# Any garage door experts (transmitter question)? **URL:** \ **Category:** Factual Questions\ **Created:** [May 9, 2006, 3:39am UTC](https://boards.straightdope.com/t/any-garage-door-experts-transmitter-question/356016 "2006-05-09T03:39:08Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![CaveMike](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cavemike/32/16379_2.png) [@CaveMike](https://boards.straightdope.com/u/CaveMike)\ **Post date:** [May 9, 2006, 3:39am UTC](https://boards.straightdope.com/t/any-garage-door-experts-transmitter-question/356016/1 "2006-05-09T03:39:08Z")
I have a very old electric garage door opener. I don’t know exactly how old and that is apparently an important piece of information. Everything still works great except for the transmitters. I have been using the universal, learning transmitter built into my car, but now I need an regular, external transmitter. Searching around the internet has not helped much. The transmitters are no longer made, but I might be able to buy replacements if I knew the age of my originals. I have tried calling a few places and come up empty handed. I have a few more places that I can try calling. Today I went out and bought a couple of different programable transmitters. [This](http://www.sears.com/sr/javasr/product.do?BV_UseBVCookie=Yes&vertical=TOOL&pid=00953778000) one which has 9 2-way DIPs and 4 2-way DIPs for selecting the brand. And [this](http://www.sears.com/sr/javasr/product.do?BV_UseBVCookie=Yes&vertical=TOOL&pid=00953698000) one which has 9 3-way DIPs. Unfortunately, my transmitter and receiever only have 6 2-way DIPs. I’ve tried setting the extra 3 DIPs to all positions, but that didn’t work. The opener is an ElectroLift Executive manufactured by Chamberlain and distributed by Sears. Main model number is G-6446, remote transmitter is G-3446, and receiever is G-2446. I have the original manual, but there is no date listed. Does anyone have any ideas? Perhaps someone knows the protocol and can suggest what to set the DIPs to. Or perhaps someone can help me pinpoint the age? I realize that I can replace both the transmitter and receiever with a new kit, but I would like to minimize the money I spend since I am selling the house (hence the need for the external transmitters). Finally, is it possible to buy an external, universal, learning transmitter like the one I have in my car? ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [May 9, 2006, 3:54am UTC](https://boards.straightdope.com/t/any-garage-door-experts-transmitter-question/356016/2 "2006-05-09T03:54:26Z")
Sears? They are quite good at providing parts for old items. I’d talk to them first. The next best thing is a replacement transmitter and receiver. The receiver connects to the same place as the internal wired pushbutton. Hardly any work to install. Obviously, not as cheap as a transmitter alone, but not too bad. ---
**Author:** ![Arjuna34](https://avatars.discourse-cdn.com/v4/letter/a/eb8c5e/32.png) [@Arjuna34](https://boards.straightdope.com/u/Arjuna34)\ **Post date:** [May 9, 2006, 5:17am UTC](https://boards.straightdope.com/t/any-garage-door-experts-transmitter-question/356016/3 "2006-05-09T05:17:13Z")
What’s the FCC ID? It should be somewhere on the transmitter. That would help in trying to figure out how it works. ---
**Author:** ![CaveMike](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cavemike/32/16379_2.png) [@CaveMike](https://boards.straightdope.com/u/CaveMike)\ **Post date:** [May 9, 2006, 12:35pm UTC](https://boards.straightdope.com/t/any-garage-door-experts-transmitter-question/356016/4 "2006-05-09T12:35:00Z")
> [@ftg](#): > > The next best thing is a replacement transmitter and receiver. The receiver connects to the same place as the internal wired pushbutton. Hardly any work to install. I was thinking about that too, but that leads to another set of questions. My receiever only has a 2-wire connection (I assume power comes over those wires). The receivers I saw at the store plug in to the electrical outlet as well as use two wires. I wasn’t sure if I could use a new receiever. > [@Arjuna34](#): > > What’s the FCC ID? It should be somewhere on the transmitter. That would help in trying to figure out how it works. I don’t see an FCC ID on the transmitter. Just an FCC statement about it complying to FCC rules part 15. I had expected somewhere there to be a frequency that it uses. However, in the process of seeking out the FCC ID, I did notice a date stamp on the PCB: Sept 14, 1977. There is also a patent number: 3,906,348 and I looked it up [here](http://patft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=3,906,348.PN.&OS=PN/3,906,348&RS=PN/3,906,348). ---
