[Elecraft] K2 PA100. I hate it when I am stupid.

[Rich McCabe]

Well finished the 100 watt PA tonight and did not spend as much time
checking components as I should have :(

All resistance checks where good and everything checked out (fan, swr cal,
ect) until I got to the point where I powered the K2 radio from the high
current supply. I detected a "crackle" on power and shut it down to check.
All looked OK so I tried it again. Seemed OK and everything looked good with
current draw but the bias would not adjust at all. Just stayed around 600.

So I started doing resistance checks and across the power plug  it was
several hundred ohms and not > 10K it should have been. This checked OK
originally without power. So I start lifting components to narrow it down
and I get back to U7 and if I had looked in the first place, I would have
noticed I put it in backwards <sigh>

So upon removal the resistance across the power plug is back to normal. I am
sure U7 it toast since the resistance was OK before power and not after. Can
someone tell me if there is anything else I should order when I do? Maybe
Q5?

That is what you get when you dont follow directions !

73,
Rich
kdozv