[Kenwood] PSK31 and sound card sampling rate.

Thu, 4 Apr 2002 19:35:51 -0500

----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Cc: <[email protected]>
Sent: Thursday, April 04, 2002 6:26 PM
Subject: RE: [Kenwood] PSK31 and sound card sampling rate.
> No what I meant is that the WINPSK.DLL programs do not display the correct
characters.
> Where as the DigiPan does. DigiPan sets the sound card to sample at
11025hz.
> The WINPSK.DLL is supposed to set the sample rate at 8000hz. But I think
it's not.
> The sound card is stuck at 11025 sample rate.

Yes John, as I said, it seems you want to know how to manually set the
soundcard to 8000 SPS instead of 11025 to see if this corrects the problem
with the characters in WINPSK. Is this not the case? I must be having a
flashback (or perhaps a senior moment). :-)
What soundcard are you using, and what app are you using to adjust it's
input level?
> The reason I think this is so is that the
> xtal oscilator to the sound chip (ESS 1869) is 14.31953 vs 14.31818Mhz or
+90ppm
> error. This is not much of an error.

I agree, as I had previously suggested - a clock rate error of this
magnitude probably has no effect.
> But when I receive a PSK31 signal with WINPSKse
> I get errors of -5000ppm to -7000ppm which is huge!!!!

I'm not familiar with WINPSK. Does it display error rates expressed in PPM
or are you calculating this from something??
> Also 60% of the displayed text
> id garbled.

Heh, heh... funny that a typo popped up in that sentence. :-)
> I think, but again I'm not sure, the sound card is sampling at 11025hz and
not
> 8000hz. But how do I prove this?

Make a recording of the received signal in wav format, and look at the
properties of the resulting file?
In fact, you might use Windows' sound recorder to force the card to the
bitrate you want. Perhaps it will stay there afterward if WINPSK is not
explicitly configuring it.
For what it's worth (this thread has been rather convoluted) - Windows sound
recorder on *this* machine shows the exact list of available sample rates as
I indicated in a previous post as being useable by my soundcard. If you
don't now know what rates are available on your card, doing this will show
you that info as well. Again, this may be OS dependent.
de KA3ESF