Date: Tue, 30 Mar 1999 21:46:46 -0500
From: Bob 
Newsgroups: rec.video.satellite.tvro
To: Robert Smathers 
Subject: Re: [Home-Sat] Re: ? EMWIN data on SBS6 ???


Demodulating this is simple. What they do is hard shift the 1.065 MHz carrier
for mark or space. No audio, or anything. Bandwidth should be 25 KHz. This is
similar to what is done for POCSAG, etc pagers. In fact, if you go higher, and
lower (1.065 +/-  that is), you'll find alot of paging services, even some
voice. This is THE transponder that crippled the country's pagers  when G4
failed. To demodulate, just clip the "audio" that you hear. Actually, you'll
have to get at the signal in you receiver before any de-emphasis is applied.
What you wind up with is 9600, N,8,1 data - some clear text, alot of graphics.
Just go get WeatherNode, and you're set. I'm sending Rober Smathers a gif of
the circuit - hopefully he'll post it. The demod's on the NOAA / BIG-Z page
are for the GOES birds.

 
Robert Smathers wrote:
> Bill Jones  wrote:
> >From: "Bill Jones" 
> >He said 12.185 GHz, which is KU.  This should be on the high
> >side of transponder 28, which on my Drake with the T1
> >configuration works out to "channel" 32.
> >
> >   I tried tuning to channel 32, and got a weak carrier. I then
> >turned on my FM^2 receiver onto 1.065 MHz, and didn't hear
> >anything, no hint of a subcarrier. (Since he said there was no
> (...)
> >     I'd be interested in whether anyone else can hear any hint
> >of a signal there. The Drake I'm using doesn't have as much
>
> I get a very good data-sounding signal here!   Now to go check
> out the EMWIN page for the schematic for the interface board to
> get the binary stuff.
>
> -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> de fcc sgn, Robert Smathers  (roberts@nmia.com)   Albuquerque, NM USA
> Robert's Satellite TV/Baseball page:   http://www.nmia.com/~roberts/
> Proud owner, 5 TODYWEN(!) and 5 BUD-lites - Albuquerque Intl. Downlinkport
> TVRO Audio Subcarrier/SCPC Guide columnist, MONITORING TIMES Magazine