The picture rolls and displays a wiggly white line running down the left, right or both sides of the screen. The Descrambler unit restores the pulse synchronization making it possible for vertical and horizontal video and audio signal to stabilize. First , of course, trust your own judgment. A company you can trust will be one that has at least a 30 day Guaranty and a 90 day warranty on their products. Offers a variety of equipment for most areas of the country and some areas of the world.
Staff are capable of answering most technical questions.
This is a short list.