Ah. Got it finally! Doh. Just finished trying out the Morion this afternoon. Electrically works very well. Used a 7812 to drop the +15 volts from the option 1 ocxo, there is enough power headroom to bring the Morion up from cold and run it comfortably. As you said, the control voltage for the original is indeed 5 v, and can be set by the internal d/a. The output of the oscillator passes through an emitter follower voltage adjuster and through a low-q filter to three stages of ECL buffer and then out to the 10 MHz system bus clock. Another path proceeds to a relay-switched divide by 2 to the phase detector so an external 5/10 MHz source can lock the internal oscillator. The external 5/10 MHz source proceeds to the phase detector thru an identical buffer chain without the switched divider. The remainder of the clock circuits is a multiplier to 90 MHz.
I'll run the autocal tomorrow and then get some jitter stats if possible. This is an early specimen, s/n about 700 or so. I can imagine seldom used, and sitting on standby for 20 years or so, pushing the ocxo out of tolerance. The saga continues; I may have to look for a 10 MHz replacement on epay, there isn't room to put in an Hp, unfortunately. Don Bob Camp > Hi > > At least the Morion’s I have seen have 5 MHz crystals in them rather than 10 > MHz. They have a 10 MHz output due to an internal doubler. Since the circuit > is not perfect, there is cycle to cycle variation in the 10 MHz. It’s way more > jitter (measured in picoseconds) than the oscillator has due to phase noise. > My concern is that a counter might be bothered by this is some subtle way. > > Bob > >> On Nov 22, 2014, at 3:55 PM, Don Latham <d...@montana.com> wrote: >> >> Hi Bob: no. cobble, not double :-) A little research has me thinking I can >> easily adapt a morion. I can try it at least by starting with the morion on >> an >> external power supply and patching the output and control voltages in to the >> sr. >> >> The sr620 has a control circuit which apparently accomplishes your >> suggestions; they claim to use the internal oscillator for short term and >> "lock" it to a supplied external source for longer term. Probably has a long >> time constant on the built-in phase lock to do this. >> >> Anyhow, autocal calibrates everything except, guess what, the 10 mhz source. >> Thats done separately. >> So a bootup self check shows OK even if the frequency standard is way off. >> >> Onward and upward. >> Don >> >> Bob Camp >>> Hi >>> >>> I believe that the SR620 uses a “true” 10 MHz OCXO. I would be careful >>> using a >>> 5 MHz doubled to 10 OCXO. The counter may or may not be happy with >>> sub-harmonic induced jitter. >>> >>> Best bet at the specs: >>> >>> +12V power >>> 0-5V EFC >>> Sine wave out +7dbm >>> >>> +/- 5x10^-9 0 to 70C >>> >>> Pinout - trace what you have. >>> >>> Bob >>> >>>> On Nov 21, 2014, at 6:59 PM, Don Latham <d...@montana.com> wrote: >>>> >>>> >>>> So, I got a reasonable deal on a SR620 ho ho. Know your dealer. The ocxo >>>> is >>>> out of tolerance. All self tests pass with flying colors, autocal works as >>>> well. So the best parts are OK. >>>> Does anyone: >>>> 1) have a spare Isotemp OCXO36-53 10.000 MHz p/n 6-00051? >>>> 2) know the specs, ie the input voltage/current and the control voltage >>>> span >>>> and direction? pinout? >>>> I have some Morion mv-89's and could easily cobble one in if it will >>>> work. >>>> Apparently a correct oscillator must be in place to use an external >>>> source, >>>> if >>>> I read the manual right. >>>> >>>> 3) do we have a source for the schematics for the SR 620? >>>> >>>> The FTS 4060 is up, pumpin' and firmly locked. At least for now. That >>>> dealer >>>> was not lyin' >>>> >>>> Much thanks to all of you. >>>> The adventure continues >>>> >>>> >>>> -- >>>> "The power of accurate observation is commonly called cynicism by those >>>> who >>>> have not got it." >>>> -George Bernard Shaw >>>> >>>> Dr. Don Latham AJ7LL >>>> Six Mile Systems LLC >>>> 17850 Six Mile Road >>>> Huson, MT, 59846 >>>> mail: POBox 404 >>>> Frenchtown MT 59834-0404 >>>> VOX 406-626-4304 >>>> Skype: buffler2 >>>> www.lightningforensics.com >>>> www.sixmilesystems.com >>>> >>>> >>>> _______________________________________________ >>>> 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. >>> >>> >> >> >> -- >> "The power of accurate observation is commonly called cynicism by those who >> have not got it." >> -George Bernard Shaw >> >> Dr. Don Latham AJ7LL >> Six Mile Systems LLC >> 17850 Six Mile Road >> Huson, MT, 59846 >> mail: POBox 404 >> Frenchtown MT 59834-0404 >> VOX 406-626-4304 >> Skype: buffler2 >> www.lightningforensics.com >> www.sixmilesystems.com >> >> >> _______________________________________________ >> 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. > > -- "The power of accurate observation is commonly called cynicism by those who have not got it." -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com _______________________________________________ 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.