My TV hookup involves an older TV, a converter box, and a set-top digital antenna. The antenna is about seven feet above the floor and works pretty well – except when there’s a helicopter in the area. (I live within a mile or so of two fairly major highways, and about two miles from two TV stations, but have no specific explanation for why I have helicopters going by several times a week.)
Why does helicopter activity interfere with digital TV reception? Is it the turbulence the blades create (that doesn’t make sense, does it?) or something about its instruments or what?
The tv station’s signals are probably hitting the helicopter and being reflected to your antenna. Your tuner is getting the direct signal from the transmitter, as well as the reflected signal(s) off the heli. This is called multipath interference, and the digital tuner does not like that. It will often lock up or refuse to decode info at all.
It’s about the same setup that my mother has but in her case the picture goes berserk whenever it’s bad weather, especially if it blows much.
I remember from when Swedish TV transmitters started going digital a couple of years ago that everything would be soo fine, perfect picture and all that. The truth is that it turned out to be a case of perfect picture or no picture at all.
the helicopter or airplanes or blimps or trucks will all reflect tv signals either analog or digital. a static reflector like a building, wall or mountain is always there and you can compensate for it more easily, a moving reflector is more of a problem. people have both worked on aiming and shielding their antennas to find solutions. the effect on digital signals is more noticeable due to the digital processing.