G'day, Did you have a light shining on the PA transistors? J3+ on my KPA100 had -0.18V. Apparently something to do with illumination of the PA's. Well noted by others.
Regards, Mike VP8NO ----- Original Message ----- From: "Gerhard Schwanz" <[EMAIL PROTECTED]> To: <elecraft@mailman.qth.net> Sent: Friday, February 04, 2005 10:42 AM Subject: [Elecraft] KPA100 Problem still exists, but some new measurements Hi there, I'm still on page 43 in the process and I have now narrowed the problem area. You remember, I measured a negative voltage of 0.15V on J3+. Now: I removed Z1 and found the voltage measured at the collectors of Qs 1 and 2 to be -0.4V (J3+ is ok now). I don't know where it could come from. Shorting the collectors to ground via 1k resistor it takes 3 seconds to eliminate the voltage. I measure 0V. Removing the resistor it takes abt. 20 seconds for the voltage to go to -0.4V again. T2-4,5 are ok. The base of the transistors are ok, 0V. The emitters also, 0V. The body of T2 also has -0.4V. Any idea and testing procedures appreciated! Kind regards Gerhard Schwanz DH3FAW mailto:[EMAIL PROTECTED] http://www.gs-personal.de _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
