Re: Off-axis primary inductance

In a message dated 12/8/98 3:33:37 AM Mountain Standard Time, tesla-at-pupman-dot-com

>  	Inductance depends on the number of turns.  I have a variometer here
>  which has an inductance range from 3500 microhenries to 8000
>  microhenries.  Have made several with somewhat lower inductance.  As for
>  the insulation, the thing is just a couple of coils, so isn't any harder
>  to insulate than the TC primary or secondary.
>  Ws
    What I had in mind is a variable inductor that is adjustable from 0 to
about 10 uH.  This would allow fine tuning equivalent to about one turn of the
primary.   I decided that this would be too much trouble to build at the
moment.  I made a tuning coil by winding some 5/16 copper tubing(with 1/4 inch
spacing) around a 3 inch cardboard tube.  I measured 10 uH on the 15th turn,
so I believe this will do for me. 
    I just plan to tap this tuning coil as one would normally do with the
primary coil.  The one advantage to this is that I won't have to make
connections all around the primary to hone in on the sweet spot.  Once I get
it in tune, then I can have a good estimate of where to tap the primary and
remove the tuning coil from the circuit.