[time-nuts] GPSDO - Does it work?
Chris Howard
chris at elfpen.com
Mon Jul 15 16:00:47 UTC 2013
On 7/15/2013 10:09 AM, Bob Stewart wrote:
> In this case, I was using the 10MHz output from the GPSDO as the reference and measuring the 5MHz output from the GPSDO. So, even if the GPSDO is off in frequency, the relationship between the 10MHz reference and the 5MHz signal are mathematically fixed. It just seemed strange to me that under such a circumstance the final count would wander only in the minus direction. I expected either to see a solid 5.0000000, or to see it wandering between 4.9999999 and 5.0000001.
>
> Bob
If it is counting events, that means it never rounds
up. So half the time starting with a 4 and half the time
starting with a 5 means that you are in the window between
(5 + delta) and (5 - delta) for a very small delta.
If all you ever saw was 5.000... then your little window
is somewhere in between 5.000...0 and 5.000...1
Is that really where you want to be?
4.9999... is your friend.
Chris
w0ep
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