John Thank you for your effort. It would be nice if you could confirm the 4 to 5 Hz dither that seems to be the loop time constant and long term aging that will influence the GPS/Rb control loop time constant setting. I did see 1 E-12 per month which may be unique to that unit. Bert Kehren In a message dated 2/3/2012 10:19:47 P.M. Eastern Standard Time, [email protected] writes:
> Someone earlier today made the point that for all the talk about the FEI > rubes, there hasn't been any real performance info posted. That prodded > me to start an experiment I've been meaning to do for a while. I have > samples of all three of the common telco Rb standards -- Efratom FRS, > Datum LPRO, and Fe8-5680. > > Over the next couple of days I'll do measurement runs of each of the three > versus an HP-5065A laboratory Rb (for ADEV), and a Wenzel ULN (for phase > noise). I'll collect long enough to get solid ADEV out to at least 1000 second > tau on each unit. I have the FRS test running now. > > If all goes well, I'll post the results early next week. I'm doing some short-term runs on the ones I have around here, as well (FE-5680A, PRS-10, LPRO). Will be interesting to see how close ours are. So far, the FE-5680A is doing well in the ADEV department, but its AD9832 DDS chip adds some substantial noise and spurs to the 10 MHz output. Does yours have that chip? I understand that some of them didn't. The overall SSB C/N ratio I'm seeing between 1 Hz - 100 kHz is pretty much in line with Analog Devices' data sheet, as are the spur levels. -- john _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
