Hi The whole "how to align the SR-620's" thing has been gone over in great length (and very precisely) on the list. The bottom line is that Stanford's alignment procedure is not quite as good as it should / could be.
Oddly enough, I don't remember seeing the residual offset in any brand new SR-620. I've only seen it on repaired units. My guess is that the factory tech's did a bit better alignment than the repair manual outlines. Bob On Mar 16, 2013, at 7:06 PM, Volker Esper <ail...@t-online.de> wrote: > > What "small error" are we speaking about? The statement that SRS users have > to tolerates a small error while HP users don't seems a little to general to > me. IMHO we might be a bit more precise. Anyone who's already done an error > analysis for - say - a 10MHz count and a comparison of the counters? > > In real life every type of equipment has it's domain, where it has it's > specific advantage. Could it be, that's the case for these counters, too? > > Cheers > > Volker > > > Am 16.03.2013 19:57, schrieb Rick Karlquist: >>>> 1) I paid quite a bit of money and I had it "calibrated" and fixed by >>>> SRS, >>>> and it still exhibits a significant frequency offset with a "perfect" >>>> reference and "perfect" DUT!!! >>>> >>> >>>> SRS says a small frequency error is "normal", well that prevents me from >>>> using the unit as a frequency counter, for me it's only useful as a >>>> relative >>>> display frequency counter. HP doesn't have such a frequency error, so no >>>> worries there. >>>> >> I worked with the guy who designed the HP53132A. He would >> never tolerate as "normal" a so-called small error. The term >> "frequency counter" brings to mind something that digitally counts >> zero crossings and should never have an error. First of all, even >> if that is all you do, it is still possible to screw it up. >> Secondly, "counters" have relied on analog interpolation even going >> back to the HP524 circa 1950. There is no theoretical basis of having zero >> error in this case, but the idea is that you display the number of >> digits that are commensurate with the worst case accuracy of your >> interpolator. Again, my colleague who designed the interpolator >> did very high quality work. I am pleased to learn that our stuff >> is better than the stuff from the company up the road. >> >> Rick Karlquist N6RK >> HP Santa Clara Division 1979-1998 >> (still working for Agilent!) >> >> _______________________________________________ >> 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. _______________________________________________ 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.