Yes, I cross-connected the pins, but I didn't cut any short.
On Wed, Nov 22, 2017 at 11:36 PM, Bob kb8tq <[email protected]> wrote: > 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 <[email protected]> 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 <[email protected]> wrote: > > > >> Hi > >> > >> > >> > >>> On Nov 22, 2017, at 5:16 PM, Jerry Hancock <[email protected]> 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 -- [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. > _______________________________________________ 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.
