Hey everyone, Working on a MSF5000 repeater with a 457 receiver getting overload from a nearby 152 data transmitter (almost exact 3rd harmonic). The two towers are about 10 miles apart and of course line-of-sight. I seem to recall that UHF duplexers only have a useful range of 300-600 Mhz so that might explain why the 152 signal comes through so strong (monitoring on the receive port of the Moto T4084 duplexer). The 457 "harmonic" signal is also very splattery so I'm not entirely convinced its just a mathematical problem, but I'll address that later...
What would be the best course to eliminate this signal? I can't notch out the harmonic since it falls almost exactly across our receiver, so going after the 152 signal makes sense. Can I add a stub tuned 1/4 wave with a T between the duplexer and receiver? Do I need something stronger as a notch filer, or some sort of band-pass? Thanks in advance for any help. Tony
