[Elecraft] K3 in a cw pileup - needs work

[Don Wilhelm]

Barry,

I do not believe that is true, and the graphs at 
http://www.cliftonlaboratories.com/elecraft_k3_agc_and_s-meter.htm#AGC_SLP_and_AGC_THR
bear the real facts as well.
Raising the AGC Threshold allows stronger weak signals (less than -100 
dBm for THR=008) NOT to activate the AGC.  Stronger signals will still 
activate AGC.  The Hardware AGC is not changed by the threshold setting.
The result is the range over which the AGC operates, and that is 
different than the dynamic range of the receiver.

The Gain Throttling talk has mostly been with reference to the 
amplification of atmospheric noise rather than the detection of weak 
signals.  While related, I do not think they are the same.

The preamp and attenuator DO translate the receiver dynamic range to a 
higher or lower level - and the hardware AGC trigger point is translated 
as well.  Since the RF Gain is really an IF gain, it does not alter the 
onset of hardware AGC.  Lyle would have to comment on whether the DSP 
AGC is developed before or after the IF gain is applied, I do not know.

73,
Don W3FPR

Barry N1EU wrote:
> If you simply raise AGC Threshold, you will have to lower AF Gain or risk
> overly loud audio from stronger signals.  So what you would effectively be
> doing is translating upwards the K3's dynamic range into higher rf levels. 
> This is NOT good practice - you want to keep the dynamic range operating at
> lower rf levels (thus all the talk of gain throttling).
>
> 73,
> Barry N1EU
>   
>