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Re: microwave transformers
From: Malcolm Watts[SMTP:MALCOLM-at-directorate.wnp.ac.nz]
Sent: Thursday, October 30, 1997 8:30 PM
To: Tesla List
Subject: Re: microwave transformers
Hi Greg,
That is roughly the type of supply I am currently running
on my one permanently set up coil here at work although I am using a
demountable demonstration transformer. Currents and voltage would be
much the same. I've run into gap reliability problems with a large
topload but it works OK with a smaller one.
Malcolm
> From: ghunter-at-mail.enterprise-dot-net[SMTP:ghunter-at-mail.enterprise-dot-net]
> Sent: Thursday, October 30, 1997 1:15 PM
> To: tesla-at-pupman-dot-com
> Subject: microwave transformers
>
> Anybody had success using microwave transformers to drive a TC?
> I've got two identical units removed from 900w ovens. I tested them
> with a Fluke meter and a 1:100 probe and measured the no-load
> secondary voltage at 2250vac. It occurs to me that one of these
> would make an excellent plate supply for a vacuum tube coil. They
> even have a filament supply winding. I'm a novice coiler, but the
> next time I come across a cheap 833A triode I'm going to buy it & try
> it. Anyhow, just for grins I wired the primaries in parallel and
> the secondaries in series (cores shorted together) and got 4600vac (I
> don't know where the extra 100v came from).
>
> 4600vac doesn't seem like enough for a spark-excited coil. A massive
> cap would be required to match the low secondary impedance. Also, it
> seems like the heavy spark current would quickly eat even the most
> robust gap electrodes. Anybody know how to make a workable
> spark-gap TC with these beasts?
>
> Greg