Re: Microwave Oven Choke (What's it for?)

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "David Speck by way of Terry Fritz <twftesla-at-qwest-dot-net>" <dave-at-davidspeckmd-dot-org>

Greg,
I disassembled one of the old RadarRanges as well.  It did have a separate 
filament transformer, not part of the main HV transformer.

This is useful if you even want to play with a magnetron.  You can keep the 
filament running at full standard voltage, and bring up the HV with a 
Variac until you start to get microwave emission.  I have not been able to 
get a straight answer as to whether there is a specific threshold voltage 
at which the magnetron starts to oscillate.  I wanted to use one at a low 
power to bombard gas discharge tubes passed through a hole in the waveguide.

Way back in physical chemistry lab at Cornell, I used a microwave generator 
to ionize gas in a flowing gas reactor experiment.   I tracked down one of 
them a while back but the seller wanted $600 for it.  Just one of the 
projects I pland to experiment with "someday"

HTH,
Dave
G-2,1170

>http://hot-streamer-dot-com/greg/amanad.jpg
>
>The rest of the PSU is conventional in every respect.
>Big 2300vac MOT on the left, .85uF/2500wvac capacitor
>with external bleeder resistor, bloc-style HV
>rectifier--the classic half-wave voltage doubler.
>Whatever the choke is, it is involved in the HV
>circuit. The high tension leads for the magnetron pass
>thru it. Oddly enough, I don't see a filament winding
>on the MOT. Could this be a filament xfmr, or perhaps
>a ballast for a 120vac filament? Any appliance repair
>tradesmen out there? What is that thing?