[Elecraft] [K2] Lost 80m recieve.

[Don Wilhelm]

Alan,

First of all, transmission at a fixed frequency of 3712 is indicative of 
a problem with the VCO/PLL.
Are the R30 (VCO voltage) values within range on all bands?  That is the 
starting point.

Next put the internal probe into TP1 and measure the frequency when the 
K2 is tuned to 3500, and also at 4000 kHz.  The measured frequency 
should be near 4913 kHz above the frequency shown on the K2 display.

If the frequency is not correct, the K2 will transmit on the wrong 
frequency.

Give us the results from the above tests and we can proceed from there.

73,
Don W3FPR

On 9/5/2011 8:40 PM, Alan Davenport wrote:
> Hello,
>   
> I have lost 80m receive on my K2 S/N:7012. I had this problem during the build but it "fixed itself" by the time I sorted out some other problems. 80m was working just fine for 6-7 months. The problem has returned.
>   
> Injecting a signal starting at the antenna, I get nothing on either side of K8, nothing if I inject at W1, and very weak signal if I inject at the output of relay K2. Strangely, it will TRANSMIT on 80m with normal power levels but it outputs a signal at approximately 3712 and that does not change when the VFO is changed. The VFO digits change as expected as the dial is rotated.
>   
> I re-soldered all connections for 80m from in the band pass and the low pass filters. I temporarily removed the ATU to remove that from the equation with no effect on the results.
>   
> It seems significant to me that it will transmit and that the transmit frequency is fixed at an incorrect value. Honestly though I am at a loss and need some advice as to how to proceed. Any help will be greatly appreciated.
>   
> 73 de Al, W2GZN
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