[time-nuts] Lucent GPS "RFTGm-II-Rb"

Brian Kirby kirbybq at bellsouth.net
Tue Sep 20 15:59:20 EDT 2005

We'll - 48 volts is the nominal central office supply voltage.  If you 
can open it up and see if the unit has a main power supply, you may look 
at the ratings of the main capacitor - it may give you a clue.

Charles S. Osborne wrote:

>Wonder if anyone on the list has information about a Lucent Rubidium locked
>to GPS unit I have? Its relatively new, maybe five years old. Purportedly to
>be from a failed cell site venture that caused the unit to be sold surplus
>having never been installed. The nomenclature on it is:
>Lucent: KS-24019 L109  which I assume may be an in house part number or
>contract number.  The model number is:  RFTGm-II-Rb .
>I've posted some pictures at:
>The unit comes up and locks an OCXO to GPS. Then after some more warm up
>time it switches over to the locked Rubidium side and the OCXO switches to
>become the standby.
>My problem with it is that when I come back the next day the Rb side has
>faulted out and pushed the system back onto the OCXO as the main online 10
>MHz source. Its unlikely the Rubidium lamp is old enough to be a problem, or
>that the initial frequency adjustment has drifted out of range.. though I
>suppose its remotely possible.
>Have been running the unit on 24vdc but would try more if I thought the
>normal -48 ~ 56vdc telco battery strings were used with this. It gets warm
>enough on 24vdc that I didn't want to chance it until I asked. I know if its
>a switcher that it might actually run cooler on higher voltage due to a
>proportionate drop in current. Just haven't had a chance to reverse engineer
>it all.
>I see RS422 labeling on some  of the ports. But without more info I'm
>proceeding with caution and somewhat at a standstill as to what's going on.
>Anyone have any experience with these units?
>Charles S. Osborne, K4CSO
>Technical Director
>Pisgah Astronomical Research Institute
>1 PARI Drive, HC 73, Box 638
>Rosman, NC 28772-9614
>828-862-5813 direct
>828-862-5554 main
>828-862-5877 FAX
>cosborne at pari.edu
>time-nuts mailing list
>time-nuts at febo.com

More information about the time-nuts mailing list