Hi Geoff, below... On Thu, Jun 30, 2011 at 9:24 AM, Geoff Wolf AB3LS <[email protected]> wrote: > And, for even more information, I analyzed the audio that I recorded and the > squeal is right around 12Khz. It peaks at -48dB (louder than the QSK relay > clicking) > > http://imgur.com/V8o5t - image of the analysis > > AB3LS
With your image I realize I had been making some assumptions. I need to fill in some details... Are you listening to the audio in earphones or are you hearing it in the free air. I had been assuming listening with your ears only in free air to miscellaneous sound in the neighborhood of the K3. *ASSUMING* open air, what did you use to record the sound levels? Would point out that the recordings don't get the sound to me, possibly because the program devices you are using won't pass 12 kHz. It would we difficult for me in any event as my hearing can barely hear anything at that frequency. This as opposed to MY college days, when I could hear 15 kHz made by the old analog TV set sweep generator. There are a lot of us in that highs reduced hearing state, so many will tell you they don't hear a 12 kHz squeal. And they don't, whether or not it is there. Likewise, any clicking that is made from a 12 kHz basis. In any event, I doubt it is being transmitted (have someone check up and down 12 kHz from you sending) because a spectral purity issue would have been beaten to death here (no shortage whatsoever of beaters-to-death on the reflector). There WERE some spectral purity issues early on that needed physical mods to boards and are standard in the mfr version for a long time now. The puzzler is hearing it when the KPA is set to "not installed" in the config menu. This leads me to wonder if you have that spur from your power supply. You ARE talking about a level that would pass spec. It could be that there is something in the KPA that is mechanically resonant to 12 kHz and will respond to it if it is on the power. You will need to put an audio scope on the power supply. In any event, you need to rule out having stuff on your DC lead from your power supply. 73, Guy. ______________________________________________________________ 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
