[SBE] Question about a toroid core --

[Mike Langner]

Hello !

I'm in the midst of repairing a 150 watts Silicon Valley Power Amplifier, a
filter-tuned unit that operates in the FM band.

It has a "toasted" toroid.  The toroid is one inch in diameter, has (or more
correctly, had before it was badly overheated) orange paint along one side,
and is used as a bifilar-wound choke wired so that it looks to the two FET's
like windings of a push-pull autoformer.

If I remove a good toroidial unit from another amplifier, the amp with the
"toasted" toroid works perfectly.

Question:

What's the toroid's makeup ?  I'm thinking as I dig into some more research,
that it's likely "43" material, but that's just a slightly educated guess.

The amplifier's manual's documentation provides no information about the
coils -- either the air-wound or the toroidial ones.

May I please ask for suggestions for the toroid's core composition?

Thanks !

Mike/

Mike Langner, CPBE
Albuquerque, NM
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