[time-nuts] Thunderbolt - temperature
didier at cox.net
Fri Jul 11 18:37:55 EDT 2008
Monitoring the crystal temperature would probably be extremely boring. I
would expect it to be absolutely stable, as far as the internal TB
temperature monitor is capable of displaying it.
Monitoring the electronics temperature is useful because it relates to the
ambient and allows you to plot the dependancy of frequency to ambient, and
indirectly verify that the air conditioning is working.
Putting the TB in an isolated box may be counterproductive, because the ~10W
of average dissipation has to go somewhere, otherwise the TB will cook
On the other hand, I think it would be very well advised to place the unit
in a quiet area with minimal temperature changes, like you would do to keep
a good bottle of wine.
A while back I plotted the current consumption of an HP 10811 as a function
of ambient temperature in my not-very-well regulated ham shack
(http://www.ko4bb.com/Test_Equipment/HP10811-Current.png). It was as
predicted, considering the ~80 degree operating temperature of the oven.
Keeping the unit at constant ambient reduces the need for the oven to draw
more or less current. No matter how well the oven is decoupled from the
crystal, nothing is ever perfect, so minimizing the ambient variations has
got to be a good thing.
> -----Original Message-----
> From: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Patrick Reynaert
> Sent: Friday, July 11, 2008 1:22 PM
> To: time-nuts at febo.com
> Subject: [time-nuts] Thunderbolt - temperature
> I have a question regarding the temperature reading in the
> Thunderbolt Monitor program of the Trimble Thunderbolt GPSDO.
> Is this the temperature of the board or the temperature of
> the crystal?
> Related to this: does it help to put the Thunderbolt in an
> isolated box or is this an overkill?
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