TenTec
[Top] [All Lists]

Mod For popping & AGC on Argosy

To: <tentec@contesting.com>
Subject: Mod For popping & AGC on Argosy
From: n4lq@iglou.com (Steve Ellington)
Date: Sat, 15 Jun 1996 10:28:55 -0400 (EDT)
Questions on this mod.

1. Since I don't have the diagram nor the Argosy, what is the function of
that capacitor?

2. Does it in any way affect the recovery time of the receiver? Could the
reason for less popping be because it takes longer to recover thus slowing
the qsk? 

I'm working on the same symptom with the Omni 6. Although there are
several cures, all so far have slowed the super fast qsk which us cw nuts
don't want to do. Thusfar, it seems that the popping originates in the
9mhz IF stage and is due to a mixing of the T voltage with the IF signal
in the crystal filters. Replacing the filter with a capacitor totally
eliminates all popping and of course all selectivity (brilliant eh?).

I've tried using capacitors to block the dc to no avail. Next, I shall try
totally isolating the filter from both the T signal and ground. That
T signal is a square wave, rich in harmonics of course. Combine that with
your puney little 9mc IF signal in a tight crystal filter then amplify it
about 50,000 times and no telling what you're gonna wind up with! It
reminds me of my cat when the vacuum cleaner is fired up. He heads for the
pet door full tilt and POPS outside with his hair on end. 


> Change C40 on the audio/IF board from 1 Mfd to a 10 Mfd will stop the
> popping when You return to Receive, Your ears will love it. This takes
> about 10 to 15 minutes.
> 

Steve Ellington N4LQ@IGLOU.COM  Louisville, Ky 


<Prev in Thread] Current Thread [Next in Thread>