[TenTec] Argosy I "Thump"

[Dr. Gerald N. Johnson]

On Wed, 2006-08-16 at 18:57 -0700, Shawn Upton wrote:
> That's what I was starting to think, it was to do with
> the speed at which the audio derived AGC could
> respond.  Lately, as I play on 80m, I've been
> wondering what I could do, perhaps disable AGC and
> change the pot from volume to IF gain instead, that
> way I could run just the right amount of gain so as to
> lower band noise and make for more pleasurable
> listening.
> 
> BUT
> 
> Used it last night, and the feller I was talking to
> disappeared.  Have a sked on Wednesday nights, and was
> told that I was drifting around!  Changed rigs and was
> fine on that, and he was plenty louder too.  Not sure
> why, not yet at least: I do have a digital readout,
> separate from the rig, and it did not indicate drift. 
> Doesn't bode well...
> 
> Just when I was thinking I have my CW rig (no
> chattering QSK relay!), I find I have bigger problems
> than noise.
> 
> 
> Shawn Upton, KB1CKT
> 
Backing off on the RF gain (not the IF gain) can minimize the excess
signal power stored in the filter to make the thump. At least that works
in my Corsair II. You need to keep enough gain to handle propagation
fades though and let the AGC take care of those smaller variations.

-- 
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer