Hi Bob -- A GPSDO can replace the OCXO in your counter, and that's now most folks would use it.
If you just want to calibrate the OCXO, you don't need a GPSDO -- you can do that with just a GPS that has a pulse-per-second output, and a scope. Use the GPS PPS to trigger the scope and adjust the OCXO for a stationary display of the OCXO waveform. It's easiest if you use a PPS derived from the OCXO (there are inexpensive dividers that will do that) but you can also do it by looking at the 10 MHz directly -- adjust until the zero-crossing point of the sine wave stays put; when you're more than 1 Hz off you'll need a bit of guesswork, but once you get within 1 Hz you'll be looking at the same cycle position each second. If it takes 10 seconds to drift one cycle on the display, you're 0.1 Hz off. John On Jan 26, 2019, 7:15 AM, at 7:15 AM, "Richard (Rick) Karlquist" <rich...@karlquist.com> wrote: > > >On 1/25/2019 10:06 PM, Bob Albert via time-nuts wrote: >accuracy of only about 1 part in 20 million. I want it somewhat >better, >but no way do I need it 100 times better. If I could set it within 0.1 > >Hz that would be fine - it would enable frequency > >You're kidding yourself on the 1 part in 20 million. >The propagation effects are such that there is >doppler shift on the frequency that you hear that >is much greater than that number. You really do >need GPS. > >Rick N6RK > >_______________________________________________ >time-nuts mailing list -- time-nuts@lists.febo.com >To unsubscribe, go to >http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.