[time-nuts] Thunderbolt MV-89a OCXO Transplant?

Bob Camp lists at rtty.us
Tue May 28 21:10:09 UTC 2013


Hi

The MV89A's that are out on eBay are all custom built parts. The part
numbers on them do not fully show what they are. About the only way to find
out would be a flight to St. Petersburg (not the one in Florida) and a sneak
look at their files. If the same guy is still in charge of security that was
in charge on my last visit there ... not a good idea.

Simple answer - it's a bit of a guess as to what you have once you get past
the generic stuff. When a big OEM says "build it to this spec" that's what
everybody does.

Bob

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Götz Romahn
Sent: Tuesday, May 28, 2013 1:12 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt MV-89a OCXO Transplant?

Bob, how can I find out what the differences among various MV89 are ?
thanks Goetz

Am 28.05.2013 18:52, :
> Hi
>
> The MV89A is a 5 MHz resonator doubled to 10 MHz, it will have sub
harmonics
> that the original OCXO (using a 10 MHz resonator) does not have.
>
> The MV89A has 10 to 20 db worse phase noise as a stand alone OCXO than the
> original OCXO. That is masked to some degree by the TBolt's internal
noise.
>
> Depending on which MV89A you get (there are many flavors), it's
temperature
> stability will be 3X to 10X better than the modern versions of the TBolt
> OCXO.
>
> The ADEV on the MV89A should be ~2X better than the modern TBolt OCXO.
>
> The tuning voltage range of the original TBolt OCXO is +/- 5V on the MV89
> it's 0 to 5V. The pull range on the original is about 5X greater. Both can
> be fiddled on the TBolt via LH.
>
> Check your TBolt board for the connection (if any) to the Vref pin on the
> MV89. Shorting it to ground may not be a good thing. Of course your MV89
may
> or may not have a voltage on the Vref pin.
>
> Bob
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Frederick Bray
> Sent: Tuesday, May 28, 2013 10:37 AM
> To: time-nuts at febo.com
> Subject: [time-nuts] Thunderbolt MV-89a OCXO Transplant?
>
> Looking at the archive, I noticed that several months ago someone
> commented that the Morion MV 89A was a direct replacement for the OCXO
> in the Trimble Thunderbolt in the sense that the Thunderbolt PC board is
> configured to accommodate it.  However, I wasn't able to find further
> details.
>
> I have a spare Thunderbolt and a spare MV89A and I am considering doing
> the transplant.  Before I tear the Thunderbolt apart, I have a few
> questions:
>
> 1.  Has anyone actually performed the transplant?  (Does it work?)
>
> 2.  Are there any significant drawbacks and advantages to the transplant?
>
> I am aware that the MV 89A may pull more current on the 12 volt line
> than the Trimble and that the original Thunderbolt cover will no longer
fit.
>
> Thanks.
>
> Fred Bray
>
> _______________________________________________
> 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
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
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.





More information about the Time-nuts_lists.febo.com mailing list