High-precision variable radio frequency coil

Claim 1

A variable inductor comprising a coil; a casting; said casting enclosing said coil; terminals connected to said coil extending through said casting; a movable core; said coil and casting have an opening in the middle of said coil which will accept said movable core; said casting forming internal threads which have a center line approximately equal to a center line of said coil; a screw means adapted to mate with the threads of said casting; said core being joined to one end of said screw for movement thereby into and out of said Coil; a silicone adhesive; said screw means having an opening in one end in which said core is attached by means of said silicone adhesive; a dummy terminal having one end bent in a hook shape and embedded into said casting, and having another end protruding out from said casting; said casting being made from epoxy resin; said screw means being made of polycarbonate plastic; said screw means having a radial hole drilled radially all the way through said screw; a silicone rubber tension rod of a length longer than the length of said radial hole; said tension rod being compressed into the radial hole in said screw means; and said screw means having a slot on the end opposite the end the core is attached to.