My experience is very similar to Scott's. I ran many hours with both an LPRO-101 and FE-5680A. The disciplining behavior and Fury settings were the same for either Rb. My biggest disappointment was the recovery time due to various common or intentional bumps or especially, after power loss. I also had to let the "system" settle in for a week before acceptable tracking smoothed out. Any long term slope to the EFC trace (gpscon) caused excessive hunting and this didn't settle down until the Rb was VERY stable. My gpscon TI and stddev was virtually the same as Scott's if I had EFCS set to 1.0 to 1.5 but recovery was unacceptable (maybe 24-hours) so I usually ran at 2.0 or 3.0 with slight degrading of stddev to around 3.2. This EFCS setting allowed a much better settling time around 3-hours. DACG= 1000 EFCS = 2 to 3 EFCD = 50 (25 allows little better settling time) PHASECO = 15 (I favor 10 Mhz over PPS) Regards... Don
________________________________ From: Scott Mace <[email protected]> To: [email protected] Sent: Tue, July 27, 2010 10:41:16 AM Subject: Re: [time-nuts] Fury - Rubidium I have done this with several LPRO-101, X72, and a FRS-C. The FRS-C that I used was out of a Lucent RFG-RB box. It had a hot TTL output that was causing issues with the Fury, The level was the problem, not the ttl. The EFC was hypersensitive, and it took a long time for the unit to settle down before the Fury would handle it. Same thing with the LPRO, and X72, you have to wait for it settle for a week or so before it starts to work well if it's been off for a long time. The X72 was by far the worst, and it would jump from time to time, which would make the fury unhappy. I didn't have a chassis that would fit the FRS-C and the fury, so I just went back to the LPRO. The lpro-101 has been the best so far. I put everything in a 1U chassis and placed it in the bottom of my rack away from the AC vent. This is what I use with the LPRO-101. dac gain: 1000 efc scale: 1.30 efc damping: 35 ocxo slope: positive phaseco: 35 I test it by changing the antenna delay. It should recover within a reasonable time. Bumping the coarsedac is typically too much change and takes longer to recover. I run it with a 20ns offset to my z3801a, and they always stay within 20ns of other. I've had the Fury running for about 5400 hours since the last reboot, running v1.21 firmware. It stays within +-10ns, usually it's between +-5ns. Over 24hrs, gpscon reports TI average 0.15 or so and stddev around 2.5ns. Scott On 7/27/2010 9:07 AM, Brian Kirby wrote: > Has anybody on the list interfaced a Fury GPS controller to a rubidium ? > > If you have, please advise the rubidium are using and your SERV:DACG , > SERV:EFCS , and SERV:EFCD settings. > > I am working with a FRS-C at the moment and I have not found the right > combination to get a stable lock. > > Thanks - Brian KD4FM > > _______________________________________________ > 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.
