Hi, read this paper from Connor-Winfield about differences AT/SC cuts.
http://www.conwin.com/pdfs/at_or_sc_for_ocxo.pdf Am 2022-06-08 04:04, schrieb Ross P via time-nuts: > Hello,My first post.I have created a 64-bit frequency counter, 15.9 digits > after converting to floating point. > Oscillator random walk is +- 0.01 ppm with an SC cut crystal at 10 Hz > filtered, and 0.1 ppm with at cut.Is it the crystal or the oscillator > electronics (inside a can) that determines the noise?The oscillators I am > using are 1 double oven SC 10 MHz vs 1 single oven AT cut 10 MHz in one > test,and 2 generic crystal oscillators (on a Terasic DE1 cyclone II FPGA > board) for the other test.I assume the single oven oscillator will have > better stability than commodity oscillators.I am able to chart random walk at > up to a few thousand samples per second at full double precisionresolution, > and FFT shows some alien tones in the walk pattern that come and go suddenly, > I thinkdue to oscillating mode changes in the oscillator itself, mostly show > in the commodity crystals.My question is: is the SC quartz the most stable > for random walk.I would like to know if such a frequency counter / alien to > detector is useful enough to be producedfor sale? It would require at least 3 > separate frequencies of refer > ence time standards and > 50Klogic elements in the FPGA for 3 cross coupled > monitors to cover a range of 0 to 50 MHz. > Quite a risk if no one needs it. 3 separate high stability reference > oscillators are expensive.rp > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-le...@lists.febo.com _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
