); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] Magnus Danielson wrote: > Hej Bruce, > > >> Oscillation/cycling of oven temperature? >> Oven controller oscillation? >> > > Might be, but then my "loadingcondition" has caused the oven control out of > stability. This would certainly supprice me. The oven control in the 10811 is > linear and for most practical purposes behave like a first-degree linear > diffrential system. OK, there might be a second degree aspect, but the poles > should be fairly stable and it would be more a pure "amplitude" problem. > > Now as I was down putting the hood on (and removing some of the residues from > the not so very smart packaging, using isopropanol) the down-spikes had > started > to become fewer and rare, and it had 490 uHz of Allan Deviation, i.e. 4,9E-11 > for tau = 5 s. I beleive it will considerably lower as the spiking stops. > > The full 10811 seems powered during standby mode. Some solutions will only > have > the oven powered in standby. What does change on powerup of the rest of the > counter is that you turn on alot more heat, current, the fan (which has a fat > metall wall between the flow and the 10811, but that piece of metal wrapps the > 10811 so the cool-of-effect may be there never the less. > > After putting the lid on and letting it sit there the spikes is still evident > and last reading gives 5,8E-11 @ tau = 5s. > > A comperative measure with another 10811 (which I just *happend* to have a > cable for lying around on the table) but which was unheated also gave time for > a little experiment, looking at the heat-up performance. Now, it started some > 200 Hz hot, but went for a steady linear dive downwards which at about 400 s > curved upwards and had a gentle overshot (i.e. lower frequency) until it > stablized. However, subsequent measure showed a slow but steady rise and ADEV > measures was surely limited by the driftrate. It was however much lower, such > as 1.2E-11, and that includes the drift-rate tainting while the display > indicated a much smoother curve. > > As I don't have a wiring aisle for my lab-bench (beleive me, I start to > consider it as a must have even if it would be a squeeze-in variant of 3-4 > dm or so, I could not get the heated 10811 in my 5372A. I really need to hook > the backside panels up to a BNC patch any decade now. Anyway, otherwise I > would > have a well heated alternative to measure on. > > I wish I get a phonecall with good news from a fellow time-nut tomorrow. If so > I drive down to him. :-) > > Cheers, > Magnus > > Hej Magnus
What I had in mind was perhaps a bad joint or component failure in the oven regulator due to thermal cycling and or age of the oscillator. Perhaps the oven regulator compensation capacitor?? Bruce _______________________________________________ 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.
