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Do you have problem's with the range of your garage door opener? It might not be your car.
If you have a remote control garage door opener, with external antenna, you can extend the range of operation with this simple DIY tip:
If you see a short length of wire coming off your unit, or coiled up on top, chances are that's your antenna.
Make sure that it is extended as much as possible, and as straight as possible as follows:
1) Obtain a simple plastic straw and small piece of duct tape
2) Climbing up to your garage door unit, locate the length of antenna wire
3) Extend the antenna wire and slip the plastic straw around it, route the wire through the straw, and out the other end.
4) Secure the end of the wire with the duct tape so it does not slip out
5) The wire should be nice and straight
That's it!
Why it works
Garage door openers typically operate in the 300 to 400 MHz range:
http://en.wikipedia.org/wiki/Garage_door_opener
What this means is that the wavelength of the radio waves are on the order of
wave length = phase velocity / frequency
For radio, the phase velocity is the speed of light, or approximately 3 x 10^8 m/s.
At 350,000,000 Hz, wave length is thus approximately 80 centimeters.
http://en.wikipedia.org/wiki/Wavelength
Without going into the Electrical Engineering, a typical low-cost antenna is called a quarter wave dipole, which is matched to wavelenth / 4 in length. This is a fairly cheap design (wire) that works well enough for the application (garage door opener).
http://en.wikipedia.org/wiki/Dipole_antenna#Short_dipole
For our notional 400 MHz system, a quarter wave is about 20 centimeters, or about a foot.
Since the antenna on your garage door opener is tuned to receive these signals, the closer you can get to match the transmitter in terms of signal (quarter wave dipole), the better. The antenna (wire) will work best if it's straight. The plastic straw helps to do that.
Try it - it works.
If you have a remote control garage door opener, with external antenna, you can extend the range of operation with this simple DIY tip:
If you see a short length of wire coming off your unit, or coiled up on top, chances are that's your antenna.
Make sure that it is extended as much as possible, and as straight as possible as follows:
1) Obtain a simple plastic straw and small piece of duct tape
2) Climbing up to your garage door unit, locate the length of antenna wire
3) Extend the antenna wire and slip the plastic straw around it, route the wire through the straw, and out the other end.
4) Secure the end of the wire with the duct tape so it does not slip out
5) The wire should be nice and straight
That's it!
Why it works
Garage door openers typically operate in the 300 to 400 MHz range:
http://en.wikipedia.org/wiki/Garage_door_opener
What this means is that the wavelength of the radio waves are on the order of
wave length = phase velocity / frequency
For radio, the phase velocity is the speed of light, or approximately 3 x 10^8 m/s.
At 350,000,000 Hz, wave length is thus approximately 80 centimeters.
http://en.wikipedia.org/wiki/Wavelength
Without going into the Electrical Engineering, a typical low-cost antenna is called a quarter wave dipole, which is matched to wavelenth / 4 in length. This is a fairly cheap design (wire) that works well enough for the application (garage door opener).
http://en.wikipedia.org/wiki/Dipole_antenna#Short_dipole
For our notional 400 MHz system, a quarter wave is about 20 centimeters, or about a foot.
Since the antenna on your garage door opener is tuned to receive these signals, the closer you can get to match the transmitter in terms of signal (quarter wave dipole), the better. The antenna (wire) will work best if it's straight. The plastic straw helps to do that.
Try it - it works.
