[Elecraft] More information - Need help with fluctuating power output on K2

[Dean Fewkes]

With further testing I have found that the power output fluctuates mostly on 
the 80 thru 20 meter bands and 80 is the worst. It seems to jump back and 
forth rather than slowly drifting. It seems like the power control knob does 
not have very consistent control over the actual output.

I did some signal tracing and found that the same fluctuation is evident in 
the signal right after the "Xmit Mixer Output". This signal jumps from 27 to 
36 mV as the out put power jumps back and forth. While doing this test with 
the output power set for 5W, the real output power jumps from 3.5 to 6.5 
almost each time that I press the tune button to send. Since this is a 
pretty early stage, I don't think that the ALC control circuit is causing 
it. Doesn't the ALC adjust power after this stage? The VCO output just 
before the Xmit Mixer tested normal and stable on transmit and receive. What 
else could be causing the fluctuating signal at the Xmit Mixer Output?

I have still been using the radio and just running it on full power where is 
seems more stable. I have found that if the power drops while on full power, 
I can turn the power knob down and back up 2 or 3 times to make the power 
come back up. I know that the POT is working good because the power that 
reads out that it is calling for (when not transmitting) is very linear and 
stable.

Thanks again for any and all help!