Mebart wrote:

OK, I can see it working better in principle, but, without software
writing, how do I do it???

I've never seen a PSK modem chip. I had a tough time finding an MSK
chip! It seems that software is the only presently accepted way to
create a psk decoder. I have googled for PSK MODEM, and found mentions
of it, but I cannot find a hardware solution.

Do you know of a chip that does it (public domain)?

Thanks.

Art



Without software, no. When I built the radio for my thesis I started
with an analog demodulator which occupied a 4.5x6 inch prototyping board
-- I think it had 6-12 chips on it, and it had problems with thermal
stability which is why the final version of the radio used a processor
for the demodulation.

I'm eyeing my thesis, and my brand-new scanner. I keep thinking "36
pages? NO!". If I get the spare time I'll scan this in but right now I
have a shortage on both time and round tuits.

You indicated on another one of your postings that you had found a
suitable FSK chip -- this will work for you, but with far more noise
sensitivity. But: if you started with that chip you could get a working
device _now_; later on when you got all of the other bugs worked out you
could circle around to the detector and upgrade it to something better.

What's this for, by the way?

--
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Tim Wescott
Wescott Design Services
http://www.wescottdesign.com