Hi Drive the GPS pps into the set input on a flip flop, drive the pps from the FE into the reset input. Use the UC10 to measure the period of the waveform on the Q output. Not super high resolution, but if you are patient, you can get the job done. Bob -----Original Message----- From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of David Sent: Wednesday, March 14, 2012 7:34 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] FE5680A Calibration I picked up a gimpy Beckman UC10 universal counter not long ago for about $10 from Ebay. Even better, I just repaired a Tektronix 7D15 (it has a whole board full of those junk TI integrated circuit sockets which need to be replaced) although you need to leave an entire oscilloscope mainframe on to use it. The advantage of the later is adjustable slope, sensitivity, and triggering. On Wed, 14 Mar 2012 17:50:28 -0400, Bob Camp <lists@rtty.us> wrote: >At least the "don't mess to much with it" part has sunk in. That puts you ahead of most people at this point. > >A usable counter should be a sub $100 sort of thing either at auction or surplus. With some careful shopping it can be a sub $40 item. > >On Mar 14, 2012, at 4:25 PM, "Chris Stake" <stake@btinternet.com> wrote: > >> Hi Bob, >> Thanks for pointing-out the noisy output of the FE5680A. I'll probably try >> to lock a crystal oscillator to it. >> Unfortunately I don't have a suitable counter. >> I was hoping I could use some sort of higher frequency standard but I >> confess I had not really grasped the fact that the unit may well be within >> millihertz of the nominal frequency: too delicate to twiddle with anything >> other than precision equipment and long timebases. >> Kind regards >> Chris >> >>> -----Original Message----- >>> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On >>> Behalf Of Bob Camp >>> Sent: 14 March 2012 16:57 >>> To: 'Discussion of precise time and frequency measurement' >>> Subject: Re: [time-nuts] FE5680A Calibration >>> >>> Hi >>> >>> Do you have a dual channel counter that you can put the GPS into on the >>> "start" and the FE into as the "stop"? The HP 5334, 5335, and 5345 are all >>> examples of this sort of counter. >>> >>> Bob >>> >>> -----Original Message----- >>> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On >>> Behalf Of Chris Stake >>> Sent: Wednesday, March 14, 2012 12:49 PM >>> To: 'Discussion of precise time and frequency measurement' >>> Subject: Re: [time-nuts] FE5680A Calibration >>> >>> Nice idea, >>> But I haven't got a DSO and the persistence of my scope isn't good enough >>> to >>> view 10Mhz sampled at 1pps. >>> Chris >>> >>>> -----Original Message----- >>>> From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On >>>> Behalf Of EB4APL >>>> Sent: 14 March 2012 15:46 >>>> To: time-nuts@febo.com >>>> Subject: Re: [time-nuts] FE5680A Calibration >>>> >>>> My fast approach would be to trigger a scope with the 1 PPS from the GPS >>>> receiver and observe the how the 10 MHz output of your Rb drifts. 1 >>>> full cycle per second is 1 e-7 so you'll need to use an stopwatch to >>>> time long periods when you are fine adjusting . >>>> Building (or buying) a GPSDO allows yo to make the comparison between >>>> both 10 MHz outputs without the jitter in the GPS receiver 1 PPS. >>>> Probably others in this list can suggest more elaborated and convenient >>>> approaches to this. >>>> >>>> On 14/03/2012 16:17, Chris Stake wrote: >>>>> Hello all, >>>>> >>>>> I purchased a FE5680A from a Chinese Ebay vendor. I have connected it >>>> to a >>>>> 16.5V laptop supply, added 7805-based 5V rail and a PMOS Fet switch to >>>> drive >>>>> a LED for the "locked" signal. I can communicate with it using the >>>> excellent >>>>> Fe5680Calibrator software. As received the frequency offset is set to >>>> Zero >>>>> and the unit seems to work well. >>>>> >>>>> I plan to put it into service as a workshop frequency reference and so >>>> would >>>>> like to set it close to 10.0Mhz. I have various oscillator modules, >>>> signal >>>>> generators, SDR receivers, GPS receivers, a scanner, some uncalibrated >>>>> test-gear. I live in a river valley in North Devon UK so radio >>> reception >>>> is >>>>> a bit restricted but I receive digital television via a masthead >>>> amplifier >>>>> and long downlead. >>>>> >>>>> Could someone please suggest a way of going about this? >>>>> >>>>> >>>>> >>>>> Regards >>>>> >>>>> Chris Stake >>>>> >>>>> >>>>> >>>>> _______________________________________________ >>>>> 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. >> >> >> _______________________________________________ >> 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.