Hi About the only other question would be the proper resolution for the DAC. There’s not much of a way to to answer that one without playing with a woking original OCXO.
Bob > On Nov 23, 2014, at 7:22 PM, Don Latham <d...@montana.com> wrote: > > No question about that. The morion does run a little warmer than the old unit > apparently did. Fan is temp-controlled, so I think OK. will monitor box temp > with a digital :-) thermometer, very poor resolution, but probably ok. > When I get the last obs done. will do a little blurb to the group. > Don > > Bob Camp >> 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. >> >> > > > -- > "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.