17 Oct
2008
17 Oct
'08
9:02 a.m.
Curt Nixon wrote:
I expect that the faster the soundcard samples, the better?
It's counterintuitive, but through the magic of sampling theory, once you sample at twice the maximum frequency of the signal you are interested in you know _everything_ about it! As a practical matter, most ham gear audio rolls off sharply above 3 kHz (and SSTV is lower than that) , so sampling at a measly 8 or 11.025kHz rate is plenty.
Howard Long wrote:
Do you know of detailed texts that are public domain? If so let's have 'em!
And it's not public domain, but it is available as free software: check out QSSTV for source code.
If you are interested in sampling theory, check out http://www.dspguide.com/ch3/2.htm
-Joe KM1P