Hi That sounds fine. Without knowing just what they did or didn’t do, it’s always worth being a bit careful.
Bob > On Nov 23, 2014, at 6:40 PM, Don Latham <d...@montana.com> wrote: > > Running very nearly continuously for about 4 days now. The self-measured > jitter is mean 0 and sdev of 8 ps. I don't think there is a problem with the > Morion. I'm using my newly acquired cs source and a couple of z3801's for > checking. 1 bit on the SR's frequency calibration dac seems to be about 4-5 > parts in 10^-10 if I'm reading things right. Next test is a z3801 driving the > external freq port on the sr to see if the frequency change direction of the > morion is OK. > The scope display output from the SR620 is great! > Lots to learn. Also have one of Said's units coming. Gone nuts for time, won't > do anything much new, but it's new to me. All this to drive moonbounce... > Don > > > Bob Camp >> Hi >> >> If all the “good stuff” runs on the 90 MHz, the 5 MHz issue may not be >> important at all. It’s just something to watch for. If you start seeing data >> in two groups, each one 20 ps wide and separated by maybe 200 ps, you are >> seeing a problem from the 5 MHz. >> >> Running the box for a while before doing a full detailed cal is a very good >> idea. It’s a bit warm inside and some of the stuff is temperature sensitive. >> You want it to reach equilibrium. >> >> Bob >> >>> On Nov 23, 2014, at 1:06 AM, Don Latham <d...@montana.com> wrote: >>> >>> 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. >> >> _______________________________________________ >> 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.