Just did a simple test and it worked.
I placed 4 Transmitter towers and 4 Receiver towers .... i.e. a standard CH Radar setup at Dungeness. I assigned them to RED. I placed 4 HEIII out in the channel at 2000, flying directly towards the CH units. These were well outside visual range. No other AI aircraft in the Mission.
I placed myself in Spit IA over Dungeness. About 40 seconds into the mission I received a Voice and Text message with Target details that were correct.
I couldn't get any of the Vector or other commands to work though.
I am not sure if its modelled but CH units were Directional and not Omni directional like CH LOW units or those with Rotating antennas. Perhaps some of the Radar issues are directional ones ?
Single mission file attached.