Don: Thanks for the quick reply. Indeed the voltage at pin 5 of U6 is as expected (2.31 for 11.9 v in).
To be sure: the firmware chip is U6, on the control board?? I'll replace that and see what happens. If I may continue with my litany of problems since they may well arise from U6(ctrl brd): The receiver works well but problems show up on transmit. On initial test, it indicated excess current even at lowest power setting. After several trials, it would no longer switch to transmit. (The voltage at D6 anode rises to about 4 v then drops in spite of having 7.9 v at the emitter of Q1 (ctrl brd)). Pin 2 of U8 (ctrl brd) remains at 0 v though there is 0 v at the rf det on the rf brd. Right now I'm not ruling out a problem from Q5 through Q8 on the rf brd, which may have fried U6 (ctrl brd), so I'm still looking. Are these problems compatible with a faulty U6 or do I need to continue looking? joe carney KB3FBR If you find the voltage going into U6 pin 5 is the same as at U3 pin 7 and your voltage display still says 23.3, the only cause can be a bad input on U6 (in that case, you need to replace the firmware chip). 73, Don W3FPR _______________________________________________ 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
