The Telewave TPRD-0354 allows the simultaneous operation of a transmitter and receiver into a common antenna. This duplexer features minimum insertion loss and maximum isolation between transmitter and receiver. The pass-reject design combines a bandpass response with a tunable notch at the receiver frequency for improved performance at close spacing. The superior construction of Telewave cavity duplexers allows better rejection of transmitter spurious radiation, providing greater receiver protection. Selectivity and insertion loss are fully adjustable by rotating the calibrated connector loops. Telewave cavities are manufactured with 1/4 in aluminum top plates which are fully welded to the aluminum outer conductor. Silver plated tuners, beryllium copper finger stock contactors, and threaded Invar tuning rods assure maximum temperature stability, higher "Q," and years of trouble-free operation.