For the sake of the Archives, here's the epilogue. I replaced D1 and D2, with no change in behavior. Tracing showed that there was close to 0V at the outputs of U5 during transmit. With power off, the resistances at the inputs of U5 were about 10 ohms! The op amps must have been zapped as well. I replaced U5 and now all is well. (I also repeated the Power Calibration alignment step).
Thanks for the help. 73 Jonathan > Jonathan, > > If it was working before, it may be that the wattmeter bridge diodes in > the KAT100 were zapped with a lightning surge. > > I suggest the first step is to obtain 2 1N5711 diodes and replace D1 and > D2. While you are doing that, check the soldering/tinning on the leads > of T1. If that does not restore normal operation, other tests may be > done. > > BUT - if it has NOT worked properly before, you may have other problems. > In that case, check T1 very carefully to be certain the correct leads > are in the proper holes and the leads are well tinned and soldered. > > In the future, for your personal safety and the health of your > equipment, disconnect antennas when not in use. > > 73, > Don W3FPR > > Jonathan Taylor, K1RFD wrote: >> After working OK for several years, my KAT100 no longer indicates SWR, >> nor >> does it tune properly. >> > > > _______________________________________________ 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
