On 2014-01-20, Michael A. Terrell wrote:

"DoN. Nichols" wrote:

On 2014-01-19, Michael A. Terrell wrote:
" wrote:

[ ... ]

A large, powdered iron toroid works even better. Like an old 3A
variac.

Woah! A Variac did *not* use a powedered iron toroid -- nor
did the Superior Electric "Powerstats", nor any other variable
autotransformer by anyone else that I ever saw. :-)


The one I had was salvaged from a damaged, imported 3A unit.

Imported -- who knows who made it then, or what modifcations to
the design.

[ ... ]

I needed a modulation transformer for a AM mobile radio back in
the '70s. I wound a second winding on a surplus 88 mH telco toroid, and
had excessive audio bandwidth.

:-)

Filtration time. :-)


No, I liked the shocked responses I got from other users. Everyone
else sounded muddy, with their 2K roll off. That radio sounded crisp
and clear after on going through one frequency limiting core than the
usual pair.

Doesn't the FCC get upset if the modulation frequencies push the
bandwidth too far out? Or was it less critical in the '70s?

Enjoy,
DoN.

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