[Amps] toroid tank coil heating up

[Gary Schafer]

If the winding has taps for 80 and 40 and the taps get shorted with the band switch, then that is the problem.
You should use separate cores for each band.
If you were to leave the taps open then you may have arcing problems.


Sent from my iPhone

> On Sep 26, 2021, at 10:54 AM, John Keating <john.keating at outlook.com> wrote:
> 
> My 2 x 3-500Z amp uses a two-stack T-225A-2 red mix iron powder toroid for 160-80-40. It gets hot, especially on 160, changing the loading and causing the grid current to drift up on extended transmission. This is not a new phenomenon, but I thought I would ask the experts if there is a remedy, perhaps other than using a triple stack or going to an air core coil, neither of which I have room for.
> 
> John
> AI6LY
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