Is this behavior present on all bands or just 40 meters? You might try using the KPA500 without the control cable, as well.
73, Scott, N9AA On 9/21/12 8:01 PM, Phillip Shepard wrote: > 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:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
