I just noticed that the ripples in the phase plots are the slow cycle at about 1/10Hz. Also, I'm pretty sure the power supplies are not the problem as the frequency of the ripples between the two 10811 units are slightly different. Skip Withrow

Hi Skip; Could be cabling picking up your other reference at a slightly different freq. Cheers; Tom Knox SR Test and Measurement Engineer Phoenix Research 4870 Meredith Way Apt 102 Boulder, Co 80303 Formerly of: 357 Fox Lane Superior Co 80027 303-554-0307 actast@hotmail.com https://www.thedenverchannel.com/news/marshall-fire/superior-man-moving-forward-after-losing-dream-research-lab-during-marshall-fire "Peace is not the absence of violence, but the presence of Justice" Both MLK and Albert Einstein ________________________________ From: Skip Withrow via time-nuts <time-nuts@lists.febo.com> Sent: Monday, February 27, 2023 9:14 PM To: time-nuts@lists.febo.com <time-nuts@lists.febo.com> Cc: Skip Withrow <skip.withrow@gmail.com> Subject: [time-nuts] 10811 behavior - addendum I just noticed that the ripples in the phase plots are the slow cycle at about 1/10Hz. Also, I'm pretty sure the power supplies are not the problem as the frequency of the ripples between the two 10811 units are slightly different. Skip Withrow _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-leave@lists.febo.com

> -----Original Message----- > From: Skip Withrow via time-nuts [mailto:time-nuts@lists.febo.com] > Sent: Monday, February 27, 2023 8:15 PM > To: time-nuts@lists.febo.com > Cc: Skip Withrow > Subject: [time-nuts] 10811 behavior - addendum > > I just noticed that the ripples in the phase plots are the slow cycle at > about 1/10Hz. Also, I'm pretty sure the power supplies are not the problem > as the frequency of the ripples between the two 10811 units are slightly > different. > Skip Withrow Looks like a beatnote artifact. They are tough to avoid once you get down into the 12s. Check the 10811's frequency offset from 10 MHz to see if it coincides with the beatnote period; it probably will. Tips: 1) Hit 'n' and use the notch filter to identify and remove the tone. This can take some fiddling. 2) Make sure the connection integrity is rock-solid. Even the smallest pigtail in open air will couple to the primordial 10 MHz background radiation we all have floating around. Don't lift the coax grounds at either end. 3) Cables should be of good quality and no longer than necessary. As a proxy for cable leakage, measure the shield's DC resistance from one end to the other. If it isn't << 1 ohm, it's asking for trouble. 4) Re-run the measurement after tweaking the 10811's frequency to bring it in line with your reference. Adjust the frequency in situ with your DMTD, so the load is the same. -- john

Hi Since the others have chimed in on beat notes, I’ll poke at the power supply stuff. One really fun aspect of an oven controller is that it can indeed cycle without the power supply being defective. Put a dozen or so parts on a test fixture and feed them through a skinny piece of wire. You likely will get them all cycling. The gotcha is that a defective contact can do pretty much the same thing as that skinny wire. A failure of a component in the controller that boosts it’s gain also can put it into the same sort of cycling. Spotting this is pretty easy. Look at the current meter on the power supply. It will be cycling as the ovens do their thing. If it isn’t, cross this off the list. No, this would not be my first guess, still it is a possibility. Bob > On Feb 27, 2023, at 11:14 PM, Skip Withrow via time-nuts <time-nuts@lists.febo.com> wrote: > > I just noticed that the ripples in the phase plots are the slow cycle at > about 1/10Hz. Also, I'm pretty sure the power supplies are not the problem > as the frequency of the ripples between the two 10811 units are slightly > different. > Skip Withrow > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com

Bob: I've forgotten, if I ever knew, whether the oven(s) on these devices are bang-bang controllers or linear controllers? Don On 2023-02-28 06:41, Bob Camp via time-nuts wrote: > Hi > > Since the others have chimed in on beat notes, I’ll poke at the power > supply > stuff. > > One really fun aspect of an oven controller is that it can indeed cycle > without > the power supply being defective. Put a dozen or so parts on a test > fixture and > feed them through a skinny piece of wire. You likely will get them all > cycling. > > The gotcha is that a defective contact can do pretty much the same > thing as > that skinny wire. A failure of a component in the controller that > boosts it’s gain > also can put it into the same sort of cycling. > > Spotting this is pretty easy. Look at the current meter on the power > supply. > It will be cycling as the ovens do their thing. If it isn’t, cross > this off the list. > > No, this would not be my first guess, still it is a possibility. > > Bob > >> On Feb 27, 2023, at 11:14 PM, Skip Withrow via time-nuts >> <time-nuts@lists.febo.com> wrote: >> >> I just noticed that the ripples in the phase plots are the slow cycle >> at >> about 1/10Hz. Also, I'm pretty sure the power supplies are not the >> problem >> as the frequency of the ripples between the two 10811 units are >> slightly >> different. >> Skip Withrow >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe send an email to time-nuts-leave@lists.febo.com > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com ------------ "It's always something." Roseanne Rosannadanna ----------------------" Dr. Don Latham AJ7LL PO Box 404, Frenchtown, MT, 59834 VOX: 406-626-4304

Hi They are full up linear controllers. They even have a bit of an integrator on them. Bob > On Mar 1, 2023, at 1:55 PM, djl via time-nuts <time-nuts@lists.febo.com> wrote: > > Bob: I've forgotten, if I ever knew, whether the oven(s) on these devices are bang-bang controllers or linear controllers? > Don > > On 2023-02-28 06:41, Bob Camp via time-nuts wrote: >> Hi >> Since the others have chimed in on beat notes, I’ll poke at the power supply >> stuff. >> One really fun aspect of an oven controller is that it can indeed cycle without >> the power supply being defective. Put a dozen or so parts on a test fixture and >> feed them through a skinny piece of wire. You likely will get them all cycling. >> The gotcha is that a defective contact can do pretty much the same thing as >> that skinny wire. A failure of a component in the controller that >> boosts it’s gain >> also can put it into the same sort of cycling. >> Spotting this is pretty easy. Look at the current meter on the power supply. >> It will be cycling as the ovens do their thing. If it isn’t, cross >> this off the list. >> No, this would not be my first guess, still it is a possibility. >> Bob >>> On Feb 27, 2023, at 11:14 PM, Skip Withrow via time-nuts <time-nuts@lists.febo.com> wrote: >>> I just noticed that the ripples in the phase plots are the slow cycle at >>> about 1/10Hz. Also, I'm pretty sure the power supplies are not the problem >>> as the frequency of the ripples between the two 10811 units are slightly >>> different. >>> Skip Withrow >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@lists.febo.com >>> To unsubscribe send an email to time-nuts-leave@lists.febo.com >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe send an email to time-nuts-leave@lists.febo.com > > ------------ > "It's always something." > Roseanne Rosannadanna > ----------------------" > Dr. Don Latham AJ7LL > PO Box 404, Frenchtown, MT, 59834 > VOX: 406-626-4304 > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com