Hi For checking things like GPSDO's the pps is actually much more useful than the 10 MHz. Just do the count one to the other trick and you have a very good way to test what's going on. In it's normal configuration it should tune to within about 1 ppt of the proper frequency. That would be 10,000,000 Hz / 1,000,000,000,000 or 1 ns every thousand seconds on the pps.
Bob On Sep 17, 2013, at 8:37 PM, Bob Stewart <[email protected]> wrote: > Hi, > > I'm just looking for an accurate standard for my GSPDO PLL coding. As it is, > I've been depending on others who have these to tell me the code works. I > understand that when these are retuned to 10MHz, they're .005Hz off due to > the DDS. I'm good with that. =) > > Bob > > > > > >> ________________________________ >> From: Bob Camp <[email protected]> >> To: Discussion of precise time and frequency measurement >> <[email protected]> >> Sent: Tuesday, September 17, 2013 7:30 PM >> Subject: Re: [time-nuts] My FE-5680A Came In Today >> >> >> Hi >> >> Keep in mind that these things make a pretty awful 10 MHz standard. They are >> spur monsters in a big way. They won't drive your counter nuts, but for >> anything that wants signal purity - watch out. >> >> Bob >> >> On Sep 17, 2013, at 8:14 PM, Bob Stewart <[email protected]> wrote: >> >>> Hi Bob, >>> >>> Yeah, I figured that retuning it would lose the 1PPS. No biggie. There >>> are a number of those little connectors in this device, and the two that >>> have cables connected use a flat 90 degree connector with a coax that's a >>> bit smaller than RG-174. I just want to snap a pigtail on it and lead it >>> out through a notch in the cover where the DB-9 connector is. There are >>> several examples on the web where people solder wires to the connector and >>> to the RS-232 header. I'd just as soon avoid soldering wires if I can. >>> >>> Bob >>> >>> >>> >>> >>> >>>> ________________________________ >>>> From: Bob Camp <[email protected]> >>>> To: Discussion of precise time and frequency measurement >>>> <[email protected]> >>>> Sent: Tuesday, September 17, 2013 7:06 PM >>>> Subject: Re: [time-nuts] My FE-5680A Came In Today >>>> >>>> >>>> Hi >>>> >>>> If you retune it, you probably will throw off the pps. The pps drive >>>> strength is a bit weak, so you need to be careful looking for it. On some >>>> units there is a software command to enable / disable it (as in pps only >>>> when warmed up and locked - like a gps). The can / cover on the unit is mu >>>> metal (Rb's are mag sensitive). If you drill a hole in it, you are likely >>>> to impact it's mag shielding properties. >>>> >>>> Bob >>>> >>>> >>>> On Sep 17, 2013, at 6:21 PM, Bob Stewart <[email protected]> wrote: >>>> >>>>> My FE-5680A Rb standard came in today. After the usual inspections etc, >>>>> I fired it up and I have the purple haze. The native output is >>>>> 8.38860798/9 (last digit jitter) as read on my 5335A using my GPSDO as an >>>>> external standard. I've got a ways to go before it's all setup, but this >>>>> is looking good. Does it warmup and change frequency at all, or can I >>>>> retune it to 10MHz and use it as a reference without any further ado? >>>>> >>>>> Can someone tell me what type of socket that is where you tap off the RF? >>>>> It looks sort of like a uFL connector, but a bit bigger. I'd rather >>>>> avoid hacking and soldering on this if I can. >>>>> >>>>> Bob - AE6RV >>>>> _______________________________________________ >>>>> 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. _______________________________________________ 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.
