I got mine from Radio Shack and it doesn't have all the bells an whistles on it except it does scan for a working WX RADIO channel when you first turn it on. This is a RADIO SHACK model 12-260 (Less than $20 bucks as I recall)
This one is hardwired into the the trailer 12VDC using one of the DC VOLTAGE TAP adapters from radio shack. I think the operating voltage is 6VDC. Mine is on 24/7 inside the trailer when we are on the road.
Wouldn't leave home without one.. Especially for us POPUP guys... ALways nice to know when the next wind storm is coming thru...
Roy Ken