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DonLibes
Premium,ExMod 2001
join:2003-01-19

ideas for improving garage door opener reception?

My transmitter has to be very close to my garage door opener before the receiver will 'hear' it. I've tried moving the receiver around the garage but with little improvement. In fact, when I move it closer to the door, the receiver performs worse, perhaps because it's shielded by the wall.

The receiving antenna is just a short (roughly 5 inches) wire that hangs down. Can I solder on an additional length of wire to improve reception? Is there an optimal orientation? Can I poke a hole through the wall and feed the augmented antenna outside? Any other ideas?


Phil
Rojo Sol
Premium
join:2001-06-11
Downers Grove, IL
kudos:2
The receiving antenna is several feet long on mine so and I'm able to open my garage door from about 40 yards out. You also might check the batteries in the remote.

DonLibes
Premium,ExMod 2001
join:2003-01-19
The transmitter is built in to my car and the receiver is plugged in an outlet so it's definitely not battery related!


Phil
Rojo Sol
Premium
join:2001-06-11
Downers Grove, IL
kudos:2
My wife's car has the built in transmitter as well and in her case she also needed to be very close to the garage to open it (10-20 feet).


Hall
Premium,MVM
join:2000-04-28
Germantown, OH
kudos:2
reply to DonLibes
Garage door metal or wood ? If it's metal, maybe try pointing the antenna *up*. This way, it may get better reception through the wood and shingles vs the metal door.


fireflier
Coffee. . .Need Coffee
Premium
join:2001-05-25
Limbo
reply to DonLibes
Has it always done this? Has it recently started?

There are a couple of causes I've seen for this problem. In one case, it was interference from another source. In another case, the opener receiver went "bad". Not completely non-functional but the range was severely restricted.

In theory you could extend the range by determining the frequency it's operating on and choosing a length of wire that's 1, 1/2, or even 1/4 of the wavelength at that frequency. For the typical modern openers, you're looking at a frequency in the 300 - 400 Mhz. That corresponds to around 1 meter long (little less for 400 Mhz) for full wavelength. Of course, then you could be getting into the issue of which orientation of the wire will maximize the distance. Some orientations may do nothing for you. It could turn out to be simple hit or miss.

You're not near a military base by chance are you? »www.ddc.dla.mil/news/2005_02_15_···Door.pdf
--
Tradition: Just because you've always done it that way doesn't mean it's not incredibly stupid. --despair.com


NYR 56
Premium
join:2000-12-05
Smithtown, NY
reply to DonLibes
I was just going to post this exact thread, talk about a strange coincidence as this was the very top one in the forum.

We just installed a metal garage door (in place of a wooden one) and the reception is greatly reduced on at least one of the cars which has the transmitter built in. I was also wondering if adding on some wire to the existing short antenna would help. Do you really have to calculate the length based on the wavelength? I'm not particularly familiar with antenna technology unfortunately. The transmitter that came with the garage door seems to work better than the built in one in the car.


davidg
Good Bye My Friend
Premium,MVM
join:2002-06-15
none
reply to DonLibes
do you have a regular remote for it? if so see if it has better range than the built in remote. if it does, then the problem is the car, not the opener.

FWIW my wife's old impala and my mom's old Tahoe both had to be within 20 ft of the door to open ours. using the original remote she could open her door from over 100 YARDS away. i can open my door from at least 100 yards away too.
--
Lack of Preparation on YOUR Part does NOT Constitute an Emergency on Mine!

Bobcat79
Premium
join:2001-02-04
reply to fireflier
No, you don't want the length to be a full wavelength. You want a 1/2 wavelength (or 1/4 wavelength) antenna.
--
It's nice to be important, but it's more important to be nice.

Mr Matt

join:2008-01-29
Eustis, FL
kudos:1
Reviews:
·Millenicom
·Embarq Now Centu..
·Comcast
·CenturyLink
reply to DonLibes
Chamberlain/Liftmaster offers an external antenna kit that can be attached to the existing antenna on the motor unit. Refer to Antenna Extender Kit Part Number 41A3504. You can download the instructions from their website. Requires installer to drill hole through Garage Wall and mount the antenna assembly on the outside of the wall directly above the Garage Door. Then thread a piece of RG-6 Coax from the Antenna to the wire antenna on the back of the Motor Unit. Ground shield to motor unit.

