[time-nuts] R&S XSRM Rubidium

paul swed paulswedb at gmail.com
Tue Jan 11 18:57:12 UTC 2011

Crazier question could it be baked in an oven or must you be able to
carefully visually watch it?

On Tue, Jan 11, 2011 at 1:53 PM, paul swed <paulswedb at gmail.com> wrote:

> Magnus
> Crazy question. Though the small rb references are difficult to disassemble
> they can be. I believe I have seen what you describe. Might this technique
> be used on those also. I have a flaky end of life old telco reference that I
> would open up to try it on. Though no heat gun.
> Does the RB really become exhausted or does it plate to the glass like you
> describe?
> Thanks for the thread.
> Regards
> Paul
> On Tue, Jan 11, 2011 at 1:26 PM, Magnus Danielson <
> magnus at rubidium.dyndns.org> wrote:
>> Chris,
>> On 11/01/11 06:43, Chris Erickson wrote:
>>> Would someone mind posting the manual for this? I have a dead one in the
>>> closet that needs my attention and I'm not quite sure where to start. The
>>> power supply works, but no other signs of life.
>> When I get around to scan it I will put it on my web.
>> I'd guess that you have the same problem as mine.
>> 1) Bring it out of the closet
>> 2) Release the lamp-removal tool (its located to the left side just behind
>> the front of the XSRM module, there is a pair of holes lower down for screws
>> holding the removal tool, but loosing one of them and you can bring the tool
>> up)
>> 3) then bring into the backside of the XSRM module and unscrew the lamp
>> anti-clockwise
>> 4) Look into the lamp. If you see the Rubidium splittered around in the
>> bottom, possibly have a dark shade on the glas... then you might consider
>> the next steps...
>> 5) Put the lamp and lamp holder upside down in some form of clamp
>> 6) Heat the lamp using a normal heat gun, heat it up properly. If you have
>> a dark colouration it will release itself as the rubidium evaporates. Keep
>> warming for a few seconds more and then let it cool down.
>> 7) When it has cooled down, look into the lamp and if you still have a lot
>> of splittered rubidium in the bottom, redo the process. It took me two times
>> to get the hagn of it... one way in the wrong orientation. When you are done
>> the rubidium should be located as a single droplet in the middle all the way
>> back in the lamp assembly.
>> 8) Reinsert the rubidium lamp, screw it in clockwise.
>> 9) Power the XSRM up and let it zimmer for 30 min or so... let the
>> amplitude rise (turn the monitor knob to "CHECK"). If it does not go up
>> there, let me know.
>> 10) Using a screw-driver slowly turn the trimmer of the OCXO assembly (Y4)
>> and see how the Control Voltage reacts slowly as a response. Then you know
>> that the loop has closed. Then in small steps bring the control voltage into
>> the middle of the response.
>> 11) Let it sit there and stabilize before fine-tuning the C-field on the
>> multi-turn knob on the front.
>> I'll scan the manual eventually, but the above is essentially what I did
>> to revitilize mine with that same fault description. If you need any part of
>> it let me know. I'll try to help you getting it up and running again.
>> Cheers,
>> Magnus
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