Hi The oven in the OCXO keeps the crystal at a constant temperature. It is normal for the TBolt it's self to idle 10 to 20C above ambient. The temperature sensor is located near the 9 pin D connector. It shows a temperature somewhere in between the ambient and the OCXO case temperature. Some have mounted speed controlled fans to keep the TBolt case at a constant temperature.
Bob On Dec 10, 2012, at 5:15 PM, Sarah White <[email protected]> wrote: > Ended up with a gently used trimble thunderbolt a few months ago, and > been trying to figure out the best settings to use (time constant, > damping, etc.) for best performance. > > I got distracted though. There is something which I find rather > annoying, and I'm spending more time messing with this factor than > actually observing the performance at different damping / time constant > / etc... > > The temperature seems to be aprox 20C above ambient temperature rather > than a steady 40C. I thought the purpose of the oven was to keep the > temperature stable. When I adjust the thermostat because I'm chilly, the > thunderbolt gets warmer too (but not by as much) > > I've tried (seemingly, to me) everything: > > light insulation > > putting the unit in a spot away from drafts > > putting the unit in a place away from drafts in a shoebox with light > insulation with a fan blowing in it (currently in a cupboard in this > state, and the temp seems to fluctuate the least, but still by more than > 1-2 degrees centigrade) > > I feel like shouldn't need to fuss with ambient conditions this heavily > for an OCXO, and find myself researching construction / design for a DIY > outer-oven to wrap the thunderbolt in. > > Anyone have experience with non-stable temperature on a trimble thunderbolt? > > I've also noticed (monitoring with Lady Heather's Disciplined Oscillator > Control Program v3.10 by John Miles aka KE5FX) the thunderbolt unit > sometimes flags an alarm briefly (and I rarely ever manage to write it > down before the screen updates or the alarm goes away) and the last one > I was able to "catch" before it went away was related to temperature. > > Should I be getting a steady / non-flucturating 40C or something if the > oven is working normally? > > Thanks in advance, > Sarah > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
