Garage Door Opener Antenna Extension - Coaxial Cable Preparation
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- Опубліковано 30 вер 2024
- Supplemental information for my original video - Garage Door Opener Antenna Extension
• Garage Door Opener Ant... - uploaded Dec 13, 2012
More information is given regarding Coaxial Cable End Preparation for this application and how it was connected to the circuit board.
The length of the antenna wire is important for receivers that are tuned to a single frequency (or a very narrow band of frequencies). These receivers usually use antenna lengths on the order of a quarter of a wavelength, (or and odd integer multiple of a quarter of a wavelength - 1/4, 3/4, 5/4, etc.). By increasing the antenna length to anything other than an odd multiple of a quarter of a wavelength, you reduce the antenna's effective gain.
By grounding the shield at the circuit board, the effective antenna length is simply the length of unshielded wire that hangs off the other end of the coaxial cable. In addition, the grounded shield can significantly reduce the amount of interference picked up near the opener.
after replacing my 8 foot neon bulbs with LED's the door opener quit working outside the house. The LED's operate at the same 300mhz range as the door opener. i connected the center of the coax to the antenna wire after trimming the original wire off, the soldered the connection. I then covered the wire to the board (2") with aluminum furnace tape to create my own shielding. For the antenna outside the house I just stripped away the shielding part of the cable leaving the center wire uncovered as the new antenna. I left 9" of the center wire without shielding and mounted to a simple L bracket to get it away from the metal exterior of the house. 312mhz, quarter wave requires a 9" antenna. I grounded the coax to the exterior of my metal skin house. Opener now works at 100 feet with lights off and 25 feet with light on. thanks for the video, sent me down the right track to solve my problem...
Next time you are preparing the coax, instead of using an awl to unbraid the shield, separate the braid with the awl near the outside cover and pull the inner conductor and insulation through the braid. You can then pull and twist the braid to form a conductor for grounding or soldering (if desired).
Couldn't you just connect the center coaxial wire to the OEM antenna wire?
not to be an ass but coax cable conductors arent copper they are steel clad in copper... i service garage doors/openers professionally and most of the time if your remotes arent working at a distance its typically caused by the lightbulbs being used in the motorhead. or in light fixtures surrounding the motor on the ceiling. both led and fluorescent bulbs emit rf interference. genie and chamberlain both have shielded led bulbs that dont cause interference. but standard incandescent bulbs are best to use if you can find them. as for coax. the only way you get ofc copper coax is to order it that way. typically its coax made for aerials and wont work well for satelite or cable as its more designed to pick up signal rather than block it out and its very expensive compared to the standard ccs youll get off the shelf
I thought this might solve my erratic garage door opener range, but it turned out the cfl bulbs I used in it created the reduced range by interfering. I thought that was more of a problem with cheap LED's but sure enough, I put some old incandescent bulbs I had lying around and no more problem. The opener's light had IR motion sense and I often found it on when I went into the garage. So when it was on, practically no range.
Works great! Used a couple of leftover 4ft Coax cables with a barrel connector to extend, did not remove the old antenna, the circuit board had an extra hole position to connect a coax. Finally the garage door works from the driveway. Having a barrel connector allows to extend further if needed, but 8ft total was sufficient in my case.
Do you have LED lights in your garage?
The receiver is a super-regenerative circuit. It's very sensitive, but never met a frequency it didn't like. A few years ago, Chrysler and Jeep keyless entry systems would block GDO signals when the car was parked in the garage.
I had one caller who wanted to open his gate from the house, about 150' away. I had him install coax, and use the ground, and run it to a small UHF antenna pointed toward the house. He got amazing range.
Typical frequency range is anywhere from 303mHz to 433mHz. This falls within the UHF TV band and antennas are everywhere.
Does coax impedance and length matters? I never thought about it this way.
Thanks for the comment.
It's good that it wasn't necessary to extend the braid to connect to a ground. The braid and foil are aluminum and will resist soldering efforts. It would have been necessary to use a crimp connector or strip off sufficient jacket to have suitable length.
Well that one caught me off guard. :-) I have soldered many a piece of coax braid. I used to strip it off coax and use it as a shield for long R/C servo leads. I knew the foil was aluminum (of sorts) and just thought the braid was tinned copper. Obviously I have not soldered any in recent years. Bummer! OK... crimp the braid to a piece of copper wire.
ever since I added a large metal carport, the garage door opener is almost useless. I've tried the coax, shielding grounded and ungrounded. No difference. Still experimenting
I connected a spring loaded hole clamp to my wire. It went from not being able to work even when I was right in front of the garage door to working 5 houses away
@@justsaying3594 Can you elaborate on what a 'spring loaded hole clamp' is? I'm trying to fix my garage door antenna reception.
I sort of tried this with limited success. I attached the cable to the original antenna and ran it to the front of the garage door. Is there a reason you attach the copper coax directly to the board? Secondly, I may try to ground the wire. In simple terms, why would the ground, attached to the braid, need to be the length of the old antenna?
Attaching the coax center wire directly to the board is the best way to attach it. The braid isolates the copper from receiving stray signals if it is grounded... not grounded the coax is probably little better than a long wire. The frequency at which these operate, the receivers don't seem to be finicky about antenna length (at lease mine isn't) they just need to receive a signal. Grounding the braid won't hurt a thing. If you can accurately locate ground on the board you can use that point or anywhere that is known to be grounded on the metal frame. You should watch the video again... you misunderstood about the "length of the ground" ... I did not say anything about the length of the ground wire. I said... IF THE COAX IS GROUNDED - The length of the wire (antenna wire) attached to the end of the coax (the end located outside your garage) should be the same length as the original antenna wire you removed from the circuit board. Please subscribe!
Thanks Ron. I'll add this to the long list of projects that need to get done. I'd sub again, but I did it 7 years ago. ;)
UA-cam has the subscription thing screwed up. When I look at your channel page it only shows the last 15 channels you have subscribed to. It is supposed to say "show all" but does't.