Hi
It's a pretty good bet that at 10 minutes the OCXO is still trying to stabilize
from a temperature step.
Do you know which oscillator your Tbolt has in it? There have been several
different ones used over the years. Some are better than others ...
Bob
On Dec 28, 2009, at 1:45 PM, Mark Sims wrote:
>
> The HP 10811A (generally regarded as a pretty good oscillator) has a spec of
> 4.5E-9 over 70C which is 6.4E-11/C. If I'm reading my notes correctly,
> that tbolt oscillator measured at 1.4732E-10 parts/C... about 2.3 times
> worse than a 10811A.
>
> Generally Thunderbolt oscillators have rather crappy tempcos. There has
> been a lot of talk about them being double oven units, but I seriously doubt
> that. They make pretty good T to F converters...
>
> Note that some of the tempco could be due to the power supply, it is outside
> of the temperature controlled box. A previous test indicated that about 1/3
> of the tempco was due to power supply variations)
>
> Those temperature cycles in the graph are +/- 10 millidegrees... the
> oscillator should be moving 3 parts/trillion over the cycle (assuming no
> thermal lag). Such a small change shows up very clearly in the self-reported
> OSC error data from the Thunderbolt.
>
>
> --
> The oscillator tempco shown on the screen is -1.6 ppb per degree C. 1/10 of
> that would be 0.16 ppb/C. I would hope that the oscillator in your
> Thunderbolt is much better than that.
>
>
> _
> Hotmail: Free, trusted and rich email service.
> http://clk.atdmt.com/GBL/go/171222984/direct/01/
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
