"Michael A. Terrell" wrote in message
...

"DoN. Nichols" wrote:

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.

The OP will waste a lot of time and gasoline finding and testing cores
that don't work well enough.

Do you have the test equipment to measure the frequency response and
distortion of a homebrew transformer at high power levels? You need a
clean sine-wave signal generator and an amp that's better than the one
you are trying to build.

I used a home-made Super Tiger modified into a wideband op amp.
http://www.swtpc.com/mholley/Catalog1969a/Page04.jpg

It was useful as an RF transmitter at Fort Monmouth when the Signal
Corps students started competing to build and run pirate radio
stations and jammers. Electronic surplus was cheap and plentiful in
northern NJ and NYC's Canal Street in 1970 and we learned a lot
through the pranks we concocted.
jsw