Hi Missing step from that YouTube video:
Stuff a fixed resistor into the 150B and calibrate the Rm per the manual. Without that, your resistance numbers can be pretty far off. In a production setting some of the Saunders gear got “calibrated” (or at least checked) each time the frequency band was changed ….. http://ftb.ko4bb.com/manuals/73.64.254.239/Saunders_and_Associates_Crystal_Impedance_Meter_150B_Service_Manual.pdf <http://ftb.ko4bb.com/manuals/73.64.254.239/Saunders_and_Associates_Crystal_Impedance_Meter_150B_Service_Manual.pdf> Section 4 ( Operation ) Paragraph A ( first step in operation) … Calibration Resistor. ( and on from there). The approach for the other Saunders stuff is similar, but the details change a bit from model to model. While they like to talk about super duper fancy standards. Check it with a 51 ohm 1/8W carbon comp and see what you get. Compare that reading to what your 3456A says ….. Fun !!! Bob > On Mar 1, 2021, at 10:38 AM, Azelio Boriani <[email protected]> wrote: > > This (see jpeg picture) crystal from Morion seems to have a Q of > 1147576, as measured on a Saunders 150B. > > Youtube video of the 150B in action: > <https://youtu.be/y-rCgumTn4Q> > > Parameters from the 150B: > Holder, Cs (pF), Ct (pF), Fs (MHz), Fp (MHz), Rm, C0 (pF),Cm (pF), > Lm (uH), Qu > Glass, 25, 31.05, 5.127993, 5.128964, 2.3, 6.05, 0.011759, > 81917.1860871, 1147576 > > On Mon, Mar 1, 2021 at 3:46 PM Bob kb8tq <[email protected]> wrote: >> >> Hi >> >>> On Mar 1, 2021, at 3:32 AM, Magnus Danielson <[email protected]> wrote: >>> >>> Hi, >>> >>> On 2021-03-01 01:23, Attila Kinali wrote: >>>> On Sun, 28 Feb 2021 18:35:57 -0500 >>>> Dan Kemppainen <[email protected]> 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 >>> >> >> A while back I got drafted into writing the code and validating the procedure >> to do this commercially. With care, it can be done and the results are quite >> good. As you would expect, there are various gotcha’s you run into. >> >> Along with the network analyzer (resolution and noise) , it depends a bit on >> the >> crystal you are looking at. High Q low frequency crystals are a challenge >> for the typical >> network analyzer. Something like a 150 MHz fundamental is generally pushing >> things like test setup (…. rigid cables are a good idea) more than the >> analyzer. >> >> Yes this assumes you are looking at “real” ( = expensive) analyzers rather >> than >> the low cost stuff. There is a reason people pay for those great big boxes >> …. :) >> >> Fun !! >> >> Bob >> >>> >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > <Morion5128kHz.jpg>_______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
