I have been trying to work out why I have such bad copy of WOLF and 
WSPR (on HF as well as 500kHz) and others report it as 'plug and go' 
and came across a page at http://wsprnet.org/drupal/node/336 which 
explains the problem exactly. It seems that both WOLF and WSPR are 
designed for current sound cards which have 48,000 and 96,000 clock 
rates. Mine is obviously from the old stable so has 44,100 etc rates.

For information it is the sound card interface built into the 
motherboard, an ASR Rock K7S41GX dating from 2003 with generic AC'97 
sound. Zilch more given about its spec in the manual.

I did a test using a 40m broadcast carrier on 7355kHz, with the K2 
tuned to get a 1.5kHz tone.

Argo reports it correctly at 1502Hz, pretty spot on
Wolf (default 8000Hz sampling) reports 1553Hz
WSPR (2000Hz sampling) reports 1534Hz

Obviously the interpolation works differently for the different 
sampling rates of WOLF and WSPR but the effect is obvious.

Being an older card there is no way it will support the 48,000 etc 
sampling rates natively, and there is certainly no switch. In Wolf I 
can play around with the calibration, but there seems no way to do this 
in WSPR.

At least I now know why I, and presumably others, have problems.

73 Dave G3YMC

http://www.davesergeant.com