Hello Jerry,
thank you for suggestion regarding the QSK? click noise.??? Got my QCX? running on 30m band for some days?? and had also to find a kind of sweet spot for the side-tone? level? fitting my? my combination of QCX, OP, and uses earphone.??
I ended up with '75'? ..that works for me? using? a simple headset? from Samsung supplied with my mobile phone. ?? ?? So for me it works without an extra AMP? for level control, the click is still there, but? does not interfere with my CW monitor feeling nor? is to noisy to? kill the great QSK feeling.
I tried to figure out,?? what causes the click ..or better the complete noise that happens :) ...??
I'v got at least three? different source:
*?? a low frequency ' whupping"? sound? from QSK it self...?? this is? a full show stopper for using by? HiFi Headset?? that is able to bring in this bass tones... maybe caused by the DC shift of the OP Amp?
*? a click?? caused by the QSK .. but happens only after the first dot...? second dot ends with a click.. first not...??? ( around Speed 25)
*? Hum? ...? simply? caused by? RF feedback into the audio part... not loud, but part of the game.
Using the relative? high level? side-tone? masked this sounds, because the side-tone? a lot of harmonics .. so the Audio CW bandpass does not really work perfect for side-tone on higher levels.. ( 1400 tone only -20db for me at side-tone level 75...?? from the Audio Filter curve you should expect at least - 45.. )???? so side-tone is no pure sinus.. and this works to masked the qsk noise :) ..?
I found the nice -45 db harmonic down at a level if sidetone 50 ...??? you really hear the difference...? but the QSK noise is terrible ;) ..and semi BK is? really great.. ? ?? ( if you? bring down the RF noise but using a well desingend antenna ;) .. not the? kind of random wire,? I have to use...) ?
The best of all testing...? I learned? that it? is really? tricky to? see the 'click' part? of the audio on your scope to learn more about it's timing? in order to add a extra signal in the right moment for the click banking FET .. ??
But this would be a kind of real nerd stuff...?? the QSK click? does not really stop me from? having fun with this great? QCX radio...?? and because the RX is that great,? it's really worth to get? 100% out of it instead of 95 %? even his brings only a little bit more fun? in daily work. ;)
73 de Olaf / DL5YBZ
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