Properties:

An item having either a single tapped winding (autotransformer type), or two or more windings designed to furnish inductive reactance and/or transfer electrical energy in circuits by means of a magnetic field. It is so designed that its entire intended range of operations is above 20 kilohertz (kilocycles). The minimum value may extend into the audio frequency range (below 20 kilohertz). It may include integral capacitors, coils, resistors, and adjustable tuning cores. For items having only two active terminals see coil, radio frequency. Includes types having windings which may be moved with respect to each other. Excludes transformer, discriminator.