[time-nuts] Comparing the frequency of two gpsdo's.

[EWKehren at aol.com]

I agree with Magnus Dual Mixer is the best way to go. That is why over a  
year ago I set out to develop a system that with counter can be realized for  
$200. I did reach that goal and Corby tested the first pass and the second 
pass  with 1 E-13 results. He used his SRS counter. Richard who wrote the 
code for the  five PIC's has tested the counter. What is missing some one 
testing the two  combined. I have a total of seven systems out there some on the 
condition that  they get on it with in two weeks. Sad to say it has not 
happened. I just send  out an other kit this week, maybe we will have more luck 
this time. Once a total  test has been done the third set of boards will be 
ordered and once tested made  available for any one. It measures frequency 
difference and Allan Variance with  a resolution 1E-15 the five channel 
counter runs off USB power and all is needed  is along with the reference is a 
one or ten Hz offset OCXO. 
I will not mention any names but I would like to remind you what  you 
promised the rest would appreciate the availability of a unit that everybody  can 
build and will be affordable.
Attached is the picture of the second pass with HP 10514 Mixer  courtesy of 
Corby. There are only two SMD  components!
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 116004 bytes
Desc: not available
URL: <http://www.febo.com/pipermail/time-nuts/attachments/20101113/f434e17a/attachment-0001.jpeg>