I was reading this thread and all the concerns about oil in the capacitor. Has anyone ever thought about trying SF6 as a dielectric? It's commonly used in high voltage (hundreds of kilovolts) switchgear by utilities.
Just a thought, more curiosity than anything else. -Bill Sent from my iPhon On Jan 30, 2014, at 5:32 AM, "Tom W8JI" <[email protected]> wrote: > Still I am intrigued by the thought of a remote tuning capacitor via > hydraulic tubing :-). The capacitor plates could be as simple as two > concentric cylinder conductors with appropriate spacers. I betcha crud > collecting on the top of the oil would set voltage limit.>>> > > I would be as concerned, or more concerned, with the dissipation factor of > the oil at short wave frequencies. > > The thing that worries me is I cannot recall every seeing a single good > high-Q oil-dielectric capacitor above power line and audio frequencies. As a > matter of fact, many years ago I tried to use a surplus 20-40kV oil capacitor > from Fair Radio as a plate blocking capacitor, and it overheated so badly it > exploded. > > I looked for HF data on mineral oil as a dielectric and couldn't find > anything. That would be my main concern. I guess I could stick mineral oil > between the plates of a capacitor and see what happens to Q. > > > _________________ > Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband
