[time-nuts] Updated Divider Jitter Results

Magnus Danielson magnus at rubidium.dyndns.org
Sat Apr 4 12:27:49 UTC 2009


Poul-Henning Kamp skrev:
> In message <49D740D1.1030600 at febo.com>, John Ackermann N8UR writes:
>> Sure.  I didn't write down the numbers because it was an interim step, 
>> but I earlier did that and IIRC the std dev was around 20-25 ps.
>>
>> Would error in the cal circuit tend to falsely increase, or decrease, 
>> the result?  Or both?
> 
> In my experience it generally skews your result downwards, but I have
> seen it move upwards also, it all depends on the phase.

I have seen how it skews both ways. With a very sensitive hand a minimum 
can be found which can be fairly low, such as 13 ps but then I had tuned 
the 200 MHz section carefully. Getting such low results on a general 
signal is not possible. Also, the ref out of the HP5370 has a wideband 5 
MHz signal with overtones noise which can be removed if modified. 
Modifications requires one little short-out.

Cheers,
Magnus




More information about the Time-nuts_lists.febo.com mailing list