Regards


davidg
Good Bye My Friend
Premium,MVM
join:2002-06-15
none
reply to Bobcat79
you want 5/8ths wave or 1/4 wave, not 1/2. halfwave antennas can really kill the range.
--
Lack of Preparation on YOUR Part does NOT Constitute an Emergency on Mine!

Phatty

join:2000-05-10
Saint Louis, MO
reply to DonLibes
Just thought I would chime in and say the onboard opener that came in my Honda definitely does not perform as well as a stand alone opener... So their is always a chance you could be suffering from a similar issue.


cowboyro
Premium
join:2000-10-11
Shelton, CT
reply to Bobcat79
said by Bobcat79:

No, you don't want the length to be a full wavelength. You want a 1/2 wavelength (or 1/4 wavelength) antenna.
It all depends on the way the receiver was built and how the impedance is matched inside the receiver. Unless it was very poorly designed then the factory length is the right one. 5" sounds about right (1/4 of 0.75m or 30"), consider there is an additional piece inside plus impedance matching circuits.


eatatjoz
Premium
join:2002-06-16
Mayflower, AR
kudos:3
reply to DonLibes
If it's interference, increasing the antenna length will only increase the noise problem.
You probably need to change the frequency. If you have a 635LM receiver, drop the frequency from 390mhz to 315mhz by replacing the receiver with a 365lm.
--
"I hope you did something important today, 'cause it cost ya another day of your life."


jmycknshk
...bring your green hat

join:2004-07-02
West Chester, PA
reply to DonLibes
Cantenna?

51200853

join:2005-09-08
reply to DonLibes
You need modify it so it don't accept outside interference as required by fcc rule #15


cameronsfx

join:2009-01-08
Panama City, FL
reply to DonLibes
Connect it to your computer and use your iPhone. There is an app for it.


beenthere

@sbcglobal.net
reply to DonLibes
some transmitters have a tuning screw to adjust the transmit frequency. the receiver may have changed frequency due to age. adjust the tuning screw to see if there is an improvement.

retired17
Premium
join:2007-01-24
Anaheim, CA
reply to DonLibes
the receiver may have changed reception frequency due to age and temperature. some remote transmitters have a tuning screw that can be adjusted. try changing it to see if there is an improvement.


anon22

@sbcglobal.net
reply to 51200853
Actually per Part 15 the rule is it has to accept any interference and cannot interfere with any licensed device. In other words if there is any interference that is causing it to not function properly then you have no recourse. Also if you start turning tuning slugs then be prepared for a completely non-functional garage door opener via your wireless remote. You may get lucky but there are risks involved.

said by 51200853:

You need modify it so it don't accept outside interference as required by fcc rule #15


John Galt
Forward, March
Premium
join:2004-09-30
Happy Camp
kudos:8
reply to jmycknshk
said by jmycknshk:

Cantenna?
No.

retired17
Premium
join:2007-01-24
Anaheim, CA
reply to DonLibes
I had great success tuning the car remote to unlock my car door. Before, I had to stand next to the car, now I don't. You just have to make a mark on the remote so that you can put it back to where it was if you mess up.

horsemouth1
Please Clarify My CSP
Premium
join:2002-03-13
canada
reply to DonLibes
We had the same problem.
This worked for us. Move the antenna perpendicular to the door. No shit... worked for us.


peter_m
Premium
join:2005-07-13
Canada, QC

2 edits
reply to DonLibes
Theoretically, the antenna should always be as straight as possible, pointing up, at a right angle with the floor.

Try moving the receiver around the garage, keeping it away from anything metal (including wall insulation that might have aluminum foil in it) or even the door that might be in aluminum. For us it was smackin the middle of the garage, close to the ceiling.

