I put my new KPA500 (s/n 1057) together earlier this week and have been loving it, although it has seen only light use so far.
However, that changed this afternoon. I used it briefly on 40m LSB a few hours ago and all was fine. About 35w of drive for 550w out. I just retuned the antenna to the low end of the band, yielding a 1.0:1 SWR at the K3 in the standby mode of the KPA500. When I switched the amp to operate and keyed the transmitter (tune control), the amp power LEDs jumped up to about 500w and then went to 0. Subsequent keying show a very high SWR at the K3 (65 to 99:1) and the K3 puts out no power as does the KPA500. I tried a dummy load with the same result. If the amp is in standby mode the K3 acts right and the power and SWR LEDs on the KPA500 act right (100w out at a low SWR). Putting the amp into operate mode acts like the input SWR is very high. I tried tightening up the cables at both ends (BTW, I am using the control cable between the rig and amp for maximum integration, and the K3 knows to reduce the power out when the amp is in operate). I hope I am doing something wrong, and the fix is simple. Any suggestions of where to begin? Thank you. 73, Phil, NS7P ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
