Thanks much Charles, just to remind everyone that the main idea of making the boards available was to get folks a good disciplined TCXO, not to work as a development platform to discipline external OCXOs.. Also as mentioned in the FAQ, the typical performance plots I have been sending and are also in the user-manual are gathered under optimal conditions of course: a roof-top antenna, units shielded from airflow, and units running for a couple of days before testing. Please also note that I tried an OCXO with only +/-2Hz EFC range and it did not lock due to the ~10Ks resulting time-constant and the loop being way to slow to capture the OCXO.. External oscillators should have between 9Hz per Volt to 100Hz+ per Volt EFC sensitivity from what I can tell, otherwise an OPAMP circuit would be needed to bring the EFC into that range. Sorry, I cannot propose such a circuit, but such a circuit had been sent as a schematic to the time nuts some years ago by someone if I remember correctly. Bye, Said In a message dated 10/20/2014 15:55:45 Pacific Daylight Time, csteinm...@yandex.com writes:
>here is the ADEV plot from my overnight test with the DOCXO. * * * > >This was done without any loop adjustment whatsoever, same board and >software that drives the on-board TCXO. I will let the result speak >for itself, >save to say the loop, the DAC, the DAC reference, and the GPS with a proper >OCXO can achieve performance at a level approaching two orders of >magnitude better than our spec which is 1ppb for this particular product. Thanks for the ADEV plot, Said -- more pertinent for most time nuts purposes than PN. Of course, the typical performance of the LTE-Lite with the TCXO is significantly better than the spec (according to the user manual, about 5e-11 at 1 second and 1e-10 at 10 seconds, already 1 to 1.5 OOM better than spec), so the typical improvement with the OCXO wouldn't be a full two orders of magnitude. Still, very noteworthy performance that *surely* justifies time nuts in buying one of the good, cheap OCXOs flooding the surplus market to go along with their LTE-Lite. Good show. Best regards, Charles _______________________________________________ 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.