[Boatanchors] 812 Self-Rectifying Power Oscillator

[Chuck McGregor]

Diathermy was wherever the patient wanted it to be,  until the evil FCC
banned it to an ISM frequency at 27 MHz (in the 1930's, I believe). My
grandfather's diathermy set had a big knob labeled "Patient Control" which
controlled the big air-variable capacitor for the push-pull oscillator tank
coil. Changing the frequency apparently changed the effective penetration
depth, affecting the patient's sensation of warmth.  Sadly, I was too young
to have seen this set in operation before it was banned.
73,
Chuck

On Fri, Jul 20, 2012 at 4:08 PM, Geoff <geoffrey at jeremy.mv.com> wrote:

> Diathermy was up around 27mc back then.
>
> I was given a 3 x 812 with 866 rectifiers induction heater made by Marion
> Instruments. Has a big fat LF coil.
>
>
> ----- Original Message -----
> From: "Mark Foltarz" <Foltarz at rocketmail.com>
> To: <boatanchors at mailman.qth.net>
> Sent: Friday, July 20, 2012 8:54 AM
> Subject: Re: [Boatanchors] 812 Self-Rectifying Power Oscillator
>
>
> Sounds like an old diathermy machine
>
>
>
>
> >________________________________
> > From: David Stinson <arc5 at ix.netcom.com>
> >To: boatanchors at mailman.qth.net
> >Sent: Friday, July 20, 2012 8:50 AM
> >Subject: [Boatanchors] 812 Self-Rectifying Power Oscillator
> >
> >I recently acquired a self-rectifying power oscillator
> >using an 812 tube. Frequency appears to be longwave
> >with a big link-coupled output. The switchable outputs
> >are marked "Tank One" and "Tank Two."
> >Electroplating?? Anyone know, and the why of
> >high-power RF to do it?
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