Is the ProgRock GPS disciplined or a Rb, or is it just a free-running crystal oscillator? And does LH say that the Trimble is locked OK?
Unless the PrgRock is GPS disciplined (or is a Rb), it's a pretty safe bet that it has simply grown old and the crystal has aged. And this notion is much strengthened if LH gives a positive indication that your Trimble is locked OK. Dana On Tue, May 5, 2020 at 7:17 PM Giuseppe Marullo <[email protected]> wrote: > Hi, > > I have a ProgRock oscillator that generates 10MHz and 125MHz signals. > Checking with my Trimble the ProgRock 10MHz signal is consistently below > 2.5Hz compared to the Trimble and also the 125MHz is below about 24Hz. > > My setup: > > - Simmetricon time antenna (26dB gain) in clear view > - about 10m of RG8X cable > - Trimble GPS (chinese reboxed) > - Racal Dana 1998 frequency counter with Trimble as time base > > DUT > - Progrock (https://www.qrp-labs.com/progrock.html) with > - ovenized oscillator (https://www.qrp-labs.com/ocxokit.html) > - GPSQ board (https://www.qrp-labs.com/qlg1.html) outside on the > balcony, first floor facing south (almost clear view except North of > course). connection is made using rs232 cable (about 6m) > > I tested for harmonics on my FT857D and Argo, every odd harmonic the > error increase. The radio has high stability but it is not exact for > sure. I could test harmonics with my SA but Trimble would be my only > reference. > > The question is: how could I be 100% sure that the Trimble frequency is > absolutely trustworthy? I have LH and it says oscillator is within > 300-1000ppt. > Is it enough to conclude the frequency is okay and the ProgRock is wrong? > > TIA > > Giuseppe Marullo > IW2JWW - JN45RQ > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
