Hi The Efratom “big” Rb’s are sort of an early version of the telco devices. Their design dates back well before the smaller units came out. There also are very similar devices made by EG&G ( we wanted a part of that market, back in the day ….).
Bob > On Dec 11, 2021, at 10:59 AM, Wilko Bulte <[email protected]> wrote: > > hi Paul, Bob, > > Is there a significant difference between these telco-surplus Rb and the more > 'fancy' ones in this regard? > > I happen to own an Efratom MRK-HLN, which, I presume, is also more geared > towards "always on". So, I wonder would the MRK be better or worse compared > to a telco-surplus unit? Arguably a telco-surplus unit is also of the > always-on variety or? > > best, > Wilko > (newbie trying to get a feel for this) > >> On 11 Dec 2021, at 16:27, paul swed <[email protected]> wrote: >> >> Totally agree with Bob. Same experience. >> >> >>> On Sat, Dec 11, 2021 at 8:12 AM Bob kb8tq <[email protected]> wrote: >>> >>> Hi >>> >>> Yes, that’s pretty normal operation for any of the telecom Rb’s. They >>> also typically drift about 1x10^-9 over the first day of operation. It’s >>> best to leave them running all the time. Second best is to turn them >>> on a couple days before you need to use them. >>> >>> Bob >>> >>>>> On Dec 11, 2021, at 2:23 AM, Erik Kaashoek <[email protected]> wrote: >>>> >>>> My rubidium frequency standard (Accubeat AR60A) finally got its nice box >>> with good cooling and some LED's showing the status. >>>> While watching the unlock LED I noticed the AR60 say's it is locked, >>> about 4 or 5 minutes after cold start, when the frequency error jumps below >>> about 1e-8 >>>> It takes 2 or 3 more minutes of slow drift to become stable within >>> 1e-10. Is this to be expected? >>>> With this locking speed it is tempting to switch off the AR60A unless >>> needed for some measurement. Would daily switching on/off have any impact >>> on lifetime? >>>> _______________________________________________ >>>> time-nuts mailing list -- [email protected] -- To unsubscribe >>> send an email to [email protected] >>>> To unsubscribe, go to and follow the instructions there. >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] -- To unsubscribe send >>> an email to [email protected] >>> To unsubscribe, go to and follow the instructions there. >> _______________________________________________ >> time-nuts mailing list -- [email protected] -- To unsubscribe send an >> email to [email protected] >> To unsubscribe, go to and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- [email protected] -- To unsubscribe send an > email to [email protected] > To unsubscribe, go to and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