**Author:** ![CaveMike](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cavemike/32/16379_2.png) [@CaveMike](https://boards.straightdope.com/u/CaveMike)\ **Post date:** [May 9, 2006, 12:39pm UTC](https://boards.straightdope.com/t/any-garage-door-experts-transmitter-question/356016/5 "2006-05-09T12:39:10Z")
From the patent app: > [@](#): > > …movable contacts 14c and 14e and 14f are connected to ground… Does that explain why my controller only has 6 DIPs instead of 8 or 9? Because 3 of them are hard-coded to 0? ---
**Author:** ![FatBaldGuy](https://avatars.discourse-cdn.com/v4/letter/f/ecd19e/32.png) [@FatBaldGuy](https://boards.straightdope.com/u/FatBaldGuy)\ **Post date:** [May 9, 2006, 2:05pm UTC](https://boards.straightdope.com/t/any-garage-door-experts-transmitter-question/356016/6 "2006-05-09T14:05:04Z")
The dip switches on your current transmitter/receiver are for setting the “combination” for your opener, so that other garage doors on the same frequency don’t open and close with your transmitter and vice-versa. They should be set to the same codes on both the receiver and transmitter. How this works with the universal model you bought, I’m not sure. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [May 9, 2006, 5:12pm UTC](https://boards.straightdope.com/t/any-garage-door-experts-transmitter-question/356016/7 "2006-05-09T17:12:00Z")
> [@CaveMike](#): > > I was thinking about that too, but that leads to another set of questions. My receiever only has a 2-wire connection (I assume power comes over those wires). The receivers I saw at the store plug in to the electrical outlet as well as use two wires. I wasn’t sure if I could use a new receiever. Hmm. So you seem to have a separate receiver unit? The ones I’ve installed always had the receiver built into the head unit. Do you have a pushbutton? Is there a wiring connector for one? These are normally wired using 2 lead “doorbell” wire. That’s where the replacement unit would connect to. ---
**Author:** ![CaveMike](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cavemike/32/16379_2.png) [@CaveMike](https://boards.straightdope.com/u/CaveMike)\ **Post date:** [May 10, 2006, 1:15am UTC](https://boards.straightdope.com/t/any-garage-door-experts-transmitter-question/356016/8 "2006-05-10T01:15:23Z")
> [@ftg](#): > > Hmm. So you seem to have a separate receiver unit? The ones I’ve installed always had the receiver built into the head unit. > > Do you have a pushbutton? Is there a wiring connector for one? These are normally wired using 2 lead “doorbell” wire. That’s where the replacement unit would connect to. Yep, the receiver doubles as the garage push-button and this unit connects to the motor assembly using 2 wires. From what I have read, this is not unusual in very old systems, but is unusual since then. ---
**Author:** ![rbroome](https://avatars.discourse-cdn.com/v4/letter/r/838e76/32.png) [@rbroome](https://boards.straightdope.com/u/rbroome)\ **Post date:** [May 10, 2006, 12:02pm UTC](https://boards.straightdope.com/t/any-garage-door-experts-transmitter-question/356016/9 "2006-05-10T12:02:54Z")
> [@CaveMike](#): > > Yep, the receiver doubles as the garage push-button and this unit connects to the motor assembly using 2 wires. From what I have read, this is not unusual in very old systems, but is unusual since then. The simple solution to your problem is a new receiver. Most old garage door openers, perhaps they still do this today, trigger the motor by simply shorting across the terminals. You can test this by disconnecting the two wires to the motor and shorting the contacts. The garage door should open. This means that virtually any receiver will work. The coding and security is built into the receiver and not the motor. buy a new receiver and transmitter combiniation at Sears or the local HW store, and it should just work. BTW, hang on to that old opener! The units sold in the last 10-15 years tend to use plastic gears and other cheapo parts. The older units have metal gears-that is why they are still working long after the newer units have ground themselves to fluffy lint. ---
