[Lowfer] Sound Card Drift - Empirical Observation

[Andy - KU4XR]

While using WSPR-15; I recently observed an ever so slight
shifting ( drifting ) of the DSP Filter passband as it 
showed up in the waterfall.. With no audio from the radio,
and just enough gain from the filter to produce noise; I 
could see a 1/2 to 1 cycle shift in frequency as the temp.
in my room would change.. As the air warmed; the PC warmed 
inside the case also, and the frequency would drift upward, 
and down, as it cooled.. I have super el-cheapie sound cards,
and for their intended use; they do what they're supposed to 
do..... Play Sound... But the thought did cross my aging mind,
that, those cards have a crystal on them.. If the crystals in
my radio can drift with temp. change; I figure that the crystal
on the sound card can drift just the same, and affect the 
sampling rate... which we interpret as " frequency " ...

Just my observation, and itchy typing fingers wanting to type.. hi - hi

73 all:

Andy - KU4XR