Re: New Pseudo-toroid Available

Hi John,

> Original Poster: FutureT-at-aol-dot-com 
> Hello coilers !!
> I have made up a new type of spun aluminum pseudo-toroid.  This 
> unit is simply flat at the bottom and top, with a curved edge.  Sort
> of an oblate spheroid shape.  It is made to the same high level of
> quality and surface finish as my other true toroids.  It is formed
> from two half- shells, expoxied together the same way as my other
> toroids.  From a side-view, it looks exactly like a normal toroid. 
> This unit is 3.5" thick by 11.5" diameter, and I am offering them for
> sale for $68 postpaid in the US.  The center mounting hole is 1/2"
> diameter.  The cost is lower because fewer steps are needed to make
> this unit.
> These units can be used for a number of applications; as a normal
> toroid, as a corona shield placed below the main toroid above the
> secondary, or as corona shields to be placed at the bottom and/or top
> of a magnifier resonator.  When used below a main larger toroid, it
> can be used to increase the total topload capacitance, and thereby
> increase the sparklength in a suitable TC set-up.  For example, when I
> placed a 3" by 10" toroid below my 4" by 13" toroid on my TC, the
> spark length increased from 51" to 58" using the same power input.
> When this "toroid" is placed below a main toroid, or on a magnifier as
> a corona shield, the fact that it is not a true toroid is not
> noticeable, if the coil form is at least 6" in diameter or so. In a
> way, it is better than a toroid because it is flat and simply rests on
> top the the coil form.  This unit therefore serves as a less expensive
> alternative to a true toroid in these applications.  This unit can be
> used in place of a normal toroid however if desired, again as a less
> expensive alternative to a true toroid shape.
> These units should also be very useful for serving as the bottom
> toroid when varying the separation between two toroids as a method of
> TC tuning. 

This is exactly the shape my polystyrene foam/foil terminals take.  
Works great, easy to build and mount on top of a coil.