Update:
I normally get the INTERMOD during transmission of a department I monitor that is roughly a half mile from my locaton. The agency will tone out and the INTERMOD sometimes covers the tone and carries into part of the dispatch.I'm beginning to wonder if anttena design has something to do with it? I've tried just about everything else I can think of to isolate this.
Everyone needs to understand that the adjacent channel rejection and front end overload from strong signals not even close to the channel your trying to hear on most scanners is just plain very very poor. I know you paid a bundle for your scanner, but you have probably heard all this before.
My suggestion might to be to consider obtaining a used commercial radio just for the channel you want to put on a live feed broadcast. This way your getting a good receiver that has good adjacent channel rejection and a front end on the receiver that is not so effected by strong off channel signals.
Just make sure the radio is capable of narrow band operation if your going to use it on VHF or UHF public safety channels. Not all used commercial radios showing up for sale these days can be programmed for narrow band operation. Buyer beware of what your buying.