[aprssig] REF: 9600 Doppler Solution?

Matthew Stennett wa4tkg at yahoo.com
Wed Aug 31 10:32:06 EDT 2005


Why did this Fantastic Feat NOT include a 144MHz 
transponder?
I have nothing for 440MHz, no place to put up another 
antenna, and NOW I find out I need to REWIRE / (wire
up
another) Patch cord for the TNC.
Great.
Oh well, I've learned about the new PCSAT replacement 
this morning anyway.

--- Wes Johnston <aprs at kd4rdb.com> wrote:

> One of the problems with receiving PSAT2 9k6 on 70cm
> is the wider
> doppler shift.  It just occurred to me that with the
> use of AGWPE
> (probably mixw32 also), you can setup two sound
> cards in a PC, giving 4
> channels of audio to decode.  Just program each
> sound card input to be a
> 9k6 modem and wire each to a FM receiver tuned to a
> slightly different
> frequency.  Let's say we tune radio #1 437.970 MHZ ,
> radio #2 437.975
> and radio #3 437.980 all at a single site.  The PC
> will try it's best to
> decode signals rx'ed on all 3 modems.  Perhaps when
> the doppler shift is
> 3khz, it'll decode on two of the three modems.  This
> also still leaves a
> 4th audio channel open to be a 1k2 receiver too.
> 
> We're using a setup like this at the NWS office in
> Columbia SC to
> passively monitor 3 voice repeaters for mic-e data.
> 
> Wes
> 
> _______________________________________________
> aprssig mailing list
> aprssig at lists.tapr.org
>
https://lists.tapr.org/cgi-bin/mailman/listinfo/aprssig
> 


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