My garage door opener won't open my garage door when it is shut. When the door is open it will close it and when I am inside the garage it will open and shut the door. Someone told me that the garage door (it's aluminum I think) is stopping the signal. So I tried extending the anntenna from the garage door opener to outside the garage door using speaker wire but that still did not help. How would I extend the current anntenna so that the garage door does not stop the signal?