[Elecraft] Starting values for AGC with MCU 4.51 ???

[Ed Muns]

The full range of SLP values only applies at the lower THR values.  With
THR>8, the lower SLP values are not effective.  That is, for THR>8 there is
a SLP value below which the AGC curve does not change (become steeper).  At
THR=15, SLP values 0-7 all result in about the same effect as SLP=7.  At
THR=20, the AGC curve is essentially the SLP=15 curve for all values of SLP
from 0-15.  The SLP=0 curve is only 1-2 dB higher than SLP=15 at S9+40dB.

THR=20 is very different than AGC=OFF.  With AGC=OFF, the always-on hardware
AGC allows audio levels 20+ dB higher than the least aggressive DSP AGC
(THR=20, SLP=0).  That's why the AF LIMiter function is available ... to
protect the user's ears.

Ed W0YK
 

Drew AF2Z wrote:
> >I don't get the point of THR 20 SLP 0. I assume that is 
> pretty much the 
> >same as just turning off the AGC.

Dave K6LL wrote:
> 
> That is correct for low to moderate signal levels.  At high 
> signal levels, a pretty aggressive agc flattening kicks in, 
> even at slp=0.  This flattening is more comfortable to deal 
> with than the raucous-sounding AF Limiter, which operates 
> only with AGC turned off.