[TCML] microwave oven caps

[Jim Lux]

Scott Bogard wrote:
> Hey all,
>      How long can I expect microwave oven caps to last in TC service.  I 
> am planning on using 20 in series for 40 kV 50nf rating for an 
> experiment (not long runs, unless it works really well and I get carried 
> away of course, you all know how that is.)  Just curious, I don't want 
> to waste them all for a few second run.

They're mylar dielectric, typically, and pretty lossy.  Fine in DC 
filter duty, terrible for RF.  They may not last long at all if you're 
using them as your primary tank cap.

have you got a way to measure their (apparent) resistance at 100 kHz?

Then you could figure out what the power dissipation will be, and if 
they're dissipating more than, say, a watt or two, they'll probably 
overheat in short order.


> 
> Scott Bogard.
> P.S.  I am using them on a 4 MOT stack so about 8 kV RMS.  Fres is 98 
> ish kHz.
> 


Jim