[Elecraft] K3 AGC Mush

[Eric Swartz WA6HHQ - Elecraft]

We actually have a 'pile-up' generator we designed that sends multiple 
cw signals. So far it has not reproduced the issue here.

What is the signal spacing you are hearing this with? All -exactly- on 
the same freq? Or spread out?

73, Eric

_..._


On 12/4/2011 12:20 PM, Jan Erik Holm wrote:
> This is exactly what I have noticed too. Not even 10 signals
> are needed either.
> /SM2EKM
> -------------------------------------------
> On 2011-12-04 20:53, Merv Schweigert wrote:
>>> Also, in the heat of the contest or DX pile up most reporters do not
>>> recall how they had their AGC parameters set (threshold, slope, AGC
>>> decay soft/hard, fast or slow, and fast/slow settings etc. If you can
>>> let us know your complete set up for AGC parameters, if you are using
>>> headphones or speakers,  the signal strengths, CW or SSB, RX b/w, what
>>> different settings you tried etc., that will be extremely helpful.
>>>
>> AGC DCY  =  NOR
>> AGG HLD  =  20
>> AGC PLS  =  NOR
>> AGC SLP  = 000
>> AGC THR =  008
>> AGC F      = 200
>> AGC S     = 020
>>
>> Headphones and speaker, no difference
>> signals S3-S4 range
>> CW
>> all bandwidths,  use mostly 400hz and narrower.
>> Tried AGC DCY = SOFT  (have PF1 programmed to switch that in and out fast)
>> ALL settings of SLP and THR
>> Turning off the AGC  improves the "mush".
>> Loud signals are no problem at all,  the K3 handles loud signals better than
>> any radio..  its when multiple signals of about S-4 are on this occurs,
>> more
>> than two or three, a pile up of same strength signals.
>> I can understand it may difficult to reproduce unless you have a way to
>> have
>> 10 signals of the same strength, close to the same freq, and keying,  just a
>> carrier will not reproduce the effect,  has to be keyed signals you are
>> trying
>> to copy.  They turn into a single level buzz of sorts.
>>
>> One note - If signals are below S9+20 and turning AGC off does not help,
>>> its probably not a DSP AGC or H/W AGC issue.
>>>
>>> Also, make sure to use the AGC Limiter menu setting to hard limit audio
>>> levels if you use AGC OFF.
>>>
>> Never use NR or NB  and have the AGC limiter set for no AGC times.
>>
>> In my rough gestimation it seems that signals in the S3-S4 range need to
>> not trigger
>> the AGC as they do,  if one could set the THR to higher level? perhaps
>> it would stop the
>> problem.
>> Is it possible to increase the range of SLP and THR to move the point
>> where S-3 or S-4
>> signals trigger the AGC?
>> Thanks much Eric.    73 Merv K9FD/KH6
>>