Re: AMRAD Spark Gaps

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

Original poster: "Luc by way of Terry Fritz <twftesla-at-uswest-dot-net>" <ludev-at-videotron.ca>

Hi Terry

I remember reading that they used mica gaskets in most of old quench spark gap.

Luc Benard

Tesla list wrote:

> Original poster: "Oxandale, Terry by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <Toxandale-at-SPP-dot-org>
>
> I made one of these gaps many years ago (it's in an old TCBA issue with
> a picture) back in the late '80's. With my 5" coil, I almost doubled the
> length of discharge with this device replacing the normal stationary
> spark gap. Unfortunately, they get hot very quickly, and with the
> insulators I was using between the plates (rubber impregnated cardboard
> used for gaskets in the oil circuit breakers used for distribution), I
> would have to replace them about every hour of run time due to the high
> temperature carbonizing of the gasket. My plates were simply brass discs
> (2" dia X .040") that were pressed to resemble the shape of a dinner
> plate (convex with flat edges). Then the two concave sides were place
> face-to-face together as a unit, and then these units were stacked
> together separated by the insulating gasket between each unit (about 6
> gaps total I believe). I had to devise a frame that could use a large
> fine thread bolt as a means to press all these units together tight
> enough to keep them air tight. The whole thing wasn't any larger than a
> Reubic's Cube, and was quite nice for a lower powered unit (500 to 1000
> watts) with no spark light or noise. If one was to machine the brass
> discs from large enough stock to have heat sink fins, as single piece
> units with a high temp gasket material between these units, these would
> be ideal SG for small coils.
>
> Un-Terry

Snip