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406-512 MHz Base Station Duplexer (Used)
The Telewave Models TPCD-4554 and TPCD-4556 allow simultaneous operation of a transmitter and receiver into a common antenna. These bandpass duplexers have low insertion loss, and are ideal in frequency congested areas where protection is needed from surrounding transmitters, and where maximum transmitter sideband filtering is necessary.
Because of their superior construction, these Telewave 5” cavity duplexers achieve greater rejection of transmitter spurious and noise radiation, providing excel lent receiver protection.
The TPCD-4554 has two, and the TPCD-4556 has three, ¾ -wave bandpass cavities in the transmitter and receiver sections. These duplexers are designed for transmitters and receivers with frequency spacing of 5 MHz or more. Selectivity and insertion loss may be adjusted by rotating the calibrated connector loops. (See next page for typical response curves.) Telewave duplexers have 1/4- inch aluminum top plates which are fully welded to the aluminum outer conductor. Silverplated tuners, berylium copper finger stock contactors and threaded Invar rods assure maximum temperature stability, higher “Q”, and many years of trouble free operation.
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.