At 18:26 2/12/2003 +0000, G3KEV wrote :
Hi Rick
If not too difficult maybe 20 khz top freq would be useful for a bit of
tolerance for some IF outputs.
73 de Mal/G3KEV
Hi Mal,
Using the soundcard the theoretical limit is 22kHz (22.05kHz to be exact)
assuming as 44.1kHz sample rate.
Using the PC speaker one can go much higher, but at higher frequencies the
steps become rather large as the PC speaker tone is derived from a
1.193182MHz xtal source, divided by 2 - 65536. So the theoretical limits
are 18.2Hz to almost 600kHz.
20kHz would be derived as 1193.182kHz / 60 = 19.886Hz (so a 114Hz error).
The next lower frequency would be 19.560kHz, the next higher 20.223kHz.
73, Rik
PS : Although the upper limit is almost 600kHz forget about using the PC
speaker as a 137kHz signal source : 1193.182 / 9 = 132.576kHz and 1193.182
/ 8 = 149.148kHz.
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