>...is the fact that the GPS is very temp sensitive...< What have you observed, out of the GPS, with the temperature variations?
On Sat, Dec 13, 2014 at 6:08 PM, <d...@irtelemetrics.com> wrote: > Hi Alex, > Monitoring the temperature control loop of this OXCO is even easier than > that. Currently instaled is a HP10811. It has a very handy oven monitor pin, > that varies voltage with what the control does to keep temperature constant. > (Those HP guys were really thinking!) Any time the oven has to react to > something it's visible on that pin. Albeit, most of the stuff is in the > 100uV or under level, but it's there. > Currently there is a 8Ch 24bit DAQ card tied to this whole thing, and the > card has proven to be more than stable enough to see what's going on. There > is some correlation between the bulk supply voltage and DAC/Phase, so the > next step is to chase that down. Just not exaxtly sure how it's getting in > there. It's interesting what can be learned from looking at a bunch of > data... The really interesting thing is what's going on with the GPS > temperature. You can see it ramp temp slowly, then drop 1/2 deg F, then ramp > up slowly, and drop again. One would guess that it's tied to CPU load or > similar. The only thing that bothers me about that, is the fact that the GPS > is very temp sensitive. It may very well be the limiting factor. I have yet > to monitor the VCC to the GPS, so there might be something more to learn... > 73, > Dan > > > > > > just thinking; OXCO is one ovenized crystal oscillator with temperature > > control, better to say temperature stabilizer, thus if the outside > > temperature changes the control loop shall keep the internal temperature > > constant-- by definition, > > the function of the temperature control loop could be observed by the > > variation of the supply current of the oven. Also the reference voltage > > supplied from inside of the OCXO is coming from a voltage source which > > has stabilized temperature, therefore it is "a relative stabil reference > > voltage source", which could be used to compare the stability of other > > voltages and thus, it could be found which voltage is moving with the > > environment's temperature. > 73 > > Alex > > _______________________________________________ > 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.