[time-nuts] FE-5680A Results so far
smither at c-c-i.com
Wed Dec 28 18:45:20 UTC 2011
Chris Albertson wrote:
> Just got my fe5680 yesterday. Seems to work but the fe5680 is the most
> accurate reference I have. So how to test it? I plan to buy a
> Thunderbolt but until then, anyone have any creative ideas?
> Going to have to get a Thunderbolt. I have an Oncore UT+ the provides a
> good pulse per second but that will not help
You can take the FE-5680 10MHz and divide it down to a derived 1 PPS. Use the
time interval measurement on your HP5328A to measure the TI between the Oncore 1
PPS (start) and the derived 1 PPS (stop).
You might want to set a finite TI (for example, 100 usec) by adjusting the phase
of the derived 1 PPS so the measurement doesn't get confused.
I have done this using an HP5316B with good results.
The jitter on the GPS 1 PPS might limit your short term resolution, but over a
day or so you should be able to measure the drift of the FE-5680A.
I have used a Ref Tek 111A GPS clock for the 1 PPS. That unit has a lot
(several usec) of jitter. I recently started using a 111C that has much lower
jitter (a few 10's of nsec). I believe your OnCore unit will be similar.
Here are some results from my tracking my FE-5680A:
Hope this helps.
Bob Smither, PhD Circuit Concepts, Inc.
"Patriotism is supporting your country all the time, and your
government when it deserves it."
- Mark Twain
Smither at C-C-I.Com http://www.C-C-I.Com 281-331-2744
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 140 bytes
Desc: not available
More information about the time-nuts