Re: Off-axis primary inductance

Tesla List wrote:
> Original Poster: Hollmike-at-aol-dot-com
> In a message dated 12/3/98 12:42:53 AM Mountain Standard Time,
> tesla-at-pupman-dot-com writes:
> > Use a variometer (goniometer) coil to tune a high current circuit.  A
> >  variometer can be made with a coil inside another coil.  one of the coils
> is
> >  gimballed so it can rotate to aid or oppose the other.  As the movable
> >  coil's axis is rotated 180 deg, the total inductance smoothly varies from
> >  max to min.
> Will,
>    This sounds like a cool idea too.  Do you have any pictures of such a
> device?
> Mike

	Look in any old "radio book".  By the way, the rotation of one of the
coils is for convenience, rather than necessity.  You can get the same
effect by simply sliding one coil in and out of the other.  Simpler by
far to build, and plenty adequate for tuning a TC primary.