Hi If you are buying them on eBay, it is not at all clear which OCXO your A or B will show up with. The 10811’s get swapped back and forth with earlier units in a lot of used gear. One might *think* it’s a one way exchange, but I’ve seen it go both ways.
If you lock the counter to an external standard, it really does not matter a lot which OCXO is in it. Bob > On Jul 20, 2019, at 4:21 AM, Frank Stellmach <frank.stellm...@freenet.de> > wrote: > > Hi Mr. Taka Kamiya, > > the B version has a 500MHz front end, copied from the HP5345A, with a matched > pair of amplifier / Schmitt trigger hybrids. > The A version has separate amplifier and Schmitt trigger ICs. > > There were also changes on the trigger circuit. > > Then the B version has a simplified µP board, has the OCXO (10811-60111), > which is a must for absolute T.I. and frequency measurements. > > Maybe the firmware was also improved a bit, I think mainly concerning the > GPIB steering of the trigger circuit. > > This T.I. counter is supposed to be superior over others of that era, because > this special time interpolator was more linear. > > I really love mine, so I don't want to sell it. > > Frank > > > _______________________________________________ > 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.
