[time-nuts] question Alan deviation measured with Timelab and counters
steph.rey at wanadoo.fr
Fri Jan 9 06:53:36 EST 2015
I'm trying to measure Alan Deviations using Timelab and some frequency
The device under test is a GPSDO using a TCXO as référence
I've an HP58503B GPSDO which feeds my counters. I've tried an HP5342A,
0-18 GHz, 1 Hz resolution and a Philipps PM6654C, 0.01Hz resolution.
In Timelab, the plot with the HP5342A is around 10e-7 which correspond
to 1Hz and with the PM6654C, the plot is around 10e-10.
I would suspect that this is still the counter which limits the actual
response of my device under test.
My question are :
- how to measure Alan Deviations with levels below 10e-12/10e-13 ? What
can be the application of measurement Alan deviation > 10e-10 ? I guess
most of the low frequency
- The HP53503 GPS is given to be 10e-11 / 10e-12. I guess this will
limit anyway the measurement floor. I've a Rb source, but it's stability
is within the same range. What kind of reference would be more suitable
for such measurements ?
- With the PM6654C on 15h measurement, I can see some frequency jumps
of 800 Hz which are not relevants with the GPSDO undertest. I suspect
error in data transmission. This makes the overall measurement totally
wrong (10e-5). The counter is in talk only mode. I'd like to get rid of
these points maybe 40-50 points out of 10000. Is there a way to do that
from Timelab or the only option is to export the file and process
manually the data ?
Thanks & cheers
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