[time-nuts] [Bulk] Re: New Guy, has HP 5061A with DATUM 7105A tube seeks advice

[paul swed]

Have a second to type further. If the systems been off for 6 months it will
take a long time for the ion pump to work. Simply watch the current meter
and give it 24 or 48 hours. Its very slow. Even give it a week. If the
current is coming down at all that is a positive sign. It may be quite
small and could take 2 months. Down is good.
However that in no way gives you a clue to the quality of the tube for my 2
cents.
Regards
Paul
WB8TSL

On Thu, Nov 6, 2014 at 10:46 AM, paul swed <paulswedb at gmail.com> wrote:

> actually all good advice but allow the pump to work for at least 2 weeks
>
> On Thu, Nov 6, 2014 at 8:39 AM, Scott McGrath <scmcgrath at gmail.com> wrote:
>
>> The datum tubes are fairly common as they were significantly less
>> expensive than HP/Agilent tubes and lasted longer
>>
>> First thing as JL notes is to remove battery and charger
>>
>> Just power it up and monitor the ion pump value on the test meter if it
>> drops to zero fairly rapidly the tube may still be good
>>
>> Depending on length of storage this may take up to a week to settle to
>> zero
>>
>>
>>
>> Sent from my iPhone
>>
>> > On Nov 6, 2014, at 7:54 AM, "J. L. Trantham" <jltran at att.net> wrote:
>> >
>> > I agree.  Plug it in and see what happens although I would probably
>> disconnect and remove the NiCd batteries and inspect for and clean up any
>> leakage issues.  I would also remove A2, the battery charger board, until
>> initial tests are completed.  A2 is the center board seen from the bottom.
>> >
>> > I suspect the plug you have is correct.  You probably have to
>> disassemble it, rotate the 'insert' to the proper orientation for the
>> socket on the back, 'file out' a small 'ridge' in the proper 'orientation
>> groove'  on the 'insert' that will allow the 'insert' to be reinstalled in
>> the 'housing', then reassemble the plug.  Make sure the electrical pins and
>> sockets 'line up' (A to A, B to B, and G to G) between the insert and the
>> socket on the back of the unit.  I had to do that on mine.
>> >
>> > Good luck.
>> >
>> > Joe
>> >
>> > -----Original Message-----
>> > From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of
>> Azelio Boriani
>> > Sent: Thursday, November 06, 2014 6:39 AM
>> > To: Discussion of precise time and frequency measurement
>> > Subject: [Bulk] Re: [time-nuts] New Guy, has HP 5061A with DATUM 7105A
>> tube seeks advice
>> >
>> > It is not uncommon that replacement tubes are not the original ones.
>> See here:
>> > <http://www.gigatest.net/datum/cesium_tubes.pdf>
>> > You can't do anything else than plugging it in and check the various
>> voltages. If there is any life left in the tube and the ion pump is
>> working, you can even experience a locked status in hours (tens of hours,
>> maybe).
>> >
>> >> On Thu, Nov 6, 2014 at 8:21 AM, Wayne Holder <wayne.holder at gmail.com>
>> wrote:
>> >> I recently picked up a 5061A surplus, but have no idea whether it
>> >> works or not.  The first hurdle is getting a power cord, but I'm still
>> >> waiting for the proper connector to show up (the first one I ordered
>> >> had the wrong orientation on the 3 pins.)  In the meantime, I've been
>> >> reading though what materials I can find online in order to figure out
>> >> how to  try and safely turn it on and see if the tube is OK, or dead.
>> >>
>> >> However after removing the top cover, I can see that my unit doesn't
>> >> seem to contain the typical kind of cesium tube assembly I see in the
>> >> HP docs I've found online.  Instead, it has a tube made by DATUM with
>> >> the following markings on the label:
>> >>
>> >> Model: 7105A
>> >> Serial: 9951991226
>> >> Part No: 03667-501
>> >> Oven Temp: 92 degrees C
>> >> Oven Monitor Therm: 101 Ohms
>> >> EMV: 2000 DC
>> >> NSN ______ 5960 01214 7475
>> >>
>> >> Can anyone tell me about this model and why it might have a DATUM tube
>> >> rather than the kind I see in the HP oc?  Also, any advice on how to
>> >> safely check it out?
>> >>
>> >> I bought this thing out of curiosity but, upon looking inside at all
>> >> the various dials and switches and multi-turn potentiometers, I find
>> >> I'm rather intimated by it, even though I have a fairly decent
>> >> background in electronics.
>> >>
>> >> Wayne
>> >> _______________________________________________
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