[paisanol69]

Originally Posted by itsjusme

Especially when you consider the FCC rules for most electronic devices of this type, it`s sorta straddle of the fence, but says:
1: This device may not cause harmful interference
2: This device must accept any interference received, including interference that may cause undesired operation.

....is that if my name was Bill, and I was known around this website as the '" IPN " , I would be very worried that my neighbors house might be burgled in the near future, and that I might possably be blamed for contributating to that said burglery, since it is now well known by that neighbor, and other neighbors, that MY garage door opener can, and has opened his garage door.

even if it was/could have been caused by a "drive by burgler " I think it could get very messy for Bill, I sure do hope he gets along well with this neighbor!

[Koot]

I believe the people here who believe the problem lies with the owner of the newer garage door opener and remote transmitter may want to seriously reconsider their position. Just because a neighbor has gone for many years without someone elses remote transmitter opening their garage door - it does not mean the problem is with the newer unit. It is almost 100% certain that the culprit is because the neighbor's older unit simply lacks modern day, enhanced security features.

In all likelihood the neighbor's garage door opener is much older. You will find that most garage door opener manufacturers do not support products made prior to 1993, or even more recently made units. Newer units have enhanced safety and security features that comply with new UL safety regulations. Older units lack these security features and do not comply with current regulations. Thus, because older units do not have these safety features and do not comply with current regulations, it is strongly recommend by ALL garage door manufacturers that older units be upgraded.

Older garage door openers use transmitters that send a weak RF (radio frequency) signal within a certain [frequency] range. And the garage door opener's receiver receives the transmitted signal. This is where the problem lies. This old receiver is designed to receive a much broader transmitted signal than new models.

In the very early days of garage door openers, around the 1950s, the transmitters were extremely simple. They sent out a single signal, and the garage door opener responded by opening or closing. As garage door openers became common, the simplicity of this system created a big problem - anyone could drive down the street with a transmitter and open any garage door. They all used the same frequency and there was no security.

By the 1970s, garage door openers had gotten slightly more sophisticated. They began using a controller chip and a DIP switch. A DIP switch has eight tiny switches arranged in a small package and soldered to the circuit board. By setting the DIP switches inside the transmitter, you controlled the code that the transmitter sent. The garage door would only open if the receiver's DIP switch were set to the same pattern. This provided some level of security, but not much. Eight DIP switches provide only 256 possible combinations. That's enough to keep several neighbors from opening each other's doors, but not enough to provide any real security. With such a broad (receiver) range of frequency it's common for these older garage door openers' receiver to open a neighbor's garage door as often as - every time a modern, newer remote is used. Remote-entry transmitters and receivers have gotten a lot more sophisticated since then.

With the remote keyless-entry systems that you find used for garage openers and cars today, security is a big issue. If people could easily open other people's cars in a crowded parking lot at the mall, it would be a real problem. The same applies to garage doors. And with the proliferation of radio scanners, you also need to prevent people from "capturing" the code that your transmitter sends. Once they have your code, they can simply re-transmit it to open your garage door or car.

The controller chip in any modern controller uses something called a hopping code or a rolling code to provide security. For example, a new system that uses a 40-bit rolling code provides about 1 trillion possible codes. The transmitter's controller chip has a memory location that holds the current 40-bit code. When you push a button on the remote transmitter it sends that 40-bit code along with a function code that tells the garage door opener's receiver what to do (open the door or close the door). The receiver's controller chip also has a memory location that holds the current 40-bit code. If the receiver gets the 40-bit code it expects, then it performs the requested function. If not, it does nothing. Both the transmitter and the receiver use the same pseudo-random number generator. When the transmitter sends a 40-bit code, it uses the pseudo-random number generator to pick a new code, which it stores in memory. On the other end, when the receiver receives a valid code, it uses the same pseudo-random number generator to pick a new one. In this way, the transmitter and the receiver are synchronized. The receiver only opens the door if it receives the code it expects.

