Bob, All good advice, however I would like to add that there are a number of duplexers out there that do both pass and reject such as TX/RX and Wacom (both the same company now I believe) and there are some other ones as well. I like the TX/RX vari-notch design where all cans in the duplexer have Pass/Reject capabilities.
Another way to deal with this is to use seperate antennas at different heights on the tower. Vertical seperation gives an amazing amount of isolation. Right now we are running VHF and UHF on a combiner/multicoupler with 4 antennas involved, and of course we are sharing that with several other systems as well. For 1296 there is a single antenna and soon we will see the arrival of our Triplexer from TX/RX that is a cross between a duplexer and combiner that allows both the Data & Voice modules for 1296 to operate on one antenna. Dan Thompson d...@waycom.com >Also use Double shielded Coax (Like RG-214 or >RG142B/U) or hardline for all connections between >the antenna and the Repeaters (especially between >the Duplexers, any preamps and the >Repeaters). Remember 98% shield still has 2% >"Holes" where RF can get in. Cheaper cables are >even worse! Also keep in mind that the >Duplexers only notch out the Transmit frequency - >they allow many "out of band" signals in. We use >DCI bandpass filters in front of the preamps to >keep out signals that get through the Duplexers.
