Re: Q7 failure in K2

Posted by N9AUP on Feb 18, 2012; 10:39pm
URL: http://elecraft.85.s1.nabble.com/Q7-failure-in-K2-tp7297576p7297744.html

Thanks Don,

I've now pulled the remains of Q7 and also removed Q8.  I checked the bias and it is at .64 volts and present at both base pads.  This is a K2/10, so does that rule out the static antenna charge theory?  I have a sort of crude transistor check which consists of connecting ohm meter - to emitter and + to collector (NPN) then touching my finger across base and collector to see if resistance decreases.  If that means anything in this case, then Q8 wasn't totally destroyed.  Of course, I'll buy the K2PAKIT and install the matched pair.

I note that the receiver mode seems to be working just fine.  I pulled the controller board and turned power on and off to do a relay reset per the manual.  40 through 10 meters are open at the moment, the relays are clicking and I have reception across the board so the relays/filters must be ok.

Can you suggest anything else to check?

73,
George