The most common source of "pumping" is a strong signal inside the roofing 
bandwidth and outside the DSP width.

This would engage the protective hardware AGC, particularly if the preamp is 
engaged.  Particularly on 160, start with the ATT engaged and preamp off. 
It is a rare day when ATT is not the correct setting for 160m.

If you are trying to listen with the width narrowed by DSP and using a wide 
filter, make sure your filter settings correctly turn on the next lowest 
width at the correct point as you narrow the DSP width.

I currently use 2.7, 1.8, .4 and .25.  If there are a lot of loud stations 
in the bandwidth at 2.7 on my setup, reducing my width to 2.0 or 1.9 may get 
them out of the audio, but they are still in the IF until I engage the 1.8 
filter and can "pump" the hardware AGC if they are loud enough or I have 
made them loud by running preamp or not running ATT on 160.

For casual SSB, if it has loud encroachment at 2.7/2.7 I go elsewhere.  For 
contesting or digging in pileups it's 1.8/1.8 and it stays there.

73, Guy.

----- Original Message ----- 
From: "WN3R, Dick" <w...@verizon.net>
To: <w...@arrl.net>; <elecraft@mailman.qth.net>
Sent: Tuesday, April 14, 2009 6:56 AM
Subject: [Elecraft] K-3 Odd problem on 160m (second posting)


>I put up a new 160m dipole and SSB signals sound as if something is pumping
> the AGC while it's in the slow mode.  SSB Stations sound much better with
> Fast AGC.  I have a Dunstar 600 but since I am using the aux ant jack it's
> not used on receive.
>
> Perhaps I should reconfigure to add the Dunstar?  BTW, when listening on 
> the
> K9AY loop, signals sounds much better perhaps normal (no pumping).
>
> Any ideas?
>
> 73, Dick, WN3R
>
> PS I forgot to put K-3 in the subject line.
>
>
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