[time-nuts] Re: Attempting to start HP5061A {External}

Fri Feb 10 21:33:27 UTC 2023

Yes, it stayed green,

It didn't seem to loose time last night, but I did notice the clock will
gain a second or two when you switch between CS OFF and Loop Open

I'm going to do another tune up now that it's a bit more stable and I have
a signal generator to do the Zeeman alignment.

On Fri, Feb 10, 2023 at 6:07 AM paul swed <paulswedb at gmail.com> wrote:

> Matt that would indeed be odd that the clocks off by that huge amount.
> If you manually adjusted the 5061 by the manual, its possibly set it to
> the wrong peak. There are 3 peaks. The center is the highest.
> But even if you were on one of the side peaks its not a 40 minutes offset.
> So maybe a glitch. Especially if everythings been off a long time.
> Lock light still green?
> Regards
> Paul
>
> On Thu, Feb 9, 2023 at 11:34 PM Matt Krick <dcflux at gmail.com> wrote:
>
>> The Beam I current rose up to 45 and the front panel clock was 40 minutes
>> slow since last night but I'm going to reset it and keep an eye on it,
>> might of just been a glitch in the Matrix.
>>
>> On Thu, Feb 9, 2023 at 1:00 PM paul swed <paulswedb at gmail.com> wrote:
>>
>>> Great to hear and with a reading I see in the pix you included thats a
>>> nice tube.
>>> Appears to be 38?? Granted the beam current isn't absolute.
>>> I have a unit with 0 beam current and it still locks and is consistent
>>> with the other CS units.
>>> Regards
>>> Paul
>>> WB8TSL
>>>
>>> On Thu, Feb 9, 2023 at 1:42 AM Matt Krick via time-nuts <
>>> time-nuts at lists.febo.com> wrote:
>>>
>>>> I am pleased to report that the unit is Alive and Ticking!
>>>>
>>>> After 30 minutes of the cycling my unit stabilized. I have it another 2
>>>> hours of CS OFF mode and then started it again this time stable with no
>>>> cycling.
>>>>
>>>> With Loop Open the Beam meter started at 2 and slowly climbed to about
>>>> 15
>>>> after about 20 minutes where I did a rough tune.
>>>>
>>>> After another 20 minutes I went with Oper mode and centered the coarse
>>>> tuning getting a peak meter reading of 34. Pegging control to -50
>>>>
>>>> I then centered the control reading by again tuning coarse and hit the
>>>> reset button and got the continuous operation to light.
>>>>
>>>> I set the clock to my watch and will compare tomorrow
>>>>
>>>> On Wed, Feb 8, 2023, 15:22 Aiden Gibson via time-nuts <
>>>> time-nuts at lists.febo.com> wrote:
>>>>
>>>> > Hi Matt,
>>>> >
>>>> > Just to add another 2c to this thread, I went through roughly the same
>>>> > process Jim describes with my 5061A.
>>>> >
>>>> > I also kept the hot wire ionizer powered on in order to catch any
>>>> neutral
>>>> > particles which may have been affecting the vacuum.
>>>> >
>>>> > I took some measurements of the process to get a rough "pump curve"
>>>> which
>>>> > can be seen here:
>>>> >
>>>> >
>>>> >
>>>> https://docs.google.com/spreadsheets/d/1zsTUAiDZ92Eb-2lID9Hkoe7ByOylcx_LJ3ktGqG_uac/edit?usp=drivesdk
>>>> >
>>>> > Best of luck!
>>>> > -Aiden
>>>> >
>>>> > Sent from my Verizon, Samsung Galaxy smartphone
>>>> >
>>>> >
>>>> >
>>>> > -------- Original message --------
>>>> > From: Jim Muehlberg via time-nuts <time-nuts at lists.febo.com>
>>>> > Date: 2/8/23 17:34 (GMT-05:00)
>>>> > To: Matt Krick via time-nuts <time-nuts at lists.febo.com>
>>>> > Cc: Jim Muehlberg <jmuehlbe at nrao.edu>
