Hi Eric, I remember few years ago we had a similar problem with digital AGC at work with a chipset and in order to reproduce the field problem I had to add a noise generator (via a channel emulator) on a top of multi-carrier generator to catch the bug, noise floor and noise characteristic was the bug trigger. Most likely sound like a software bug and this kind of bugs are hard to trace. Hopefully in a week or two I'll get my K3 and I'll try to play with it at work in my lab. 73
VE3GNO Daniel From: Eric Swartz WA6HHQ - Elecraft <e...@elecraft.com> To: Jan Erik Holm <sm2...@bdtv.se> Cc: elecraft@mailman.qth.net Sent: Sunday, December 4, 2011 3:31:29 PM Subject: Re: [Elecraft] K3 AGC Mush 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 >> ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
