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Re: 9600 baud challenge (was: Re: tnc-modem Query)



On Mon, 9 Aug 1999, Laura Halliday wrote:

> Rather than forking out major money at the ham radio store, I'd
> like to issue a challenge: what is the cheapest setup people can
> come up with to receive from the 9600 baud satellites? I don't
> care if it's homebrew, or modified commercial gear, or whatever.
> I don't care how ugly it is. Just as long as it's cheap, and
> receives 9600 baud.
> 
> Let's worry about transmitting later. You can't work them if you
> can't hear them...

How about a 70-cm to 10-meter downconverter working into a single chip
Motorola MC3362 (or equivalent) receiver working into a homebrew modem? 
Don't bother using a synthesizer or crystal for the first LO of the
10-meter receiver since the downlink signal's gonna drift due to Doppler.
Wrap some AFC around the receiver to track for Doppler and compensate for
any receiver drift.

The most expensive item: the downconverter (which is something you
shouldn't skimp on anyway)


73, de John, KD2BD

--
-=-=-=-=-=-=-=-=-=-=-=-=- John A. Magliacane, KD2BD -=-=-=-=-=-=-=-=-=-=-=-=-
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