[Elecraft] KPA100 oscillation during IARU Reg 1 Field Day

[Jukka Tarvainen]

Hello!

Sunday afternoon my KPA100 started oscillating, I believe. It happened just
when heavy rainshower hit our site. I was using a Spiderbeam on 20 meters
and running small CW pileup with 100 watts. Rig was performing well for 18
hours on various bands and it was running quite hot. I put fan running high
continuously in the beginning of contest.

When this happened I disconnected power supply. K2 seem to work normally
when KPA100 is not active. When KPA comes on it shows "Hi refl" immediately
when transmitting and draws 20-30 amps from 30 amp power supply. Power
supply starts to limit and cuts power.

There was some smoke smell coming from K2. Can't see any blown away parts.
Couple of 2 and 3 watts resistors have been warm, they are bit brownish. Any
ideas what and where to start looking for? I built my K2 and options, but
I'm technically challenged :)

Jukka Tarvainen, OH4MFA
K2/100 #4293
oh4mfa at sral.fi
http://personal.inet.fi/koti/oh4mfa