[time-nuts] Re: 5061A HV Supply, et al. {External}

[paul swed]

Jim
I don't think you did. The oven turning on and off would be expected. What
happens with some luck is you will notice that the on period slowly
increases. Use a watch and check every couple of hours.
Each time it turns on the ion pump current should increase and then the
system shuts off if over about 20 on the meter.
Its a good sign if the system actually stays on.
With the missing modules the system may or may not lock. Just depends on
what ones.
Great to see your progress.
Regards
Paul

On Wed, Nov 30, 2022 at 3:42 PM Jim Muehlberg via time-nuts <
time-nuts at lists.febo.com> wrote:

> OK, after an 11 day hiatus, there is no change in ion pump current.
> Still very low (1 uA?) in "CS OFF". Switching to another mode (any)
> causes the pump current to increase and the A18 output to fold over,
> then it recovers and keeps doing this at about a 5 second period.  The
> monitor point reaches about 1.2 V before folding back.
>
> So, I found a little laser HV supply that puts out 1250V at 4mA.  So, I
> thought I'd attach that.  On my homemade 172 MOhm Divider, the voltage
> turned out to be much higher, around 7kV!  Which I only found out after
> connecting to the tube.  Hopefully, that didn't kill it.  It drew about
> 50 uA at this voltage.  I ended up leaving for a few minutes before I
> realized what was going on, since I couldn't believe the reading from my
> divider.
>
> In any event, after reconnecting the A18, ion pump current is very low
> again, but this time the monitor point stays up at around 4V with the
> clock in "LOOP OPEN".  It no longer folds back at all.
>
> Recall it has no divider module so I'm not sure monitor points are
> useful, but most are dead, except Supply, Ion Pump I, Osc Oven, CS
> oven.  There is a tiny bit of Beam current.
>
> Next steps?  Did I kill it?  I may have access to a divider module...
>
> Jim
>
> On 2022-11-09 11:07 AM, Jim Muehlberg via time-nuts wrote:
> > I've recently come into possession of a 5061A.  It is claimed that the
> > tube is exhausted, but I'm unwilling to scrap it (horrors!) yet. I'm
> > not well equipped for HV measurements, but it appears the +3500 V
> > supply is not working.  So, I'm hoping the tube just needs to be
> > pumped since it hasn't been powered for years.  Also missing the A3
> > assembly, but I'll worry about that later...
> >
> > Anyone willing to part with their A18 or loan it to me?
> >
> > Thanks!
> >
> --
> Jim
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