I had a similar issue with my K3, it only happened on 15M. It got even worse with my KPA500 in operate mode. I removed everything but a dummy load and then started adding things back-RX antenna, KPA500, P3, etc... In my case, it turned out to be the mic cable pigtail. I put about a pound of ferrite on it and the erratic power output has gone away.
As a side note, I even sent it to Elecraft to see if they could find the source and as they correctly suggested, it turned out to be a local issue with my shack. The odd thing was that nothing about my shack had changed-operating position, antenna location, etc. It just started one day. Good luck, 73 K5RHD /randy 2014/07/08 11:09?NZ0T <[email protected]> ??????: > My K3 SN 1502 with MCU 4.83 is exhibiting a strange surge in transmit power > level. When the rig is keyed in CW with the power set all the way up power > output surges from a high of around 140 (!) watts down to 60 watts and back > in a rapid fashion. It is at it's worst on 30 meters shows at least a high > power spike on all bands except 160 and 80 before it settles down to around > 100 watts. If I turn the power down the cycling is much less severe but > there is still a leading spike of around 140 watts. I have tried reloading > the firmware with no luck. I have checked all my jumpers and connections > and they are fine and the rig does this even straight into a dummy load. My > power supply is an Astron RS-35M in great shape. > > I should mention that we suffered a lightning strike last Labor Day weekend > that took out my Ten Tec tuner, W2 wattmeter and a few other things but the > K3 was not affected at all and I hope this problem is not some delayed thing > from that strike! > > An ideas? The rig is almost six years old - maybe I need to open it up and > make sure screws are all tight? > > 73 Bill NZ0T ______________________________________________________________ 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 Message delivered to [email protected]