You could try to open the receiver and make sure the antenna is not coiled around the casing for too long before exiting the receiver casing.

Trying different frequencies (if its adjustable) to avoid any interference is also a good idea.

Last resort, I would lengthen the antenna by soldering more wire to the existing tip of the antenna. You could add 2 feet or so and then run tests. Try different lengths by just cutting off 2 inches at a time from the loose end of the extended antenna and testing it again.

Another option is to get a new remote transmitter. If your receiver is a standard one, try getting a new transmitter for it. Look for a key chain model or a car visor model, as long as it's different then the one you currently use, you might get lucky.

Peter


davidg
Good Bye My Friend
Premium,MVM
join:2002-06-15
none

1 recommendation

pointing up or down makes no difference, it is still a vertical polarization. if the transmitter is using horizontal polarization, then the antenna on teh opener should be parallel to the floor. all depends on how the antenna is on both. mismatching the polarization of the antennas can change the signal level by as much as 20db, which is a HUGE difference.
--
Lack of Preparation on YOUR Part does NOT Constitute an Emergency on Mine!


fireflier
Coffee. . .Need Coffee
Premium
join:2001-05-25
Limbo
reply to DonLibes
Cowboybro reminded me of something I'd forgotten:

"Electrically short" antennas (those which are much shorter than a wavelength at the operating frequency) will appear capacitive to the transceiver. Basically this concept is why you see external car cell phone antennas with the little coil near the base--that's inductive compensation for an antenna that would otherwise appear highly capacitive because it is electrically short compared to the frequencies in use by the cell phone base.

Your garage door antenna will also be "electrically short" (given that it's probably 4" -5" and the frequency is 300-400 Mhz, I'm certain of that) and the opener will likely have internal components to provide for proper impedance matching.

Going with a full-wave or half-wave antenna will not appear capacitive (or nearly so) but the inductive compensating components will remain. Thus, you'll lose impedance matching and will probably notice you have either the same range or possibly worse.

As I'd suggested earlier however, if this is a recent problem, you're more likely to solve it by a) finding the source of interfence and eliminating it if possible, or b) replacing the transceiver unit on the opener which may have gone bad.

Is it a Genie opener by chance? That was the brand I was using which developed a very similar problem (it developed, wasn't that way from day one).
--
Tradition: Just because you've always done it that way doesn't mean it's not incredibly stupid. --despair.com


fireflier
Coffee. . .Need Coffee
Premium
join:2001-05-25
Limbo
reply to davidg
Maybe he has a NASA-designed multi-thousand dollar opener system that uses circular polarization?

GdotMikeL

join:2001-04-23
West Chicago, IL
reply to DonLibes
I had this problem once at a previous house- I found if I plugged the opener into an extension cord I could greatly increase the remote's range.


dandeman
Premium,MVM
join:2001-12-05
Chapel Hill, NC
Reviews:
·AT&T Southeast

4 edits
reply to DonLibes
At retired17 said above, there may be a far simpler problem and solution....check that the transmit freq is lined up with the receiver. Many of these remotes (and receivers) are fairly crude and will drift over time or temperature. I can even see reduced range due to receiver drift in extremely cold weather. The range picks back up once the temps come up.

Open up your garage door opener remote to see if there is a tunable slug coil or other tuneable mechanism to set the frequency of the remote to the receiver. On mine this a a slug coil to tune the transmit frequency.

I had to replace the receiver board in my opener some years ago and it was set to a different frequency than the old board/remotes..

So I retuned the remotes.. essentially using the procedure here... With yours go to the limit to where it just barely operates, then go a little further out of range and tweak frequency back and forth around the original setting while holding the open button down. If you get it to work at that increased range, repeat and keep going further out of range and retweaking frequency very slightly back and forth each time, to where you are at the limit at which it will work.

Got mine to work a good 250' away from the door...

When the range drops due to time to replace the battery, if the range doesn't go back up with a new battery, it's re tweak time. Been successful with my 3 remotes every time.. Just mark the original setting before moving it as suggested above.