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Greetings all, There are two AM Radio broadcast (talk radio) stations in my area. One uses three commercial towers and the other uses one, not that the number of towers matters.........or does it ? In my attempt to place a GMRS repeater on the air it has become painfully obvious that I am not able to achieve the antenna height needed to render this repeater to be of much use to most people, including myself, since the maximum range in all directions is just over 7 miles using a 25-30 watt mobile approximately 3.5 miles for handheld use. I noticed that none of the towers that the AM radio stations have, have any (that I can see) antennas mounted to them and remembered learning somewhere, that AM Radio transmitters use the tower structure as the antenna so with that in mind, it’s understandable not seeing other antennas on the tower. But, that got me thinking....... I remember years ago on the opposite side of the county the local AM (country music) radio station and the State Highway Patrol (using VHF) shared a tower and it worked quite well for both parties except for the last 5-10 years. During the end of this setup, every time the Highway Patrol dispatcher would transmit, the music from the radio station would also come across but was at very low levels sort of like “background” (no pun intended) music so you could still hear the dispatcher with no issues. I’m guessing this could have been mitigated with either filters or some form of adjustment but wasn’t since the State was in the process of switching to an 800 trunked system. So, now that I’ve written a short story........... This answer might be obvious to some but as I’m still learning, I could use some help. Can a GMRS/UHF repeater antenna be mounted on an AM radio tower without causing problems for both users? Is there additional equipment needed for either party, other than what’s already in place for the radio station and for the repeater side, the repeater with duplexer, feed line and proper grounding ? I look forward to the always helpful and friendly advice and guidance I continue to receive from the members. J