I've seen references to the use of a 440 duplexer on the third harmonic for 1.2 GHZ use... What would be better, a plain notch type, 4 or 6 cavitiy unit, or a BP/BR type... Thinking that the notch reject would be easier especially when considering it's a 20 MHz split for 1.2 repeaters.
Dave WB2FTX