G3UUR and K8IQY have simple test circuits for measuring crystal motional parameters.
G3UUR is great for comparing or matching a batch of similar-cut AT crystals. The K8IQY method is a bit more comprehensive for "unknown" crystals and involves very tiny step sweeping around the resonance you're interested in. K8IQY detailed writeup here: https://www.k8iqy.com/testequipment/pvxo/Atlanticon2002V1R5.pdf Tim N3QE On Mon, Mar 1, 2021 at 3:36 AM Magnus Danielson <mag...@rubidium.se> wrote: > Hi, > > On 2021-03-01 01:23, Attila Kinali wrote: > > On Sun, 28 Feb 2021 18:35:57 -0500 > > Dan Kemppainen <d...@irtelemetrics.com> wrote: > > > >> If any of you have any suggestions on where to find information on how > >> to get something like this to oscillate properly, guess at correct > >> parameters, or even measure any of the parameters I would really > >> appreciate it. > > The best way would be to use a network analyzer and measure > > the crystals LCR parameters. Using that you can use the > > standard harmonic oscillator literature (Parzen, Frerking,...) > > to design the circuit. > > > > I seem to have misplaced my literature on how to measure > > crystal oscillators. But if you search for "Neubig" and > > "crystal measurement", you should be able to find some of > > the nice documents that Bernd Neubig has written on the topic. > > The same Neubig made a comment that your normal network analyzer isn't > such a good tool, even a very good one. The reason being you need both a > wide and narrow sweep to make the model values accurate enough. Most > network analyzers achieve the wide sweep, few do the narrow sweep and > then having that combined to fill in the LCR parameters of a suitable > model, not so much. Things you learn by eating breakfast with him. Turns > out that my network analyzer is good for the measurement, but not for > model fitting. > > Neubig have been very much involved in standardizing measurements, and > doing those well to characterize accurate enough those high-Q resonators > have it's challenges that leads many efforts into incorrect values. > > Cheers, > Magnus > > > _______________________________________________ > 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.