[time-nuts] Calculating frequency differences using Lissajou figures

[J. L. Trantham]

And you watched it the whole time to see the 'reversal' of the rotation.  

Once going, it is not possible to tell 'which way' it is rotating.  In other
words, can you tell if it is rotating clockwise or counter clockwise?  

I would suggest making the GPSDO the 'trigger' for the scope and watch the
LPRO on one of the input channels of the scope.  If I recall correctly, if
it moves left, the LPRO is high and if it moves right, it is low in
frequency.  Please do not quote me on this as I have had a glass of wine.
After all, it's 5 o'clock somewhere.

Joe

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Hal Murray
Sent: Saturday, November 07, 2009 3:50 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Calculating frequency differences using Lissajou
figures


>>> So your frequency drift in this example is 1.7e-11 / month.

>> Not quite, you need to take the sign of the frequency difference into 
>> account.

> But the sign of the difference would be obvious from the rotation
> direction of the Lissajous.   

Only if you remembered to include the direction when you took the first 
measurement and if you connected the scope up the same way a month later.


-- 
These are my opinions, not necessarily my employer's.  I hate spam.




_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.