Didier wrote: > >> -----Original Message----- >> From: time-nuts-boun...@febo.com >> [mailto:time-nuts-boun...@febo.com] On Behalf Of Bruce Griffiths >> Sent: Saturday, March 07, 2009 8:48 PM >> To: Discussion of precise time and frequency measurement >> Subject: Re: [time-nuts] About HP10544A >> >> Scott Newell wrote: >> >>> At 07:41 PM 3/7/2009, Tom Van Baak wrote: >>> >>> >>> >>>> I know *late* model 5245L counters used the 10544A oscillator. >>>> Perhaps others in the group can provide other examples and >>>> >> then you >> >>>> can head off to the online manual sites and grab the info you need >>>> from the PDF files. >>>> >>>> >>> My 5345A has a 10544A. >>> >>> >>> >> Scott >> >> The 10MHz buffer is merely a cascade of 3 ECL line receivers. >> >> Bruce >> >> > > Bruce, > > How much isolation can on expect to get from that kind of buffer? > > Didier > > > Didier
The 5345A buffer is actually a CC stage feeding a CB stage with a CE (with series feedback) output stage. Total reverse isolation will probably be somewhere in the vicinity of 100dB or so. However coupling via the bias circuitry will reduce this somewhat. Cascading 3 ECL line receivers (longtailed pair plus output emitter follower buffers) in a single package as in the 5370A should achieve a reverse isolation of 60dB or so per stage, but package parasitics and coupling through the internal bias regulator etc will limit this to a somewhat lower value. Bruce _______________________________________________ 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.