[TenTec] Pegasus, old and young dudes

[Steve Ellington]

You are perfectly normal Gary. The Pegasus has 2 stages of filtering. First
the IF filter which is a crystal filter about 6khz wide and then the DSP
filter which is variable. The IF amplifier has it's own AGC loop. Strong
signals falling within the 6khz passband will activate this AGC and reduce
the gain of your IF amplifier. If it weren't for the DSP, the radio would be
like using grandma's console radio! Now the DSP can narrow down things just
fine and it's AGC works very smoothly so you don't hear those big bad
signals outside of it's narrow passband BUT,,,, The IF's AGC will still
reduce your IF amp's gain and this can easily kill the desired signal. You
end up with those strong signals 3khz away causing QRM in the form of
clicking, pumping, swishing or fading and it's all because of the wide IF
filter. Your only hope is to attenuate everything using the attenuator or RF
gain but that also attenuates the desired signal.

Why didn't they put a narrow filter in the IF amplifier, you ask? Easy.
Crystal filters are expensive, the DSP wouldn't have anything to do and you
wouldn't have anything to play with.

Steve
N4LQ
----- Original Message -----
From: "Gary Bernard" <W0CKI@netzero.com>
To: "Ten Tec" <Tentec@contesting.com>
Sent: Sunday, April 02, 2000 12:14 AM
Subject: [TenTec] Pegasus, old and young dudes


>
> I have had my Peg since Nov, 1999 and for the most part am very satisfied.
> However, it seems that the receive selectivity has deteriorated. The radio
> just doesn't handle the old dreaded " adjacent channel interference".
Well,
> the question is, is it me, or the Peg? I have another rig, an Icom 746,
and
> it doesn't have the same problem. When I received the Peg, I was really
> happy with the performance, I have more than a few years experience, old
> dude as my would kids say, but for some reason it seems that it has been
far
> more susceptible to overload from nearby big signals even when I squeeze
the
> filters down. Anyone else, young and old dudes included out there
experience
> the same?
>  Regards, Gary, W0CKI

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