[Johnson] BA transformer replacements

Mon, 04 Feb 2002 21:27:58 -0500

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
> >
> >
> >
> >
> >
> > _______________________________________________
> > Johnson mailing list
> > [email protected]
> > http://mailman.qth.net/mailman/listinfo/johnson
> >
>
> _______________________________________________
> Johnson mailing list
> [email protected]
> http://mailman.qth.net/mailman/listinfo/johnson