Jean-Christophe Deschamps wrote: > Dear group, > > I'm a newbie here, so please bear with me. > > I'm about to buy a FEI 5680A Rubidium frequency standard off > ebay. From what I've gathered, these units were used in the telco > industry for about 10 years, but are still useable for my needs. I > wish to have a reasonably good frequency standard for calibrating test > equipment (scope calibrators, function generators, etc), say every 6 > months or once a year. For such use I really don't need extreme > stability/accuracy. Only hope is that the physics part isn't > completely dead. > > These units typically only produce a 1pps signal, but have the capacity > to produce the classical 10 MHz sine wave. > > I've found a number of documents explaining how to have the 10 MHz > produced by these versions. Two of them give consistent informations > and seem to be sufficiently documented to be of real value. > > Drop me a mail at [EMAIL PROTECTED] if you feel posting the files could > help someone. I don't know how to post files so that readers of this > list can access them. Anyway, I'll postpone distributing the files at > large until I check by myself their contents is useful. > > Feedback welcome! > > It seems there were many versions of the 5680A that look about the same but are very different. Some run on just +15 V and some need that and +5V. I suspect there are other voltage options too. Some are adjustable in frequency with software commands or a C-field screw.
I bought one in early 2005. I figured out by reverse engineering that it needed both +15 and +5 V. It provides both 10 MHz and 1pps outputs on the D-connector. I never found a way to get it to respond to any serial commands, although it has rs-232 interface chips and the signals were propagating inside. I never found any way to adjust the frequency on this one. Other people clearly have units that run on just +15V and do respond to serial commands to set the frequency. One person reported they were able to adjust the frequency on theirs with a screw setting. So it is hard to say what you may get. You may want to search the time-nuts archives, particularly in 2005. _______________________________________________ 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.