[Elecraft] [K1] Internal Noise Bursts every 12 seconds or so

[Bob]

Great advice, Don.  I will try that soon.

The noise is raspy alnost static like. Not a ticking like you would expect
from digital noise.

I have mechanically probed every component lead and cant cause the noise
that way which I would expect from any intermittant connection. Nor does
rapping hard on the case cause it.  It simply repeats at its own pattern
rate: 1/2 sec burst, 1/2 sec pause, 3 sec burst, 8 sec pause,  endlessly
repeating.

73, Bob, WB4SON


On Tuesday, December 29, 2015, Don Wilhelm <w3fpr at embarqmail.com> wrote:

> Bob,
>
> Can you describe "noise burst" - is it more of a "tick", or if it is
> longer, what is the approximate duration.
> You will likely have to short the signal path at several points to isolate
> it.  One such point is the input to the product detector - solder a jumper
> between pins 1 and 2 of T2.  If it disappears, you will have to look
> further toward the antenna - jumper from the base of Q3 to ground (or
> between pins 3 and 4 of RP6).
> OTOH, if it is still present with the jumper across T2, the next jumper to
> install is between pins 2 and 3 of U3 (which should do the same as when the
> K1 is muted).
>
> 73,
> Don W3FPR
>
> On 12/29/2015 12:35 PM, Bob wrote:
>
>> Thanks for the ideas, Mike!
>>
>> Well I can rule out the Filter Board, as the noise is still there when the
>> Filter Board is removed.
>>
>> I hoped I could remove the CPU to see if there was an issue there, but
>> with
>> the CPU gone, the audio is eliminated (probably need to pull something
>> high
>> or low to get the audio back).
>>
>>
>>
>