I have to admit, I just have not experienced any of these "issues" with either of my K3s. Yes, I am mostly a CW guy and yes, I use headphones.
So...lacking any "real" test equipment (I assume that if the test equipment between my ears can't discern it, then who cares what a meter or scope shows me). Crude, I know, but this worked well for me one summer, in 1974 when I worked for Signal/One. They had all the test gear and engineers (this was when they moved to NJ), but nobody there could figure out/understand what was "wrong" with the radios returned for repair. All I needed was a couple minute with the radios (on the air) to quickly "discover" what was wrong and THEN the engineers could apply a fix/repair. http://picasaweb.google.com/dougzzz/KR2Q1966ToPresent#5419152602223700290 Anyhow, someone recently made a great post (IMHO)...sorry I can't remember who it was, listing the three "problems." So I decided to "test" the K3s using what I have here (my ears, acoustic nerves, and brain). First, I have my cw pitch set to 400hz. Using the CWT feature, I "zeroed" in a cw signal. Heard it FINE via the inboard speaker and equally as fine via my communication headphones (the headphones sound great on CW, but I can tell that they are getting "restrictive" on SSB on the top end). Then, using my RIT, I dialed in 200hz offset (making the received signal "lower" in pitch). Using my headphones, the signal seemed fine...perfectly readable, good tone, easy to copy. Then I pulled the headphone plug to listen via the internal speaker: NOTHING. Just some "thunks" - I could not copy any signal at all and I certainly could not read any CW. So I plugged the headphone back in and BINGO....perfect, smooth, easy copy with a 200hz note. A real difference. I am thrilled that those who have implemented the new DSP board with LPF can now "hear better," but I have to wonder how much of this has to do with trying to do too much with an internal speaker. I don't know and I am not conjecturing....I'm just wondering. At least now, I do know why I have not experienced most (any?) of these audio issues. If I find a pair of "quality" HI-FI stereo phones around the house somewhere, maybe I'll plug those in and see if I can duplicate the "noisy receiver" problem, suspecting that is due to "hiss" as others have suggested. Right now, using communication headphones, I can not. One last thing that I do not understand...and I am hoping someone can answer me. Why would riding the RF gain or adding Attenuation in any way impact "noise" (assuming it is not due to intermod)? Today I tried that again and again. Adding in attenuation simply reduced the audio output (again, according to my EAR). Yes, the "noise" went down, but did the signal. When I upped the AF gain to compensate, well, everything sounded "the same" relatively speaking (signal and noise) as with no attenuation. If the "noise" is not due to intermod (what Elecraft calls "desense") then what can cutting back on the total signal due in terms of making "less noise?" I am not a "technical" guy. I just have lots of ham radio experience. My UG degree is in Biology (BS). I did my first graduate work at U Penn School of Veterinary Medicine (VMD) and my 2nd grad degree earlier this decade in Healthcare Administration (MHA). Like I said, I'm no "techie." :-) Wishing everyone a Happy New Year for 2010. de Doug KR2Q ______________________________________________________________ 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
