The 5342A counter and the 5345A counters both predate the 10811A and were originally fitted with 10544A oscillators for the option 1 high stability timebase
Once the 10811A was released the instruments were fitted with the 10811A as a production change going forward and service replacements were done using 10811A's So in this case there is no need to overthink the oscillator choice for upgrading a 5342A counter. If the 10811A is an edge connector version it will fit and provide better performance than standard TCXO Content by Scott Typos by Siri > On Dec 2, 2014, at 4:53 AM, "Dr. David Kirkby (Kirkby Microwave Ltd)" > <drkir...@kirkbymicrowave.co.uk> wrote: > > On 2 Dec 2014 03:10, "wb6dgn_...@att.net[hp_agilent_equipment]" < > hp_agilent_equipm...@yahoogroups.com> wrote: >> >> Isn't the 10811 a "double oven" oscillator (an oven within an oven)? I > also believe it has anticipator circuitry to predict changes based on > environmental parameters. Or...am I confusing this with another oscillator? > > http://www.leapsecond.com/museum/10811a/10811a.pdf > > Has a data sheet. I believe that there are variants of the 10811A that are > double oven, but not all are. > > The fan is not blowing directly onto the oscillator, as they are on > opposite sides of the case. But they are both at the rear and given the > instrument is only half the width of a 19" rack, maybe it is too close. > > I have not checked this myself, but someone said that the 5342A pre-dates > the 10811A, so if purchased a 5342A new with the high stability > oscillator, one would get another oscillator with a poorer specification. > > The 5342A/10811A combination is one of those things one would have to > test, rather than guess. It would need some careful thought about how to do > a worthwhile experiment. > > Anyway, as far as I am concerned, it is certainly worth while fitting the > 10811A, as even without any equipment other than my eyes, I can see the > last few digits are not constantly changing every second or so. There's a > dramatic improvement in short term stability. I would guess it has 2-3 > orders of magnitude better short term stability, based just at looking at > the display. Actual measurements would quantify the improvement. > > If I can get 100-1000x better performance, for an upgrade that costs less > than 25% of the instrument, that is worthwhile to me. Waiting 6 or so > minutes to get a dramatic improvement in performance is not a big deal. > Keeping it plugged in 24/7, for a bit more performance, is not worthwhile > to me, but others may feel otherwise. > > Dave. > _______________________________________________ > 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.