Dear everyone, This morning while I was running a CW net, using a VibroPlex Lightning bug, my KPA 500 seemingly went on the Fritz. I was running it at 300 Watts, on 7.123 MHz, paired with my K3 using the smart cables, and it was working perfectly until about 10 minutes into the net. Whereupon it stopped putting out power. The antenna to which it was connected via the KAT500 tuner, was a 160m OCFD. I subsequently checked the antenna with my Rig Expert analyzer to confirm that the SWR on the antenna at that frequency is 1.5.
When the KPA 500 stopped putting out power, the following were what I noted: When I went key down, I saw the little asterisk on the LCD screen of the KPA 500 appear corresponding to my key, but the green/yellow/red LED bars over to the right stayed dark. Readings on the LED screen when I pushed the appropriate buttons (with key down): PWR = 0; Temp = 23C; current = .9; HV = 68.2; keying asterisk appeared when I went key down. I checked the tightness of the smart cable connections on back of tuner, amp and K3, powered everything down and then back up, and the problem persisted. When the KPA 500 stopped putting out power, I put it in STBY as well as the KAT 500 in bypass, and continued on with the net, and I was getting out as confirmed by my 599 signal on an SDR in KY which I monitor during the net. Given that the little keying asterisk shows up when I go key down, but the colored LED bar does not light nor do I hear a signal on the KY SDR when the KPA 500 is in Operate mode, it seems like the KPA 500 knows it's receiving a key down signal from the K3, but for some reason it just isn't putting out any power. This amp is new to me, but I am unnerved somewhat because it stopped working in the middle of the net after working perfectly for about 10 minutes. Apologies if I am missing something totally obvious, but does anyone have clues as to what may be the issue, or what I might do to resolve the problem? Thank you. Jim Ewing N4TMM ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com