[Johnson] BA transformer replacements

John W. Harden, Jr. [email protected]
Tue, 05 Feb 2002 19:58:21 -0500


Dear Rick,

I need one so I'm prepared to pay!!!

73,

John

Rick Gouge VER7RiK wrote:

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