We use many ham and commercial repeaters using the same antennas, but require the proper filtering. A mobile duplexer is not sutable for what you are trying to do here. You can get a transmit combiner Hybrid or cavity for the transmitters and use a receiver multicoupler that has a dual window one for the ham receive and one for the commercial receive or use a cavity combiner for the receiver. That was is my preferred method, more isolation but costs much more.
Mike Mullarkey K7PFJ 6886 Sage Ave Firestone, Co 80504 303-736-9693 _____ From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Merrill Sent: Sunday, February 14, 2010 6:30 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Question for the group I have a very broad band uhf antenna on a tower . I would like to run a 440 MHz machine and a 462 MHz machine off of the same antenna . Can I use a notch type mobile duplexer to combine the 2 machines to 1 ant for both TX and RX to notch the respective TX freqs after the duplexers that are on the 2 machines . Merrill KG4IDD