[time-nuts] New Guy, has HP 5061A with DATUM 7105A tube seeks advice
paulswedb at gmail.com
Thu Nov 6 13:01:52 EST 2014
Pete thats quite a hint on the official fumes measurement scale.
Frankenstein takes a solid 24 or so hours to your one. So it seems on the
CS scale of life you are fumes and I am wisps. The meter shows just about 0
photo. Very tough to work with have to play games with meter amplifiers and
But I do get the green and the darn thing does lock on its own with
reasonable 2nd harmonic.
So there you go Wayne. Always hope.
On Thu, Nov 6, 2014 at 12:54 PM, Pete Lancashire <pete at petelancashire.com>
> If after say a week and the current does not go down, there is one more
> thing you can do before you have a tube that qualifies as a door stop. You
> replace the internal HV supply with 3,500V @ 5 mA I had to do this on mine.
> Keep doing it a few minutes at a time, took something like 3 hours.
> No drop in current until the very end and all of a sudden the current
> starting going down. I put the tube back in the 5061A and after the current
> dropped there was enough Cs left to get the thing to work. Just like Paul
> I'm sure there is very little left.
> I turn it on every 3-4 months and let it run for about an hour. The last
> few times it took a while to lock and go 'green'
> On Wed, Nov 5, 2014 at 11:21 PM, Wayne Holder <wayne.holder at gmail.com>
> > I recently picked up a 5061A surplus, but have no idea whether it works
> > 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
> > 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
> > 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
> > 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
> > intimated by it, even though I have a fairly decent background in
> > electronics.
> > Wayne
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