In the commercial world a PRS10 is most likely the best but for time nuts even at the surplus price in my opinion it is all hype and a waste of money. Have you looked closely at the specification and the design. Frequency accuracy can not be better than 1 E-12 since the OCXO is driven strictly by a DAC and the A/V is for time nuts nothing to write home about. Any digital loop controlling a Rb in tern with an analog loop controlling a selected HP 10811 or for that matter a Morion will outperform a PRS 10. I have a FRK-H controlling a HP 10811 that has an A/V below 1 E-12 from 1 to 100 seconds, I modified the FRK loop and the 10811. On the 10811 it is easy to get to the bottom PCB and without un soldering any component or further disassembly cutting two traces and two jumpers you end up with a 2 to 12 Volt tuning voltage, perfect for a FRK or M100.. A second option is to use a separate analog loop with a time constant suitable for your OCXO. By the way the FRK-H is not lower noise but factor 2 lower aging with the proper OCXO not an issue, since hopefully you discipline it with GPS. For 12 years I have used Shera in that application recently switching the DAC to a LTC1655. Has served me well over the years. Other Rb's will do also a very credible job. On one extreme a FEI 5680 is waiting to be integrated with a MV180 on the other extreme a HP5065 RVFR assembly will be integrated with a M1000 OCXO along with state of the art circuitry. Bert Kehren In a message dated 8/12/2012 8:09:54 A.M. Eastern Daylight Time, [email protected] writes:
Thanks Tom. I agree, the SRS seems to be the best overall Rb except maybe on old HP if one is willing to spend about the same price on a 20 year old unit. The SRS units I bought for work were only $2700 with chassis, rack ears and multiple outputs. -Brian, WA1ZMS On Aug 12, 2012, at 3:17 AM, Tom Knox <[email protected]> wrote: > > Hi Brian; > There are a few decent rubidium oscillators short term like the SRS but none are great, in my humble opinion you are much better off disciplining a good quartz oscillator off your LPRO. > Best Wishes; > Thomas Knox > > > >> From: [email protected] >> Date: Sat, 11 Aug 2012 21:56:13 -0700 >> To: [email protected] >> Subject: [time-nuts] FRK specs..... >> >> I used to be of the opinion that the Efratom FRK-H was the best of the models of FRK Rb standards for both short-term stability and overall performance. >> >> Is that still true today? >> >> I know there are better solutions for short-term (BVA OCXO) and long term >> (Cs & MASERS). But where to things stack up today? >> >> I'm looking to buy an Rb that's better than my LPROs and other models. >> But I do not own an FRK-H. >> >> Looking for comments, please. >> >> Thanks in advance, >> -Brian, WA1ZMS >> _______________________________________________ >> 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. _______________________________________________ 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.
