Update: I built my resonant loop antenna over the weekend, and the noise came back strong last night. Took the antenna around the block and was positively able to isolate the house (and the room) that the noise is coming from. Surprisingly, it was NOT Neon-guy. The noise appears to be coming from a large TV mounted on the wall of the living room on the 2nd floor of this home. The noise starts at about 2460 KHz and starts to die off just above 8000 KHz. The directional nature of the noise suggests that it is not a power-supply issue, which would likely be leaking into the electrical system of the house to radiate. Unfortunately, I don't know very much about how a television set could be radiating RF, especially at those frequencies. My guess is that the RF noise is reflecting off of whatever (ineffective) RF shielding exists at the back of the TV set, and propagating throughout the neighborhood. Mike says he's going to approach the guy, so I'm going to let that play out, and stay out of things for now. If it continues after that, or if we get a negative response (which I don't really expect), then I guess I'll have to escalate things. Anyone ever heard something like this from a TV before? I'd like be able to offer a solution if I can, not just a complaint.