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Old August 20th 07, 08:17 PM posted to rec.radio.amateur.antenna
Jim Lux Jim Lux is offline
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First recorded activity by RadioBanter: Mar 2007
Posts: 801
Default Practical HF Digital Voice

Bob Bob wrote:
Isn't half the fun of HF using ones brain as an organic processor to
pull words out of noisy signals? grin

Seriously I always wondered why something like PSKnn became so popular
when with a bit more code writing on your average PC might have yielded
a viable digital voice circuit. Maybe your average ham doesn't want to
say much, only caring to exchange RST's for a card! This is actually
what deters me from PSK31, most seem to only want a limited contact..

Does anyone know of a sound card/PC system that does digital voice over
SSB bandwidths? I note the comment about group delay and other problems
using amatuer transceiver equipment. Could not your rigs characteristics
be mapped by a "known" station to reduce this problem.


It's certainly possible, but there's a fundamental problem.. the people
who know how to do it are interested in other things. There are a
variety of digital voice modems available (e.g. the AOR box), but the
algorithms are either uninteresting to a would-be experimenter or are
bound in some form of intellectual property protection (e.g. one could
graft a LPC10E vocoder at 2.4 kbps into Pactor3, but why?)



Since we are on the topic, has anyone used PSK31 mobile/moving? Are
there phase shift issues to be allowed for due to the physical movement
of the station. Probably more of an issue on VHF than HF.. Looking to do
some slow PSK/GPS stuff from the car..



I know some people have tinkered with something like this for a form of
HF APRS.. a bit of googling might turn up something.

Cheers Bob VK2YQA


John Smith I wrote:

Even the arrl (Angry Retarded Radio Lizards?) sees the writing on the
wall ...