SoundBlaster compatible soundcard you can get on the air. A low end Pentium is preferred but there are some programs that will work on faster 486 machines. The interfacing to your radio is also very simple and cheap! A simple overview, speaker audio from you rig goes to the soundcard input, audio out from the sound card goes to the microphone input of your rig. Using VOX this can have you up and running in several modes. PTT control is a more preferred way to operate and will require a connection from a serial port on your computer to the rig. This will get you on the air. RTTY the old standby can be a good starting mode. One of the best RTTY )soundcard) programs to ever be written is MMTTY, see the link below. Have you heard guys talking about the "DSP audio filter" connected to their rig? We can do that too with your computer! How about test equipment? Read on to learn about the possibilities that await you and your computer.
Lets first start with the digital modes. Most hams have heard of RTTY and Packet. Amtor and Pactor are also more commonly known and some may have heard of a new mode called PSK which was written about in QST.. There are newer commercial mode such as Clover I & II and PactorII that we will leave out of the discussion because they cost money. hi.. We can now add a whole new list of mode to those we already have and many you may not have hear of before. All of the following mode can work with only a computer and soundcard.
ALE – Automatic Link Establishment Protocol.
MT63 – DSP based mode using 64 tones.
MFSK16 – Multi-tone frequency shift keying using 16 tones, with FEC (error correction).
MFSK8 – Multi-tone frequency shift keying slower baud rate, with FEC (error correction).
PSK63F – new mode with little info available.
Throb – Multi-tone frequency shift keying using 9 tones.
Hell – characters displayed in a matrix of dots (like DM printer) an older mode new to HR.
FSK31B – higher baud rate than PSK31 with FEC added.
BPSK – commonly referred to as PSK31 – very narrow band width – great for QRP work.
QPSK – version of PSK31works well in conditions when BPSK fails. – slower throughput.
MTTY – MIN. shift TTY, it's the same as usual RTTY with 22.7 Hz shift (23Hz).
RTTY – old standby Radio teletype – software adds new features, on screen tuning scope, etc.
SSTV – Slow Scan Television – with cheap PC cameras it’s easier than ever.
FAX – various version similar to weather FAX.
Packet – AX25 packet at various baud rates without a TNC.
Amtor – Amateur teleprinting over radio an improved version of RTTY.
Pactor – an improved version of AMTOR that included data compression. 100 & 200 baud.
CW – some of the new software does a remarkable job of copying Morse code.
Now if that is not enough to get you trying new things with your computer or you are happy using SSB or CW, how about adding a DSP filter to your station only using a computer with a soundcard. All you have to do is feed the audio from you rig into the soundcard, load the program and get adjusting filters. No need to pay hundreds of dollars for a dedicated DSP when you already have what you need. Another use for your computer, especially for contesters, is as a memory keyer for CW or a DVR (digital voice recorder) for SSB. There are just so many used for a computer in the ham shack.
Still need more uses for your computer? Ever wished you had some fancy test equipment? Here again there are lots of things you can do with a computer and a soundcard. A few examples I have found, oscilloscope, audio generator, spectrum analyzer, radio propagation simulator, and frequency counter to name a few. To round out the collection you can add DTMF decoders, DTMF generators, FM transmitter signal print identifiers and much more. It is all waiting for you on the internet.
Where do I find this software? Here are some links to get you started. If you don’t have internet, maybe now is the time, other wise check with a friend or your local library.
