[time-nuts] ocxo

Don Latham djl at montana.com
Mon Nov 24 01:35:26 UTC 2014


Schematics in KO4BB magnificent storehouse.

Neil Schroeder
> Did we answer the q? about schematics?
>
> All of SRS's products have their block diagram and parts list with a
> detailed circuit description in their user manual.  Sneak preview: its all
> resistors.
>
> NS
>
> On Sun, Nov 23, 2014 at 4:22 PM, Don Latham <djl at 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 <djl at 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 <djl at 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 <djl at 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 <djl at 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 at 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 at febo.com
>> >>>>>>> To unsubscribe, go to
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>> >>>>>>> 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 at febo.com
>> >>>>>> To unsubscribe, go to
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>> >>>>>> and follow the instructions there.
>> >>>>>
>> >>>>> _______________________________________________
>> >>>>> time-nuts mailing list -- time-nuts at 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 at 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 at febo.com
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>> >>> 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 at 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 at febo.com
>> > To unsubscribe, go to
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>> > 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 at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
> _______________________________________________
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> 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





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