Re: Secondary Elevation

Hi Steve,

At 06:51 AM 10/14/1999 -0600, you wrote:
>Hello TC experts,
>To get the maximum performance from a TC and to eliminate damaging
>secondary "racing sparks" along its surface, the pri-sec coupling needs to
>be optimized.  This is typically done by varing the height of the bottom of
>the secondary winding in relation to the plane of the primary winding
>(assuming a flat spiral).  Some questions:
>1) Is there a rule of thumb or empirically derived equation which gives a
>good starting point for pri-sec height difference for a given sized
>secondary?  E.g., something like height difference = sec diameter/4?

No rules.  Start high and work your way down closer and closer to the
secondary till you get the best output without racing arcs.  there are ways
to calculate primary to secondary coupling but simply testing it a far easier.

>2) I would appreciate ideas you have incorporated into your coils for
>varying the pri-sec height differences.  I am interested in building a
>research coil which has this parameter adjustable in, say, quarter inch
>increments.  Ideas for either adjusting the secondary or primary height,
>while still retaining physical stability and esthetics of both, are what I

I have made a three sided wood frame with 1/4 inch holes drilled in it that
I insert wood pegs into.  See:




>Thanks in advance,
>--Steve Young
>P.s.  I suppose the best answers to these questions would be candidates for
>the FAQ compilation.