I understand your concerns, it's a $500 device that you would obviously rather not get hassled about or worse, including having it confiscated or being detained yourself. I get it. I won't go so far as to say you're making a big deal over nothing, because all it takes is one TSA agent or cop who is ignorant of the law, or has a hard on for scanners, and all of a sudden your trip to NY turns into a nightmare.
My advice was "be smart about it", which by the way includes being honest if asked what it is. Saying "Oh it's a weather receiver" is not being completely truthful, and if the TSA agent/cop knows exactly what it is, but asks as a sort of test to gauge your honesty, you're going to have a problem if you get caught in a lie. If you want to downplay it, just saying something like "Oh it's a scanner, you know to listen to the fire dept and stuff". Law enforcement generally doesn't consider monitoring the fire dept to be any kind of threat, as opposed to if you had their frequencies scanning and he was hearing himself come blaring out of the speaker whenever he keyed his mic.
NY is really not such a Gestapo police state like one (out of state) poster suggested in his little tangent. If you get asked what it is, just be cool, honest, and no one will bust your balls.