The Telewave Model TPRD-4556 Pass-Reject Duplexer 400-512 MHz, allows simultaneous operation of a transmitter and receiver into a common antenna. These pass-reject duplexers are ideal for systems with very close frequency spacing of 1MHz or more. The TPRD-4556 has three ¾-wave pass-reject cavities in the transmitter and receiver sections for additional isolation. Because of their superior construction, these Telewave 5” cavity duplexers achieve greater rejection of transmitter spurious and noise radiation, providing excellent receiver protection. Telewave duplexers have ¼” aluminum top plates which are fully welded to the aluminum outer conductor. Silver-plated tuners, beryllium copper finger stock contactors and threaded Invar rods assure maximum temperature stability, higher “Q”, and many years of trouble free operation.
Selectivity and insertion loss may be adjusted by rotating the calibrated connector loops. (See next page for typical response curves.) All duplexers are tuned and tested with customer-specified frequencies prior to shipping. If frequency changes are required, the positive locking mechanism allows for easy field tuning by rotating the threaded Invar rod. The optional TBC-40 indoor cabinet completely encloses the duplexer, and protects it from dust, dirt and tampering. All connections are accessible from the top of the cabinet.