Hi I have run a number of the REF0 / REF1 combos. They all seem to work fine. The standard cable has some odd short pins on it. If you are not hot plugging the cable I don’t think they matter at all. If anything, the system is more reliable with a normal length pin on the connector.
Bob > On Nov 22, 2017, at 6:08 PM, Adrian Godwin <artgod...@gmail.com> wrote: > > I've got several of the Ref 0 boxes but none of the Ref 1. I've added an > Oncore GPS receiver to one of them as per Peter Garde's notes and it works > well. > > But I'd like it to run with an unmodified Ref 0 too in the ref0/ref1 > configuration. Not that I need an HA reference but just for interest. I've > only had a quick look so far and found that connecting the two together > with a 15-pin cable didn't work. > > Has anyone looked into this ? > > > On Wed, Nov 22, 2017 at 11:01 PM, Bob kb8tq <kb...@n1k.org> wrote: > >> Hi >> >> >> >>> On Nov 22, 2017, at 5:16 PM, Jerry Hancock <je...@hanler.com> wrote: >>> >>> Three questions: >>> >>> 1) Now that I’ve split my Lucent RFTG-U into a REF0 and REF1 unit with >> both supplying 10Mhz and 1PPS, is there a way to combine the outputs or >> some other technique to improve the short and/or long term performance? >> >> You can monitor one against the other. Ideally you would want three >> GPSDO’s and a >> monitoring setup. That way you can figure out which of the three has gone >> bad. >> >>> >>> 2) I’ve become interested in Rubidium Disciplined Oscillators recently >> and was now thinking of purchasing one of the PRS-10 that I see on Ebay. If >> I did that and replaced one of the DOCXOs from one of the Lucent boxes, >> what impact would this have on the overall performance both with and >> without (when in hold-over)? >> >> If you go into holdover, you are the exception. Most setups rarely go into >> holdover. When they >> do, it’s because a hurricane just went over the house. Generally that’s >> not when the focus is going >> to be on timing experiments. >> >>> Basically, is it worth the money to upgrade one of the boxes to a >> Rubidium disciplined oscillator assuming the GPS signal is rarely lost? >> >> Not worth the money if you are only looking at holdover and have a typical >> setup. >> >>> >>> 3) Figuring the PRS-10 will cost around $250 when all is said and done, >> is there a better option to improve my GPSDO system? >> >> >> Disciplining implies continuously correcting. Rb standards age much less >> than a typical >> OCXO. Oddly enough their temperature stability may not be as good as a >> high end >> DOCXO. It is fairly common to try to stabilize the environment your >> standards operate in. >> To the extent you are successful this reduces the need to deal with >> temperature. >> >> The net effect is that disciplining an Rb at a rate (filter / control loop >> / manual tweak) of less than >> a few days actually makes the Rb worse. Coming up with software to “back >> off” on the tuning is >> not as simple as it might seem. >> >> This comes back to the fact that the GPS signal (or any of the sat >> signals) are quite noisy. You >> need to average them over a *long* time to get good performance. Rb’s are >> enough better than >> a GPSDO OCXO that the time ranges really stretch out …. >> >>> >>> I basically use the GPSDO as a reference for any equipment that takes an >> input. I have no monetary need for a reference, just an interest. >> >> For most normal test equipment, a GPSDO output is “plenty good enough”. As >> a source for fancy >> timing experiments … maybe not so much. As a phase noise reference or a >> spur free source for >> microwave games … also not the best way to go. >> >> Bob >> >> >>> >>> Thanks. >>> >>> Jerry >>> >>> _______________________________________________ >>> 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. >> >> _______________________________________________ >> 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. >> > _______________________________________________ > 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. _______________________________________________ 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.