Thanks, Rex. Does anyone know how these two units work together? I assume it must be for redundancy, but it's hard to figure out just how it all works together. I assume the Rb is intended to provide long-term holdover if the GPS or XO fails. It'd sure be nice to find at least some system-level documentation.
John ---- Rex said the following on 12/28/2006 03:22 AM: > I just received a Lucent RFG-RB (no -m- in this one) rubidium unit eBay > buy from the lady in Atlanta. Thought I'd share a few notes on what it > is. Maybe some of this has already been covered -- I lost track of all > the emails. > > Like John, I immediately opened it up, haven't tried it yet, and won't > for a while. > > No GPS, as has been noted in the other messages, that seems to be in the > crystal unit. This one was made in 2000. Inside mine, the main component > is a Datum LPRO 102500. Seems to be functionally identical to the one in > the manual here: > http://www.symmetricom.com/media/pdf/manuals/man-lpro.pdf > > Box front panel: > 3 sma's - TP (J1), 10 MHz RF Out (J2), 15 MHz Out (J4) > 3 db9's - +24V (P1), Alarm (J3), Interface (J5) > 3 led's - Fault, Stby, On > > Seems the +24V connector only uses two pins: 1 = +24, 2 = return/gnd > I assume those two are all that's needed to make it run. > > Main board is made by Efratom. > > I don't see any connection to the rubidium C-field pin so I don't think > there is any adjustment through the main board, just the adjustment thru > the case of the LPRO. > > With some tracing, I can't figure where the 10 MHz output (sma) comes > from. I assume it is functional, but haven't applied power yet. > > The 15 MHz generation looks very similar to the other boad I described > in another message on an FRS-C unit. The active source again seems to > come from an Altera PLD. Maybe it divides 10 MHz by two, and (guess) > narrows the pulse for better 3rd harmonic? Anyway, then it seems to go > through a series resonant LC, with a trimmer on the C. Then thru the 15 > MHz filter, two stages of amplification, and a MCL low-pass filter to > the sma. > > BITE signal from the LPRO goes somewhere so I assume it is at least part > of the alarm connector output. > > If anyone finds or works out the pins on the alarm and interface > connectors, I'd eb interested to hear about it. > > So there we are for now. Quick first look without even trying it yet. > Assuming it works, the LPRO was probably worth my $130 investment. Hope > some of my comments helps someone. > > -Rex > > > _______________________________________________ > time-nuts mailing list > time-nuts@febo.com > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts