I can't help you with the technical aspects of it. Like if it will work, why it might or might not work or how to make it work. All that is simply over my head. What I can tell you is from what I can tell the majority of news copters do not use scanners in the air.
I am obsessed with police chases, I have probably watched 200-300 videos of various police chases from helicopters on the internet. Normally they do not have a scanner in the aircraft. The norm seems to be that they have someone on the ground monitoring the scanners and feeding them information via radio. Or they are in direct contact with someone at the police department. Also the pilot of the news copter will be in contact with the Police helicopter to make sure they are not in the way, or to assist in the search if need be. Police helicopters can fly faster and lower, have lights and some have infra red. What they don't have is a camera that can zoom in from over a mile away.
I know for a fact that the copter crew from LA's channel 5 uses scanners in their office. I have seen a picture of them with the female reporter sitting at them monitoring them. They have whole bank of them just like some of you guys do. When they catch something interesting they can be in the air pretty darn quick. I don't think they have one in the aircraft though. I have never heard them refer to using one. I would actually say try to contact the traffic copter people for KTLA. Mark Kono and Eliana Moreno. Mark is the pilot and reporter and Elianna is the photo journalist. They are based out of Whiteman airport. Both should be fairly east to find contact info on being they are journalists. Contact them and see if they will tell you what they use and how. The worst they can do is tell you no, but if you don't work for a competing market I wouldn't see why they would have a problem answering your question. Maybe tell them you are into scanners and car chases, not a reporter lol.