[Johnson] BA transformer replacements

Tue, 5 Feb 2002 09:19:24 -0800

Hi John. No i don`t have one of those knobs kicking around here. But i do
know a few people that might and i will see what i can do for you. What is
it worth to you so i can offer a price if i find one?  Rick VE7RiK
----- Original Message -----
From: "Dr. John Harden" <[email protected]>
To: <[email protected]>
Sent: Monday, February 04, 2002 6:27 PM
Subject: Re: [Johnson] BA transformer replacements


> Hi, Rick!!!
>
> You wouldn't by chance have one of the small knobs that is used in the
KWM-2A
> to change the xtal board in use? It's located right above the band
switch...
>
> Thanks for info on bucking xfmr...
>
> 73,
>
> John, W4NU
>
>
> Rick Gouge VER7RiK wrote:
>
> > Hi John. Why not use a bucking transformer. i use one in line for all of
my
> > tube gear. 20 amp filament transformer does the job. the line voltage
works
> > out to be between 108 and 110 volts.   73 Rick VE7RiK
> > ----- Original Message -----
> > From: "Dr. John Harden" <[email protected]>
> > To: <[email protected]>
> > Sent: Monday, February 04, 2002 12:20 PM
> > Subject: [Johnson] BA transformer replacements
> >
> > > Whenever I have a transformer fail I look at a new one by Stancor,
etc.
> > > If  I can't find a replacement I use Peter Dahl. They are expensive
but
> > > extremely dependable. Old transformers usually break down and I avoid
> > > them.
> > >
> > > When the first Collins 516F-2 power supplies came out the primary was
> > > only 108 VAC!!!! The primary voltage went up over the years as Collins
> > > was aware of the increase in AC line voltages to 120 VAC or more.
> > >
> > > I recently restored a 516F-2 supply for use with my KWM-2A
transceiver.
> > > I use high-quality solid state replacements for the 5U4 and 5R4 that I
> > > purchased locally at Ack Radio Supply. Naturally I use a variac
> > > auto-transformer to set the AC. With only
> > > 103 VAC on the primary I get the rated 285 VDC and the 800 VDC out of
> > > the supply key up.....Imagine where it would be with 120 VAC or more
on
> > > the primary!!!! Old transformers will quickly break down if the input
AC
> > > is too high...
> > >
> > > 73,
> > >
> > > John, W4NU
> > > Atlanta
> > >
> > >
> > >
> > >
> > >
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> > >
> >
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