Tuned RF aerial resonating with transmitter - has upper and lower telescopic sections with intermediate tubular coil in phenolic resin

摘要

A radio seria which can be tuned to resonance for the output frequency of a transmitter. Its input impedance is matched to the output impedance of a transmitter. It is automatically held in a vertical position when used indoors. The aerial consists of an upper and lower radiation section with an intermediate loading coil. There is a coupling transformer connected to the bottom end, an isolating inductance, an extendable housing, a tuning element for the loading coil and an impedance transformation element. The loading coil has the shape of a tube (20) made from phenol resin. The tube can be telescopically adjusted for the tuning. The electrically conducting element has the shape of a collar with a longitudinal slit.