Here in JeffCo, there are two dedicated analog FM frequencies designated as Helo-1 (468.00000) and Helo-2 (468.02500) that is used for Helicopter to Ground transmissions with first responders. I'm constantly hearing issues with each one hearing the other, yet I can hear both sides of the conversation. In some cases, I have heard a helo right above the LZ, and they can't hear the radio of the LZ commander, and vice-verse.
I have to wonder why the county doesn't patch the two helo channels into the local P25 system. JeffCo's system has plenty of available TG's. And the dispatchers are always patching-in systems from neighboring states, so that rules out technical speedbumps.