I am not positive, but I cannot see why the absolute value of the clock is of any matter.
Since the computer doesn't know what the frequency of the radio is, the only thing that I would expect to matter is the moment to moment accuracy of the clock (i.e., drift and jitter). The thing that I find is most critical for me are all the level settings. On my initial setup, I had the same problem you are describing. When I looked at the raw, digitized soundcard output (using a WAV editor) the distortion was amazing even though it didn't sound bad in the speakers. Getting the right mix of radio volume, interface gain, and soundcard setting was a fairly long experiment. Once I used the raw waveforms to adjust the levels for maximum signal with minimum noise and distortion, I have had excellent results. My soundcard is a generic $20 one. I am using an Alinco DX70T into a swapmeet MFJ tuner hooked to a wire antenna (Windom) strung between tree branches in the yard. So far I have been able to QSO with Namibia, Japan, Australia, Russia, and Eastern Europe all on 80-90 watts. I have also QSO'ed both coasts (I'm near Houston) with QRP levels. As you can tell, I have become addicted <GRIN>. So my recommendation: Pay detailed attention to the levels! They are generally set lower than what I would have normally expected. If you still have the problem, start looking at the soundcard first (expensive is not always better). Just my experience, hope it is useful. Good Luck, Ron, AG5RS
