Hi If the VCXO's tuning voltage runs from zero to 5 volts, and the VCXO tunes 0.1 Hz / 0.5 volts at 12 MHz, then it has a total range of about 1 Hz at 12 MHz. That's about 0.08 ppm of tune range. A generic crystal likely has a tempo of 0.1 to 1 ppm / C. My guess is that you will need a bit more tuning range on the VCXO to keep things locked long term. Putting your tuning cap in series with the varicap should help this a bit. You may also need to add a coil in series with the crystal.
Bob On Mar 31, 2013, at 6:30 PM, paul swed <[email protected]> wrote: > Thanks John. > > > On Sun, Mar 31, 2013 at 5:21 PM, John Ackermann <[email protected]> wrote: > >> At Paul's request, I've put his document about the PSK scrubber for WWVB >> at: >> >> http://www.febo.com/pages/**wwvb_psk/WWVB%20d-psk-r%**2003302013.pdf<http://www.febo.com/pages/wwvb_psk/WWVB%20d-psk-r%2003302013.pdf> >> >> John >> ______________________________**_________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/** >> mailman/listinfo/time-nuts<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.