Given a 40-bit code and up to 256 levels of look-ahead in the pseudo-random number generator to avoid desynchronization, there is a one-in-a-billion chance of your transmitter opening a neighbor's garage door...IF the neighbor also has modern equipment that provides them with security. When you take into account the fact that garage door manufacturers can use different systems and different frequency ranges, and that the newest systems use many more bits, you can see that it is nearly impossible for any given transmitter to open any other garage door...unless a neighbor's equipment is old and lacks the security new units have.

You can also see that code capturing will not work with a rolling code transmitter. Older garage door transmitters sent the same 8-bit code based on the pattern set on the DIP switches. Someone could capture the code with a radio scanner and easily re-transmit it to open the door. With a rolling code, capturing the transmission is useless. There is no way to predict which random number the transmitter and receiver have chosen to use as the next code, so re-transmitting the captured code has no effect. With trillions of possibilities, there is also no way to scan through all the codes because it would take years to do that.

The question that needs to be answered is - who's problem is this? Is it the problem of the owner that owns the new equipment, or is it the problem of the owner that owns the old outdated equipment?

[JohnWill]

Originally Posted by paisanol69

is just because my neighbore decided to upgrade/replace his garage door opener, do not mean that I should have to also.

Whats next? He/she decide to paint their house, so now I must follow suit?

That is/was the point of my last post!!

You assume facts not in evidence. The reason your neighbor's opener affects your door could be because of a defect in the design or hardware of your receiver, or even a configuration issue. Trying to simply blame the neighbor because his installation is newer probably won't be very effective.

Edit: I see I was preempted by the previous post in a much more complete manner.

[Elvandil]

All used the same frequency? LOL. I really haven't heard anything so ridiculous in a long time. Thanks for the laugh. There may be other gems, but no one is going to read that whole post, anyway.

In any case, the newer digital transmitters can conceivably send out an encoded signal at the same frequency as the receiver and make it respond even though it is not even digital.

But even those old ones had chokes to tune the frequency since they tended to drift with time. So he should be able to make a minor change to his.

(PS. Did you know that back then, everyone had the same telephone number, too? AND, the same address? You can't imagine the chaos it caused. )

[JohnWill]

I'm sure there's a resolution, it just depends on how technical the users are.

[Koot]

Originally Posted by Elvandil

All used the same frequency? LOL. I really haven't heard anything so ridiculous in a long time. Thanks for the laugh. There may be other gems, but no one is going to read that whole post, anyway.

In any case, the newer digital transmitters can conceivably send out an encoded signal at the same frequency as the receiver and make it respond even though it is not even digital.

But even those old ones had chokes to tune the frequency since they tended to drift with time. So he should be able to make a minor change to his.

(PS. Did you know that back then, everyone had the same telephone number, too? AND, the same address? You can't imagine the chaos it caused. )

I assume you are talking about my post. The very old garage door transmitters did indeed use a single frequency. Each unit had its own frequency, but the manufacturers probably didn't use more than a couple dozen different frequencies within the [frequency] range. What is so ridiculous about what I stated? It's just the way it was... As garage door openers became more popular it was common to have numerous openers in the neighborhood using one of the same small number of frequencies. Also, with the receivers not having much signal rejection capabilities a signal that was transmitted close to the designed frequency oftentimes opened the garage door at a nearby neighbor's house.

I'm curious why you think no one will read my entire post. It's their loss if they want to learn what the problem is...and it's your loss since it's obvious that you're in way over your head!

Do you have anything to offer other than suggesting that someone should tune the chokes in the old unit's receiver? Are you suggesting the owner can do this? Are you suggesting that a garage door technician will remove components on the receiver's printed circuit board to isolate the receiver circuit and then use a DIP meter to fine-tune chokes to hopefully reject unwanted signals? Yeah, right!!! Tell me, what would cause a garage door opener receiver's tuned circuit to drift? Do you really think even a seasoned garage door technician has the knowledge, equipment or time to attempt to make an old garage door opener's receiver reject a signal it was [actually] designed to receive?

Thanks for the laugh!

[Elvandil]

Thank you.

