Garage Door Opener Antenna Extension

How to video showing a relatively simple way to improve the reception of signal sent by the remote control at the door opener.
Also see second related video - Garage Door Opener Antenna Extension - Coaxial Cable Preparation - uploaded July 8, 2017 • Garage Door Opener Ant...
Our garage door opener worked perfectly for a couple of years. After trying different things (changing battery, having the remotes tested by the garage door company, noting how changes in weather affected the operation) I was convinced the signal sent by the remotes have become weaker with age. This was complicated by the metal foil insulation, metal garage door and metal roof on the house shielding the signal from the short antenna on the opener.