The 12 khz IF only moves in 2.5 khz steps. There would be no way to be more
accurate in the sweep display than 2.5 khz. You would end up with a plot of
vertical blocks, each 2.5 khz wide.
Having the jupiter firmware provide real antenna voltage not affected by AGC
seems the best way to go to me.
Carl Moreschi N4PY
Franklinton, North Carolina
n4py@earthlink.net
----- Original Message -----
From: "Mark Erbaugh" <mark@microenh.com>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Wednesday, February 23, 2005 10:59 AM
Subject: Re: [TenTec] Pegasus/Jupe Band Scope Questn
> > It makes sense. When the Jupiter does it's own scan, it's much
> > faster. 2 questions:
> >
> > Does the agc not affect the Jupe in standalone mode scanning?
> >
> > Could a firmware change take care of this?
>
> I asked Gary Barbour at TenTec the same questions a while back.
>
> In sweep mode, the Jupiter firmware does bypass the AGC and it would be
> possible to add that mode (AGC off) as a setting for use with external
> sweeps.
>
> However, I'm considering another alternative. There is a mod to the
Pegasus
> and Jupiter that brings the 12 kHz IF out to the spare jack on the back of
> the radio. This IF is normally fed to a computer soundcard where it is
used
> to decode DRM (digital shortware broadcast) signals. This IF is unaffected
> by the digital AGC in the radio (as it is still in the analog stages of
the
> radio). This signal could be analyzed in the a computer program to provide
a
> sweep. There would have to be some coordination between the analog tuning
> and the signal received, but it should be possible to get a nice sweep
> display. In fact, it should be possible to provide a real time band sweep
> of signals adjacent to the current signal, at least those within the width
> of the 20 kHz roofing filter.
>
> 73,
> Mark
>
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