**Author:** ![CaveMike](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cavemike/32/16379_2.png) [@CaveMike](https://boards.straightdope.com/u/CaveMike)\ **Post date:** [May 10, 2006, 8:21pm UTC](https://boards.straightdope.com/t/any-garage-door-experts-transmitter-question/356016/10 "2006-05-10T20:21:35Z")
> [@rbroome](#): > > The simple solution to your problem is a new receiver. Most old garage door openers, perhaps they still do this today, trigger the motor by simply shorting across the terminals. You can test this by disconnecting the two wires to the motor and shorting the contacts. The garage door should open. This means that virtually any receiver will work. The coding and security is built into the receiver and not the motor. > > buy a new receiver and transmitter combiniation at Sears or the local HW store, and it should just work. > > BTW, hang on to that old opener! The units sold in the last 10-15 years tend to use plastic gears and other cheapo parts. The older units have metal gears-that is why they are still working long after the newer units have ground themselves to fluffy lint. Thanks **rbroome**! I didn’t think the receiver angle all the way through to realize that it is just a remote switch. I was afraid of hooking my new receiever up to the old opener and then frying it with some unexpected voltage. That is great advice to keep the old opener. I have heard the same thing from another garage door expert and several friends have lamented that their openers only last a few years before the plastic gears become stripped. ---
**Author:** ![CaveMike](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cavemike/32/16379_2.png) [@CaveMike](https://boards.straightdope.com/u/CaveMike)\ **Post date:** [May 17, 2006, 2:11am UTC](https://boards.straightdope.com/t/any-garage-door-experts-transmitter-question/356016/11 "2006-05-17T02:11:23Z")
> [@rbroome](#): > > buy a new receiver and transmitter combiniation at Sears or the local HW store, and it should just work. Both of the receiever kits that I found at the store claim to only work on systems made after 1983. Any idea if they will actually work and this is just CYA? Or is it possible that they indeed will not work? ---
**Author:** ![Rhubarb](https://avatars.discourse-cdn.com/v4/letter/r/59ef9b/32.png) [@Rhubarb](https://boards.straightdope.com/u/Rhubarb)\ **Post date:** [May 17, 2006, 3:20am UTC](https://boards.straightdope.com/t/any-garage-door-experts-transmitter-question/356016/12 "2006-05-17T03:20:54Z")
> [@CaveMike](#): > > Both of the receiever kits that I found at the store claim to only work on systems made after 1983. Any idea if they will actually work and this is just CYA? Or is it possible that they indeed will not work? I think (My CYA statement) that means that they won’t work with transmitters made before 1983. I would assume that some momentous event in garage door technology happened that year (coded transmission, change of frequency, whatever). If you buy a new transmitter, it should be okay. THe only thing to really be certain of is that the receiver has some type of dry contact output that will momentarily short the contacts on your door opener. If necessary, the receiver can be mounted anywhere and just have a two-conductor wire run to the same terminals that the pushbutton inside your garage is connected to. Good luck. ps - my bil just sold a house that apparently had the original opener - approximately a 1957 model. It still worked great. ---
**Author:** ![CaveMike](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cavemike/32/16379_2.png) [@CaveMike](https://boards.straightdope.com/u/CaveMike)\ **Post date:** [June 8, 2006, 12:53am UTC](https://boards.straightdope.com/t/any-garage-door-experts-transmitter-question/356016/13 "2006-06-08T00:53:51Z")
I had given up and called a garage-door guy out. He just added a receiver in parallel and everything works great. I guess I could have done that all along. Thanks everyone!