The back, or inside of the remote should also list the operating frequency.
bp
On 10/28/2014 8:14 AM, Chuck McCown via Af wrote:
Many of these devices are in the 315 or 390 MHz range. I think 315 is
more common.
In free space, the quarter wavelength dimension of 315 MHz is about
18.75 inches.
Measure the wire coming out of the device. That will give you a
hint. It is probably a quarter wavelength long. If so, then you can
extend it with some coax. Make sure the braid of the coax is soldered
to the ground plane of the circuit board. Remove the wire and attach
the center conductor where the wire was soldered.
Get 50 ohm coax with a good copper braid. RG-58 would be a good
choice. Not a sparse braid with foil. You want the old stuff folks
used to use for CB radios.
Outside the garage, you strip the outer sheath of the coax but not the
braid. Push/slide the braid back. It opens up like a chinese finger
pull toy. Then roll it back over the sheath not stripped.
That will leave a length of insulated center conductor. The length of
the insulated center conductor and the length of the braid rolled back
over the sheath should both be a quarter wavelength or a bit shorter.
That makes a cheap and dirty sleeve type dipole. Just make sure that
it is oriented so that you are looking at the broad side of it when
approaching the garage.
- or - Simply extending the wire will work provided you hit the magic
length. I don’t have a clue as to what that length is because it will
depend on the impedance of the receiver, the local RF/ground
conditions on the route out of the garage and outside the garage as
well. I am sure you can find a length that will work but it will take
some experimentation.
On Oct 28, 2014 7:18 AM, "Nate Burke via Af" <af@afmug.com
<mailto:af@afmug.com>> wrote:
I have a double steel garage door with Alumnium siding on the
house. The Remote's have always been finicky since the
opener/door was installed, but now I changed the lights in the
Opener to LED Bulbs, and it's worse. I have to be right under the
opener to use the remote when the bulbs are lit (when they're off,
it seems to work the same as it always has). Seems that I may
need to move/increase gain on the antenna. Some things I found
online talk about running a RG59 cable to the outside, but then
just soldering the original antenna wire on the end of it and just
letting it hang outside. Seems that there should be a better
way. Any suggestions?
Nate
