These posts about Tropo and E-Skip brought up a question that I had for a while. I don't have or use HD Radio in my car, but long ago used an FM modulator to broadcast music and podcasts from my phone on empty signals (usually used 103.7 as to not interfere with adjacent signals in my area). It was strong enough to interfere with an FM analog broadcast for nearby cars, if I decided to set it to a frequency occupied by a licensed station. For example, testing it in my driveway, I once blocked out Kiss 108 from my wife's car with a Ted Talk, while I was parked on the side of the road on the opposite side of the yard.
Getting to the question: I always wondered how that little transmitter interfered with HD Radios. If I put that Ted Talk on and drove around my town, would it interfere with WXKS-HD1 or just the analog WXKS-FM? Or WEEI-FM/HD-1 in reference to this thread. The same for a Tropo. How do the interruptions differ between Analog and HD Radio?
