You might try bringing a fluorescent light with you and seeing if it lights up. I haven't tried it with a broadcast tower, but a college physics class demo has

You might try bringing a fluorescent light with you and seeing if it lights up. I haven't tried it with a broadcast tower, but a college physics class demo has stuck with me. Here's a proof of concept video: https://www.youtube.com/watch?v=FSYj2lEaxhY https://www.youtube.com/watch?v=FSYj2lEaxhY And another with a compact fluorescent: https://www.youtube.com/watch?v=lKatgq9sjj8 https://www.youtube.com/watch?v=lKatgq9sjj8 Presuming the tower is surrounded by a chain link fence, you may need to find a way to get the bulb high enough so that it has line of site to the transmitter.