Attachment 4 VHF Duplexer Specifications.pdf

This document contains the Minimum Technical Specifications for a High Power VHF Duplexer required by the U.S. Forest Service (USFS) Land Mobile Radio program.

The duplexer must be a pass-notch RF cavity assembly capable of mounting on one side of a 19-inch rack, with one or more vertically mounted cavities. The unit shall operate within the frequency range of 138–174 MHz and support maximum power input greater than 340 Watts. The pass and reject frequencies must be separated by a minimum of 0.5 MHz or less, with insertion loss at minimum separation less than 1.6 dB and channel isolation at minimum separation equal to or better than 70 dB. The duplexer shall feature N connectors for inputs and outputs and maintain full operating characteristics across a temperature range of -40 to 80 degrees Celsius or better. These specifications establish the minimum technical requirements for equipment to be utilized in the USFS Land Mobile Radio system.