[Lowfer] Ultra accurate soundcard calibration

[ToddRoberts2001 at aol.com]

In a message dated 3/3/2013 2:59:59 P.M. Eastern  Standard Time, 
jrusgrove at comcast.net writes:
Todd

Guess it's all a  matter of accuracy.

I've found it impossible to get Argo long term  accuracy any better than ± 
.01 Hz. It seems as 
through one runs into  'rounding errors' or something similar preventing it 
from remaining spot on  
... if it can even be made to be spot on in the first place. The best I  
could guarantee a frequency 
readout using WWV 500 or 600 Hz tones to cal  Argo would be ± .02 Hz.

While ± .02 Hz is more than accurate enough for  an Argo display 
considering it's internal ± .01 Hz 
limitation, the same is  not true of WOLF which can measure to .001 Hz. 
WOLF can not be cal'ed  
directly using the WWV 500 or 600 Hz tones because the WWV signal doesn't  
provide the level of 
stability required. If one takes the cal information  from Argo and 
manually modifies the WOLF 
sampling rate accordingly the best  one could hope for would be a similar 
accuracy as that of Argo ± 
.02 Hz. The  Ultra Accurate Soundcard Calibration setup can cal WOLF to 
better than .001 Hz.  Whether 
this level of accuracy is important is open to debate. All I've done  is 
show a way of doing so 
without highfalutin test equipment.

Jay  W1VD  WD2XNS  WE2XGR/2  


Thanks for all the info Jay.  
 
73 - Todd WD4NGG