[Elecraft] K1 and FP U2

[Don Wilhelm]

David,

The signal from U2 pin 1 is indeed analog.  In normal transmit it should 
contain a square wave at the frequency of the sidetone pitch.  During 
receive, the voltage level should change as you switch from filter to 
filter.
If you have power control in the K1, then the other output from U2 is 
working, and that rules out the MCU.

73,
Don W3FPR

On 7/1/2013 8:07 PM, David L DuPuy wrote:
> Don...  I was unable to find any further loose parts (from speaker
> nut/washer) in the front panel area.  They appear to have lodged on the
> rear panel, but could certainly have bounced around a bit.
>
> As for weak signals, I was camping the the Yukon, so maybe why I was
> hearing weak signals!
>
> So it sounds like we are down to FP U2.  I don't look forward to trying to
> replace it ! but guess I'm going to be trying.  That's an analog signal out
> of pin 1?
>
> I now notice that switching filters has no affect on the bandwidth...
>   maybe that confirms that FP U2 is in need of replacement?  Can we rule out
> the MCU?  Appreciate your help.  David
>