[Elecraft] KDSP2 and W3FPR fixed audio out, frequency rolloff

[Don Wilhelm]

Sjoerd,

If your fixed audio output is connected to the VOL1 and VOL2 signal lines
(as in my suggested connection points), then the KDSP2 is upstream of the
fixed audio output, and there should be no change in the loading of the
product detector due to the fixed audio output.  OTOH, if your fixed audio
output uses the PD1 and PD2 signals, then yes, you may have a different load
presented to the product detector - furthermore the KDSP2 will not provide
filtering for the fixed audio output when connected to PD1 and PD2.

One other comment - the KDSP2 (and KAF2) adds a low pass filter at all
times.  Could it possibly be the effects of that low pass filter that you
are seeing?  The cutoff is supposed to be higher, but you could have
something awry with the KDSP2 - set the KDSP2 to BYPASS to see if the
condition changes.

73,
Don W3FPR

> -----Original Message-----

>
> I am using a W3FPR-like fixed audio out for my K2 for abt. 3 months now,
> worked very well until now.
>
> After installing my new KDSP2 the audio to the PC seems affected.
> In the original setup the high frequency rolloff was abt. 2 dB
> from 400Hz to
> 2.6 KHz.
> Now it is abt 6 dB over the same range.
>
> Any suggestions how to compensate for this??
> It looks like the output of the product detector is loaded different with
> the KDSP2.
>
> Any help would be appreciated!
>
> Tnx in advance,
>
> Sjoerd
> PE2SVN
>
> K2 #5095
>
>