Hi The Rb may or may not have moved onto the walls. The lamp (as designed) may or may not have a well……
Bob > On Sep 28, 2020, at 11:35 AM, David C. Partridge > <[email protected]> wrote: > > What about using a the hot-air gun technique to migrate the Rb from the walls > of the lamp back to the well? > > David > > -----Original Message----- > From: time-nuts [mailto:[email protected]] On Behalf Of Bob > kb8tq > Sent: 28 September 2020 14:23 > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Symmetricom XPRO rubidium > > Hi > >> On Sep 27, 2020, at 10:19 PM, Stewart Cobb <[email protected]> wrote: >> >> I have a Symmetricom* XPRO rubidium which appears to be reaching its end of >> life. The very sparse manual says that it sets a "service" flag when the >> lamp voltage reaches 600 mV. When I got it, that parameter was at about >> 540. Several months of continuous runtime later, it's down to about 510. I >> assume this is a measure of light emitted by the lamp, but its label is >> "lamp voltage". >> >> I don't want to lose this Rb, because it seems to be the most stable >> reference in my lab (about 2x more stable with temperature than a PRS10, by >> eyeball). >> >> Questions for the hive mind: >> >> (1) Why and how is the lamp voltage falling? What's the wear-out >> mechanism? > > It’s looking at the photo detector on the physics package. The amount of > light getting to the photo detector is “getting low”. Once it gets low enough, > the SNR degrades. At some point that gets bad enough for the device to > loose lock > > >> >> (2) Is there any hope of repair? Will the heat gun trick for the LPRO work >> on the XPRO? Could I replace the XPRO lamp bulb with one from a young LPRO? > > The devices are “aligned” to match up with the bulb. The various tweaks to > get that > done are never documented on the Telecom Rb’s. You might get lucky, you might > not. > > If you have a working LPRO, there’s no real reason to expect the XPRO to work > any better than the LPRO ( at least not after surgery ….). > >> >> (3) Has anyone ever done surgery on an XPRO? Any hints or tips? >> >> (4) Does anyone know anything more about the XPRO? I have data sheets >> 900-00542-000B and -000F, and manuals 098-00058-000 rev A and rev B. The >> manuals are just barely sufficient to get the thing running. The device >> itself displays parameters on its serial interface which appear to be >> adjustable but which are not described in the manual. > > Sparse manuals are pretty much the way things are done these days. That’s not > just an issue on Rb’s … > > Best approach is to start shopping ….. > > > Bob > > >> >> Thanks in advance for any help. >> >> *Symmetricom has been acquired at least twice since this device was built. >> But the device label says Symmetricom, and the manual says Symmetricom, so >> I'll stick with that name for now. >> >> Cheers! >> --Stu >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
