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

[Andy Talbot]

A simple flyback SMPSU with a Cockcroft-Walton tied on the end will give
you a simple high voltage supply.  A chain of high value resistors and you
can even stabilise it.

Andy
www.g4jnt.com



On Mon, 14 Nov 2022 at 20:00, Jim Muehlberg via time-nuts <
time-nuts at lists.febo.com> wrote:

> Rodger,
>
> Thanks for the encouragement!  I'm trying not to spend too much effort
> on this - sort of a distraction from real work.  One would think that
> NRAO would have a HV power supply lying around somewhere, but astronomy
> has gone solid state now for decades!  We have a grad student trying to
> nurse along another 5061 and we'd like to have a pair. I guess I'll
> slice open the A18 module and see what makes it tick.
>
> Thanks again,
>
> Jim
>
> On 11/10/2022 9:11 AM, Rodger via time-nuts wrote:
> > Hey Jim,
> >
> > I got a 5061a a couple years ago with high ION pump current.  In my case
> the 3500 volts was there but the tube was not pumping down, even after
> being on for weeks.  I found a Terranova 741 Ion pump power supply on eBay
> for under $100.  It was listed as not working but worked AOK when I got
> it.  It's a nice supply with variable output voltage, current limiting,
> safety interlocks, etc.  I hooked it up to the tube and let it run for a
> few weeks.  Tube pumped down successfully and is working AOK now.  My guess
> is that my A18 wasn't capable of supplying the current needed to pump down
> the tube but the external power supply was.
> >
> > Note: I proceeded very carefully with the external supply, letting it
> run for days at lower voltages and gradually working up to 3500.  Also, I
> kept the current limit set as low as it would go.  Anyway, it worked for
> me.  Good luck with yours.
> >
> > Rodger
> >
> > -----Original Message-----
> > From: Jim Muehlberg via time-nuts <time-nuts at lists.febo.com>
> > Sent: Wednesday, November 9, 2022 11:07 AM
> > To: time-nuts at lists.febo.com
> > Cc: Jim Muehlberg <jmuehlbe at nrao.edu>
> > Subject: [time-nuts] 5061A HV Supply, et al.
> >
> > 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 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
> F 434.296.0324
> www.cv.nrao.edu/~jmuehlbe
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