It's gotta be someone goofin' around, right? What would make that noise? But it went on another 40 minutes or so after I nearly went mental listening/recording an hour of it. I'd upload the whole thing but it's a big ass MP3 (even in mono) and there's a lot of me scanning back and forth, switching filters in and out, and fiddling with AM and SSB. Maybe it's what's causing birds to fall out of the sky, huh?