Re: Modular Secondary

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

Original poster: "Jan Florian Wagner by way of Terry Fritz <twftesla-at-uswest-dot-net>" <jwagner-at-cc.hut.fi>

Hi,

> The High-Tech coils use Vacuum tubes! ARRRRGGGGHHHHH

Or switch mode power supply topologies. But what's wrong with vacuum tubes
dedicated for power RF (some 100kHz) applications? Very suitable IMHO? And
not even slightly archaic. :o)

> One of my more recent ideas has been the construction of a modular 
> secondary. We can add or remove primary taps, why not do the same thing to a 
> secondary.

There was an research article on TCs, with exactly such a collapsable
coil shortly described (and also a mini 3MHz base fed coil). If you are
interested I can mail it to you.


Reminds me, an old idea I had but still have not tested: how about an
adjustable short on the top section of the secondary?

I.e.: at the top the coil former has a slot of say 20% coil length, and
some millimetres width. Inside the slot, a moveable metal rod that is in
good contact with the secondary wires (varnish sanded off along the slot,
i.e. sanded off from the inside of the secondary, through the slot).

Then, on the inside of the secondary and over the slot, glue or
melt-bond PVC or other plastic. The slot is then filled with oil or
similar stuff to prevent inside racing.

On top of the secondary there has to be a small metal dish, a bit larger
in diameter than the secondary former. Dish is connected to the adjustable
short.

The main topload will then be a large doughnut that can be slid up and
down the secondary (secondary goes through center of doughnut), and it
will always be at the same level as the secondary tapping inside the slot.
This main topload is also connected to that tapping / adjustable short.

Very much like one of those landscape view towers with an rotating ufo
where the people sit in... 8-)

IMHO this could look very neat?

cheers,
Jan

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 high voltage at http://www.hut.fi/~jwagner/tesla