[Test-Equipment] SOLA CV Transformer

[Barry]

I saw that one and, truthfully, while it may work, it is in rougher condition than mine.  Regardless, I'm not going to pay that much for a replacement.

I have already substituted a 6.6V transformer and reduced the input line voltage such that it produces 6VAC and that works.  I doubt the meter really needs a CVT anymore; however, it does have some very sensitive input values (e.g. the lowest DCA scale is 15nA - yes 0.015uA!) so a stable power supply may be more critical in this meter than other VTVMs.

I expect I could get by with a simple 6V wall wart or a small 6V transformer but I would like to keep the meter as original as I can.  It was made by the Acton Corporation in the mid-1950s and I've only seen one other like it in the wild.  Coincidentally, the fellow that owns the other one is also in the process of refurbishing his and I hope his CVT doesn't have problems.

I'm still hoping I can dig the cap out of that gooey mess, replace it, and have it running again.

Thanks,
Barry - N4BUQ

----- Original Message -----
> From: "Patrick Thompson" <wa4tuk at gmail.com>
> To: "Discussion of Electronic Test Equipment" <test-equipment at mailman.qth.net>
> Sent: Friday, April 16, 2021 12:24:08 PM
> Subject: Re: [Test-Equipment] SOLA CV Transformer
> 
> I don't have any information to share but a search showed up a transformer
> at vivatubes for a whopping $250.
> 
> I'm assuming the vtvm has sentimental or historic value.
> 
> I think I would leave the CV transformer in place just for show and replace
> its function with solid state regulators.
> 
> Pat
> 
> On Thu, Apr 15, 2021, 8:55 AM Barry <n4buq at knology.net> wrote:
> 
> > I should have mentioned that the model number for the SOLA is 30488.  It
> > is designated as having 115V input and 6V output.
> >
> > Thanks,
> > Barry - N4BUQ
> >
> > ----- Original Message -----
> > > From: "Barry" <n4buq at knology.net>
> > > To: "Discussion of Electronic Test Equipment" <
> > test-equipment at mailman.qth.net>
> > > Sent: Thursday, April 15, 2021 7:17:43 AM
> > > Subject: [Test-Equipment] SOLA CV Transformer
> > >
> > > Hi folks,
> > >
> > > Anyone here familiar with older SOLA Constant Voltage transformers?  I
> > have
> > > one from a VTVM that was manufactured in the late 1950s and it is failing
> > > after warming up.  I presume that resonance capacitor is going bad -
> > perhaps
> > > exacerbated with heat.
> > >
> > > I opened the unit up and it has a significant amount of tar(?) poured
> > > in/around the transformer.  The cap is somewhat in a better position to
> > be
> > > replaced and I think I can dig enough of the goo out from around it to
> > get
> > > it out so this might not be too bad of an operation but I thought I'd ask
> > > for any advice from the group as to how I might go about this.
> > >
> > > Furthermore, if I can get it out, I'm thinking it might not be marked
> > and, if
> > > so, I don't know what value capacitor should go back in there so looking
> > for
> > > advice on that as well.
> > >
> > > Thanks,
> > > Barry - N4BUQ
> > >
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