[time-nuts] Thunderbolt behaviour with long time constants.
WarrenS
warrensjmail-one at yahoo.com
Wed Feb 9 17:19:36 UTC 2011
Looks to be mostly a plot of the 5370B's noise floor at low taus.
You may need something a couple of decades better if you want to measure the
Tbolt at that tau setting.
BTW, You should NOT set the TBolt's TC to >999 sec. I have found that the
control can become somewhat unpredictable, AKA S/W bug.
ws
*********************
----- Original Message -----
From: "Mark Spencer" <mspencer12345 at yahoo.ca>
To: <time-nuts at febo.com>
Sent: Tuesday, February 08, 2011 7:48 PM
Subject: [time-nuts] Thunderbolt behaviour with long time constants.
First apologies for the zipped attachement.
I thought some members of the mailing list might find the attached plot of
the
performance of my Thunderbolt to be interesting. After looking at the
performance of my Thunderbolt with a time constant of 225 seconds which
seems to
be about right for my Thunderbolt, I noticed that the Allan deviation
appeared
to be be reduced at high values of Tau (approx 2,000 seconds..)
I then changed the time constant of my Thunderbolt to 2,000 seconds and
compared
the two plots. I'm quite surprised at the result and the similarity between
the peformance at low values of tau with the two different time constants.
I took 4 readings per second with a 5370B, hence each unit of tau on the
graph
is approx .25 of a second.
I'll likley try other time constants in the future
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