Re: Elevating Secondaries (was Re: First Spark)

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

Original poster: "Ed Phillips" <evp-at-pacbell-dot-net> 

"Hi Ed, All,
      In keeping with your suggestion, I am looking for a low-rpm
motorized
jack screw with a large (~1") diam. non-conductive screw, nut, and base
plate. Here in the hills of WV, there is a plastics fabricator where I
can
have one made, but they want my "left one" as a down payment. :^(((
Anyone
have a line on a surplus place that might handle an item like this?

Matt D. "

	That's elegant but way overkilling the problem.  I'd just make up some
pads of wood or styrofoam or whatever's handy.  Combinations of 1/4",
1/2", and 1" would give you quite a range of adjustment.  I'd start with
the bottom of the secondary up an inch from the bottom of the primary,
tuning for maximum good and recording the results, then lowering it in
steps and repeating the tuning and recording.  At least in my experience
the coupling isn't very critical (although there does seem to be a broad
"sweet spot") but tuning is.  As you increase the coupling you'll almost
certainly find yourself increasing the turns on the primary.

	If things are still getting better with the bottoms of the primary and
secondary on the same height (easy place to start, too) then you might
jack up the primary in steps but you'll probably start having troubles
with secondary to primary arcing.

	By the way, I suspect your problem is tuning (primary too HIGH in
frequency) and not coupling.

Ed