[Elecraft] ticking AGC on K2/100

[Dale Boresz]

Andy,

I had this exact problem a while ago before I moved my KPA100 into an 
external EC2 case along with the KPA100, and I was finding it to be very 
irritating as well. I stumbled upon the solution in the process of 
trying to determine the cause - and although this solved the problem, I 
don't really know why. Anyway, I discovered that (and now it's my turn 
to say 'this is going to sound stupid') if the speaker wire lies 
anywhere near the KSB2 board, this pulsing of the background noise 
occurs. I removed all slack from the speaker wire by bundling up any 
slack and wrapping a nylon tie-wrap around it so that it would stay up 
near the control board and away from the KDSP2, and the problem went 
away. Just to confirm that I had found the solution, I unbundled it 
again, and allowed it to route over the area of the KDSP2, and the 
pulsing returned.

Regarding why you seem to only see the problem in the morning on a 
relatively 'empty' band, my guess is that there's simply nothing else to 
pump the AGC levels around, so you notice it. As band activity 
increases, the AGC is being activated by signals which are much stronger 
than the signal causing the pumping action, so it's less noticeable.

I hope this helps.

-Dale / wa8sra

Andy Bullington wrote:

>I know this is going to be something stupid when I finally get to the bottom of it, but right now it's driving me nuts.  Every once in a while
>(usually in the early morning) I notice a pulsing of the background noise....
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