Wednesday, October 07, 2009

Embarrassing moments in ham radio #1

Steve, GW7AAV's blog post Computational Nostalgia brought back memories of some of the ham radio related things I used to do with the early personal computers. I actually passed my Morse test in 1979 after practising with a morse tutor I wrote in Z80 machine code on a home-built Nascom 1 with 1Kb (yes, that's right, 1024 bytes) of RAM. I've written numerous Morse training programs since then including MorseGen and Morse Machine and I still struggle to go faster than 12wpm!

I wrote a Morse decoder for the Sinclair Spectrum that very occasionally printed out a few correct words from an interference-free S9 signal. And I sort of invented PC sound card software, although the memory of it now causes me some embarrassment.

I had an ERA MicroReader which decoded RTTY and displayed it on a digital readout. I wanted to try contacting the stations I heard, so I wrote a program to generate RTTY "diddles" by sending BEEP commands to the sound card. Except it wasn't a sound card - I don't think they'd been invented in 1986 - it was the PC beeper, an altogether cruder device. I can still remember working an Italian station by holding the mic close to the PC speaker while my program diddled away until it was pointed out to me that the far from sinusoidal audio waveform was causing my signal to appear in several places!

Well, ham radio is supposed to be about self training, and I learned something from that...
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