[time-nuts] Rubidium stability

WB6BNQ wb6bnq at cox.net
Sun Apr 29 22:09:44 UTC 2007


Jerry,

Do you have a heat sink mounted to the Rb source ?  It sounds, possibly, like a
heater not reaching equilibrium.

Didier's suggestion of comparing against WWV would be a good start to find who is
at fault.  Your counter time base may have an unknown problem.

Bill....WB6BNQ

Didier Juges wrote:

> Jerry,
>
> 80 Hz is much more than either device should exhibit. There is something
> seriously wrong, and if you have a short wave receiver that can receive
> WWV at 10 MHz (AM is fine), you should try to listen to the beat
> frequency between WWV and either oscillator. That will tell you which is
> off.
>
> You may have to use a small piece of wire plugged into the BNC of either
> oscillator as an antenna. adjust the length and/or separation with your
> receiver to adjust the level so that you hear a beat frequency with WWV.
>
> Alternately, try to borrow a known good counter from someone local. In
> either case, an oscilloscope would help check the outputs. When an
> oscillator is way off in frequency, the signal may not look right on the
> scope.
>
> Didier
>
> JOS Earthlink wrote:
> > Hi Group,
> >
> > I'm a newbiew and just bought a Lucent RFG-RB rubidium source on Ebay from a
> > reliable seller.  I am observing a daily variability of about 80Hz and
> > hourly variability of a few Hz with a calibrated HP 5334B counter (with oven
> > oscillator option).  The counter and rubidium source have been powered on
> > for over a week in my basement workgroup which has a stable ambient
> > temperature.  I'm using a cannnibalized power supply from an HP-5328A (all
> > the caps replaced) for the 24v rubidium power source ... its supposed to be
> > a quite stable PSU.
> >
> > Is this variability more likely due to the rubidium source (failing bulb) or
> > due to problems with the 5334B counter?
> >
> > Any advice appreciated.
> >
> > Jerry
> > K1JOS
> >
> >
> > _______________________________________________
> > time-nuts mailing list
> > time-nuts at febo.com
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> >
> >
>
> _______________________________________________
> time-nuts mailing list
> time-nuts at febo.com
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts





More information about the Time-nuts_lists.febo.com mailing list