I had some questions about this issue mailed to me. Here's my update.
Elecraft sent me a replacement KPA100 and KPA I/O board, of which I replaced myself. The new amplifier and I/O board fixed the problem. No more 12KHz resonation coming from the internals of the radio in test, low, and high power modes. The closest thing I can compare the sound to is the electrical resonation of a cathode ray tube in a TV, however, it's not as clean. Possibly a cold solder joint or bad connection between the amplifier and I/O board? I don't know. 73 DE AB3LS On Fri, Jul 29, 2011 at 4:29 PM, Bill W4ZV <btipp...@alum.mit.edu> wrote: > > AB3LS wrote: > > > > No go. > > > > Hooked the radio up to a gel cel battery and we're still getting the > 12Khz > > junk coming from something and the clicking between TX and RX. > > > > I made a longer recording of the 'junk' and posted it. Cycled between TX > > and > > RX a few times using the manual TX button on the front. Then finished off > > with a few dits and dahs. All while in TX Test mode. > > > > > http://alien.liltechdude.com/files/index.php?dir=Recordings/&file=kpa3squealrev2.mp3 > > > > Anyone from Elecraft have anything on this? > > > > FYI I noticed the same on my #4717 kit (delivered last September). I > normally use headphones so I never noticed it before. I believe ~12 kHz > was > getting into the DSP chain before the LPF mod to the DSP board was done so > perhaps that's a clue. BTW I have no switching PS anywhere and this is > definitely coming from the K3 itself. > > This would be VERY annoying to someone with good hearing in a quiet shack. > I can minimize it by slight head movement (standing waves) but that's not a > good solution. > > 73, Bill > > > -- > View this message in context: > http://elecraft.365791.n2.nabble.com/K3-KPA100-Squeal-tp6518460p6634869.html > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > 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 > ______________________________________________________________ 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
