[Elecraft] Noisy K-3 Receiver

[Paul Christensen]

> CONFIG: AGC THR may be set too high.  Try a lower setting.

I agree with Bill.  He may also want to experiment with other AGC settings 
like AGC-F, AGC-S, AGC SLP and AGC HLD and AGC DCY.

I found exactly what was described until I changed the AGC threshold/slope 
and equally important, the AGC recovery times to less aggressive values.   I 
suspect that aggressive AGC values (even in default) may be causing the 
perceived increase in noise.

He may want to prove to himself that the K3 is quite listenable with 
substantial audio dynamic range by changing to less aggressive AGC values. 
Then, increase accordingly.  The default values are specified in the owner's 
manual so there's always the ability to re-set values if originals are 
forgotten.  My AGC recovery times are set for minimum and for me, that's 
adequate, even under the fast setting.

On some professional DSP-based audio processors, manufacturers have taken 
all the processing values, combined them into a single "less/more" virtual 
control so that all processing parameters work in tandem with each other. 
This works well for the person first opening the box and having a single 
control to get you 90% of the way there.  Then, optimize the individual 
controls to best match various operating conditions.   In the case of the 
K3, that's something like 8 menu controls dedicated to AGC, including the AF 
limiter function.  Not everyone who purchases a transceiver is adept at AGC 
management.

Paul, W9AC