>>>> > Subject: [time-nuts] Re: Attempting to start HP5061A {External}
>>>> >
>>>> > Hi Matt,
>>>> >
>>>> > I just went through this when resurrecting a 5061A option 4 that was
>>>> > about to be scrapped (Horrors!).  My ion pump power supply was flakey,
>>>> > but after I fiddled with it, I got it to work.  I then saw the same
>>>> > behaviour.  Ultimately, I connected an external supply to the ion pump
>>>> > and left it powered for a few days.  This cleaned (or whatever
>>>> happens)
>>>> > the tube and I was able to lock it.  FWIW, the supply I connected was
>>>> > about 7 kV.  The label said 3KV, but apparently that was under the
>>>> rated
>>>> > load.  In any event, I thought I wrecked the whole thing.  I was
>>>> assured
>>>> > by some time nuts that it was OK, and it was.  It's been running
>>>> > continuously now for about 2 months.  Here's an ADEV plot for fun...
>>>> >
>>>> >    Measured against another opt 4.  Both units have an unknown
>>>> history,
>>>> > and they are 40 year old tubes, so I consider this a success!  Good
>>>> > enough anyway.
>>>> >
>>>> > Good luck, and keep one hand in your pocket.
>>>> >
>>>> > Jim
>>>> >
>>>> > On 2023-02-08 12:39 AM, Matt Krick via time-nuts wrote:
>>>> > > Hello,
>>>> > >
>>>> > > I recently acquired a HP5061A and I am attempting to start it but
>>>> there
>>>> > are
>>>> > > some things that are puzzling me.
>>>> > >
>>>> > > Per the manual I have left the unit plugged in for 24 hours with
>>>> mode set
>>>> > > to CS OFF set to and I have observed the Ion Pump readings go to 0
>>>> after
>>>> > > about 3 or 4 minutes of first plugging it in.
>>>> > >
>>>> > > So now I am attempting to power up the tube by switching to Loop
>>>> open
>>>> > and I
>>>> > > can hear another power supply engage. My Ion Pump reading climbs to
>>>> about
>>>> > > 30 after about 10 seconds and then the power supply shuts off. Then
>>>> I get
>>>> > > into a cycle of about 2 seconds on for 10 seconds off with the Ion
>>>> Pump
>>>> > > going between 20-30 or thereabouts.
>>>> > >
>>>> > > I'm not sure if this is normal and part of the pumping down process.
>>>> > > Should I leave it on or keep trying to run it on CS OFF?
>>>> > >
>>>> > > Am I correct in assuming that with CS OFF the +3500V supply is
>>>> running
>>>> > and
>>>> > > that is what is acting as the Ion Pump to evacuate the tube, and
>>>> then
>>>> > when
>>>> > > I switch to Loop open that also powers  up the Cesium Heater and the
>>>> > -2500V
>>>> > > supply?
>>>> > >
>>>> > > I have experience with high power Triodes and Tetrodes where you
>>>> run the
>>>> > > filaments without high voltage to help evacuate the tube so I'm
>>>> unsure
>>>> > how
>>>> > > a tube like this operates.
>>>> > >
>>>> > > Thank you!
>>>> > > _______________________________________________
>>>> > > time-nuts mailing list --time-nuts at lists.febo.com
>>>> > > To unsubscribe send an email totime-nuts-leave at lists.febo.com
>>>> > --
>>>> >
>>>> > Jim Muehlberg
>>>> > Senior Engineer
>>>> >
>>>> > National Radio Astronomy Observatory
>>>> > ngVLA Local Oscillator Lead
>>>> >
>>>> > 1180 Boxwood Estates Rd B-111
>>>> > Charlottesville, VA 22903-4602
>>>> > P 434.296.0270
>>>> > C 434.422.2017
>>>> > _______________________________________________
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>>>> >
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>>>
>>>