[TenTec] Re: Al Gavenas' position on Front-End atenuation

Wed, 09 Apr 2003 19:37:27 -0700

Boy did I ever olen up a can of worms.  If you are trying to pull in a sig
that is down in the mud, you need every trick in the book and then some.
Perhaps I went a little overboard on running the audio wide open.  The 
Pegasus seems at times that it could use a little more audio.  I don't 
think tha the audio out from the Peggy is ever going to make your chest 
heave like the Audio at a rock concert.  Anyway the point I was trying to 
make is that
for a reasonable strong sig using the RF gain control does seem to help.
The article I was referring to is the part two of "How to Maximize your 
Receiver's Effective Selectivity" by W4GEY in the March 2001 QST.
Please note, I do have a hearing loss and what works for me may not work
for the next guy with perfect hearing.  Anyway I do want to thank one and
all for the interest.

73
Al Gavenas  WA6IQD
>>>> [email protected] <<<<

On Wed, 09 Apr 2003 18:17:24 -0400, Allan Henry Kaplan 
<[email protected]> wrote:

> The article to which Mr. Gavenas refers was, alas, one of the most
> misinformed and misleading pieces to ever appear in QST!  Sometimes you
> can decrease the effect of atmospheric noise as a distraction to a
> wanted signal by turning down the "RF Gain" or inserting an RF
> atenuator.  The catch is:  That strategy works only if the desired
> signal is substantially louder than the noise.  If the signal is weak --
> not a whole lot greater than the external noise -- RF attenuation (or
> gain control) will degrade the net signal-to-noise ratio.  If one runs
> the AF gain wide open and controls speaker-blasting with the RF gain, he
> emphasizes the receiver's internal hum and noise with respect to the
> weak signal.  In many cases, the weaker signals simply will not be
> heard!
>
> Running AF gain wide open and riding the RF gain control is just BAD
> ADVICE unless you are in a QSO with pretty loud signals -- KWs across
> town on 75 meters, perhaps.   If you are after DX or QRP that is the
> WRONG way to go.
> 73, Allan, W1AEL.
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