Hi They are after good ADEV out to the point that the loop bandwidth lets the gas cell take over. In some cases that can be a bit further out than others.
Bob On Aug 27, 2013, at 10:09 PM, Ed Palmer <ed_pal...@sasktel.net> wrote: > Yes, in many of the more recent Rb standards you're lucky if the crystal is > ovenized at all. But are you sure that they're after good ADEV? I get the > impression that the only thing they're interested in is low drift for the > unit (e.g. for holdover purposes) since they're intended to be components in > a system rather than lab standards. Anything else is more luck than intent. > The PRS10 seems to be an exception in that it has an SC xtal. Other than the > 5065A, are there any Rb standards that use an SC xtal? > > Ed > > On 8/27/2013 6:24 PM, Bob Camp wrote: >> Hi >> >> The "OCXO" in most Rb's isn't all that great. They are after good ADEV, but >> tempco and aging aren't terribly important. >> >> Bob >> >> On Aug 26, 2013, at 1:34 PM, Nathaniel Bezanson <mys...@telcodata.us> wrote: >> >>> At room temperature, mine takes about 3-4 minutes heating until the lamp >>> will start. You'll see RbMon showing SD2 and AD4 at max values, then >>> they'll settle back into something sensible once it lights up. After that, >>> you're watching the DS signal values and hoping the (large, small) turns >>> into (small, large). >>> Mine had a blown capacitor in the lamp circuit, thus it wouldn't ignite; >>> SD2 and AD4 never budged. I opened it up to find a cracked tantalum cap: >>> http://imgur.com/bASgB After replacing the cap, I now get lamp ignition but >>> it doesn't achieve lock. (Photocell signal AD9 very low.) Once I swear I >>> saw RbMon claim it had locked, about 6 minutes after power-up, but a moment >>> later it was back to unlocked state and it's never repeated that feat. No >>> idea what happened there. >>> I'm wondering whether one can simply use it as a nice (albeit power-hungry) >>> OCXO. If given 1pps from GPS, will the quartz discipline itself even >>> without the Rb loop running? >>> -Nate B- >>> Stephen Tompsett (G8LYB) wrote: >>>> Use the RbMon utility to monitor the unit's operation as it >>>> starts up to >>>> confirm that the lamp is started and the photocell is detecting a signal. >>>> Not long ago there were a number of units available for sale on Ebay >>>> that appeared to have a lamp problem. >>>> >>>> On 23/08/2013 02:10, Paul wrote: >>>>> As I patiently wait for my PRS10 to lock I'm curious if there's a >>>>> limit beyond which I should assume the unit is faulty. >>>>> >>>>> It does produce abount 10MHz (+- .2 Hz) and the oven current dropped >>>>> at what I assume is operating temperature. >>>>> >>>> -- >>>> Stephen Tompsett (G8LYB) >>>> >>>> > > _______________________________________________ > 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.
