For those wondering, here's a link to a recording I made of the sound back when I was having a problem: http://liltechdude.com/files/Recordings/kpa3squealrev2.mp3
I ran it through a spectral analyzer and produced this: squeal.png (image/png) 202K<https://mail.google.com/mail/?ui=2&ik=c5b17c1439&view=att&th=134f2e88d2107ef7&attid=0.1&disp=safe&realattid=f_gxkx14rr0&zw> 73 DE AB3LS On Wed, Jan 18, 2012 at 3:06 PM, Joe Harris <joseph.a.har...@gmail.com>wrote: > Thanks for the update, Geoff. I will contact Elecraft support to inquire > about a possible PA replacement. > > 73 > > Joe- N1QD > > > On Wed, Jan 18, 2012 at 2:39 PM, Geoff Wolf AB3LS <liltechdud...@gmail.com > > wrote: > >> 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 >> > > > > -- > Joe Harris, N1QD >
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