Replace the duplexers antenna tee with a circulator. Tune the circulator as follows: Port A to B to pass TX frequency, port B to C to pass RX frequency. Port A to Port C isolation should be in the 20dB range or better and it still protects the transmitter and helps with mixing. RF from the antenna will still go into the receiver side of the duplexer but hey, it was going to do that anyway.
This makes a 4 cavity set of 5" cans perform like a 6 cavity set on VHF. > > <---Uhhhhh...a couple of things here: > > 1) Did I miss something here? Did someone suggest connecting a > circulator to the antenna port of a duplexer? > > 2) The whole point of a circulator is to act as a "one-way" path for > RF. Placing it in the antenna path is a bit counterproductive, no? > > 3) I disagree with your comments about "strong signals that can 'get > into' the circulator. Again, that's the whole point, isn't it? > > Ken >
