What consumer goods cause radio interference of garage door openers openers in the neighborhood do not work unless they are about a foot away from the opener itself not near a military base?

Answer 1

openers that work at 390MHz can be effected from a new radio system the military is putting into service at distances of 50miles or more. The frequency has been allotted to the military since the 50s but was not in use to my knowledge until recently.Garage door companies use that frequency because it penetrates the door easily, the only cure is to change to a new transmitter/receiver on a different frequency.