[Hallicrafters] SX28 power transformer

[Todd, KA1KAQ]

On 7/28/05, James Richardson <jdouglasrichardson at yahoo.com> wrote:
> Hello all-
>   I will be taking Doug's very generous offer for his
> transformer.
>   The radio (probably a late run, wartime??, SX28) has
> been in damp location basement storage for some time,
> not my basement, and was brought back to life in
> stages. It was receiving CW on 80 at 65 volts. Maybe I
> should have let it cook at low voltage for a few days.
>   Or maybe the transformer was just ready to pack up.

Most folks don't give it a thought, but transformers will suck up
moisture like a sponge if left unused for an extended period of time -
especially in a damp environment. It's one of those things that folks
do who look around for modulation transformers etc: always bake the
iron for a while before using. Several hours, not just a few minutes.
175 degrees or so should do the trick.

If the radio has lead a sheltered life inside the average home, been
used from time to time and so on, it's not likely to be a problem.
Anything beyond that is a roll of the dice to just plug - n - play,
though. It's generally not practical to set the entire rig in the oven
with its plastic dials, escutcheons, and whatever else. It's
<generally> not a big job to remove the iron and bake it for a while,
and well worth the effort.

Once you get the new power transformer installed and working, pay
special attention to the audio section before you go much further.
While not especially prone to failure, the output transformers have
been known to let go in these things due to bad components failing or
just being too far out of spec. Check your voltages, change the
necessary components, and enjoy some of the best 'factory' audio from
any receiver.

Good luck - 

de Todd/'Boomer'  KA1KAQ