Re: [amsat-bb] 56002 EVM and 38k4

[John Melton <John.Melton@xxxxxxx>]

It is possible to modify the g3ruh 9k6 modem to run at different speeds
including 38k4.  See the notes by James at:

 http://www.amsat.org/amsat/articles/g3ruh/109a.txt

Of course you also need the TNC to be able to run the serial link to the
PC at a speed greater than 38k4.

My testing of the 56002 EVM at 38k4 was that it was right on the limits
of the EVM capability and would miss quite a lot of packets.

-- John,  g0orx/n6lyt

On Sat, 2005-02-26 at 04:27, Scott Avery WA6LIE wrote:
> Gentlemen,
> 
> Seeing loopback tests failed, looks like more research is needed.
> It is very suprising that 384K with tracking and Doppler even works on UHF! 
> AFC, tracking etc..
> 
> 73, Scott
> PS... If you are in the Central California Area, ie. Monterey tomorrow, 
> Saturday, join us at the Radiofest!
> www.radiofest.org for more info.
> 
> 73, Scott
> 
> 
> 
> ----- Original Message ----- 
> From: "Mark L. Hammond" <mlhammond@charter.net>
> To: <amsat-bb@amsat.org>
> Sent: Friday, February 25, 2005 7:28 PM
> Subject: [amsat-bb] 56002 EVM and 38k4
> 
> 
> > Well, so much for that idea---here are some interesting results using a 
> > loop back test (TX radio port 1 and RX radio port 2)
> >
> > If I set the 38k4 code to:
> >
> > 9k6 xmit/9k6 rcv, the loop back works fine
> > 19k2 xmit/19k2 rcv, the loop back does NOT work at all
> > 28k8 xmit/28k8 rcv, the loop back works almost works; I connect to myself, 
> > but nothing else
> > 38k4 xmit/38k4 rcv, the loop back does NOT work at all
> >
> > So much for generating wave files!
> >
> > I'll have to look closer at the Sprint-2 to see if it will xmit 38k4...
> >
> > 73,
> >
> > Mark N8MH
> >
> > >//Now that I have two confirmed/working TNCs (okay, one is a DSP ;) for 
> > >38k4, I think I will try to get my TAPR DSP56002 EVM unit outputting 38k4 
> > >data (presumeable it can, by just a quick edit in the code so it xmits 
> > >38k4 instead of 9k6).  So, essentially EVM 38k4 OUT --> Paccomm 38k4 IN 
> > >is the test.  If I can get that working, then I can begin an attempt to 
> > >record (and playback) some 38k4 packet audio files for Doug (and others 
> > >that might be interested...), as well as experiment a bit with the 
> > >PCR-1000 in my shack.
> > >
> > >Looks like a fun project for this weekend!!
> > >
> > >73,
> > >
> > >Mark N8MH
> >
> >
> > Mark L. Hammond  [N8MH]
> > ----
> > Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> > Not an AMSAT member? Join now to support the amateur satellite program!
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> ----
> Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> Not an AMSAT member? Join now to support the amateur satellite program!
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-- 
John Melton <John.Melton@Sun.COM>
Sun Microsystems, IT CTO
----
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