[time-nuts] 10MHz Rubidium reference source for frequency counter
csteinmetz at yandex.com
Fri Oct 31 23:40:04 EDT 2014
>It seems to me that it's just a case of expecting too much from a counter.
Possibly, but a well-tuned 5370B can get to the low e-12's at 1-10
seconds. It has better one-shot resolution than the Pendulum, but
not by a factor of 10. So, I'd have thought the Pendulum would at
least get to the mid e-11's if the time base was up to it.
>To get the best performance from a counter, you need to set up the
>trigger thresholds well away from ground as Charles says. Also
>consider taking TI readings rather than frequency
>readings. Frequency readings are OK for initial setup and basic
>ADEV comparisons but they won't generally yield the best ADEV
>fidelity or the lowest possible measurement floor.
Yes, using TI mode is essential for getting down to the counter's
limits. Was Karen using frequency mode? I wasn't paying attention
to that end of things.
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