Hi Kasper, Thank you, your nft program looks very interesting! It turns out the local ISP that provides my DSL, sonic.net runs a GPS-driven NTP server and I have a pretty low and stable latency, so this may work well. To measure a relative frequency offset, I presume that what limits accuracy is the total length of time of the test. So with a stable latency, I should not need to poll the server very often.
Meanwhile I have a M12+ timing GPS and antenna on order, and am assembling some glue logic, case, 3.0V power supply etc. I may not ever manage a long-term GPS installation, since my apartment is surrounded by tall obstructions, and my workplace has metallized-film window panes which block all GPS signals, and no roof access. It has a big open parking lot, though... I imagine using a car-mount GPS setup and sending a 1 Hz or 100 Hz LED or laser pulse up through the window to a telescope / photodetector at my workbench on the 2nd floor.... or maybe sending a frequency-locked 10 kHz tone through a FM wireless mic system would be adequate. -John Beale > I did a piece of software to provide calibration to equipment-deficient > microcontroller-hobbyist frequency counter builders (think 100ppm crystal > from the bin) over ntp: > http://n1.taur.dk/nft/nft.pdf > /Kasper Pedersen _______________________________________________ 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.
