[Elecraft] PA set up issues

[GD0TEP]

Hi to the group,

 

I've just installed my KPA3 100w upgrade into my factory built K3.

 

I've followed the calibration procedure starting out with 5w per band, and
then moved to 50w per band, as per instructions.

 

I must be missing something, or perhaps not understand what I'm reading as
once I've completed the calibration, some of the HF bands are fine with 100w
out, other bands seem to upset the radio as follows: When using the radio
into a 200w 50 ohm load, and measuring power with a bird 43, I can see how
the power increases as I raise the power output, yet on certain bands there
seems to be a point where at around 85w to 90w the power out appears to fold
back and the radio switches itself off. 

 

There doesn't seem to be any link to what band is causing the problem, as I
have the problem on 160m, 30m 21m 12m, 10m and 6m.

 

So, what am I missing, or perhaps I should ask 'what have I done wrong or
forgotten to do'??

 

73,

Andy

http://gd0tep.com