Though I didn't read that massive post, I suspect that you are trying to "teach" something again. Thanks, but if I'm going to take the time to learn something, it would first have to be true. And I seriously doubt there is a single thing that I would like to know from you. So, look for other victims, I mean, "students", to impart your strange catechism to.

Editing your post to remove the funny parts was not fair at all.

Classic:

he very old garage door transmitters did indeed use a single frequency. Each unit had its own frequency, but the manufacturers probably didn't use more than a couple dozen different frequencies within the [frequency] range.

Any idiot can cut and paste huge posts that no one will read. But you are a thief, pure and simple, and you have absolutely nothing to teach me.

For example:

http://auto.howstuffworks.com/remote-entry2.htm

[Koot]

Originally Posted by Elvandil

Thank you.

Though I didn't read that massive post, I suspect that you are trying to "teach" something again. Thanks, but if I'm going to take the time to learn something, it would first have to be true. And I seriously doubt there is a single thing that I would like to know from you. So, look for other victims, I mean, "students", to impart your strange catechism to.

Editing your post to remove the funny parts was not fair at all.

Classic:

Massive post! Probably less just a few minutes or reading...

You sound to me like someone that could stand to learn something about the topic instead of mouthing off rude comments to someone willing to share helpful and ACCURATE information. Much of the information I shared is available with a little Google searching.

I feel sorry for you that you cannot handle the truth. I also feel sorry for you that you are unwilling (or unable) to read a handful of paragraphs. But, you are all too anxious to ridicule others. Good work pal.

[Elvandil]

Use your time to look up the word "plagiarism". It is illegal, you know.

The majority of our members are honest people. We like it that way.

[Koot]

Originally Posted by Elvandil

Use your time to look up the word "plagiarism". It is illegal, you know.

The majority of our members are honest people. We like it that way.

Oh geez. Nice twist! You're a strange, strange fellow.

[wacor]

careful men or this will end up in CD

[Koot]

Originally Posted by wacor

careful men or this will end up in CD

There's no need for that to happen. Hopefully this thread can get back on topic.

I have stated my opinion that I believe your neighbor's garage door opener is old and prone to operate from other people's remote transmitters because the old unit lacks modern security standards. This opinion can be confirmed by an experienced overhead door technician "if" your neighbor is willing to request a service call...

Moving on - it may be interesting to discuss who is responsible for resolving the problem if repairing or replacing the neighbor's opener is required. Also, it may be interesting to discuss if you (or another neighbor) could be held liable for harm or theft caused by your (or someone elses) remote transmitter operating your neighbor's old garage door opener.

[itsjusme]

Originally Posted by wacor

garage opener is opening the neighbors door too..........................

You may have actually done your neighbor a favor, he now knows that his security could easily be compromised by someone with a transmitter like yours. As far as whose responsibility it is to fix it? I`m not 100% sure but i believe as long as your transmitter is operating in the specified band, within the specified frequency range for this type device, within the power output levels specified for this type device, not emitting out of band harmonics, and otherwise functioning as it was designed to, it is up to your neighbor to resolve the problem. Of course the average installer probably wont have the equipment or knowledge to check much of that. As far as the legal liability in the event of a break in, the FCC regulations i mentioned above would come into play there i imagine, who won would depend on who had the best lawyer if it came to that. LOL It may be possible to shield the side of his unit facing you with foil or sheet metal to try and block your signal, depending on his location in respect to your house(on your side or directly across the street?) Or experiment with which direction you point your remote to see if maybe some certain direction may open yours and not his. Good luck, it`s no fun fussing with neighbors, maybe ya`ll can work it out. But if you`re hearing about this from others and the neighbor hasnt approached you yet, .....well, good luck.

[JohnWill]

I remember when I was a kid in my teens driving around and just pushing the garage door opener button for every house, you'd be amazed at how many doors we opened!

[itsjusme]

Originally Posted by JohnWill

I remember when I was a kid in my teens driving around and just pushing the garage door opener button for every house, you'd be amazed at how many doors we opened!

LOL Yeah, i`m guilty too. Back then they operated on a frequency and had a receiver that was easily overridden. And we had a remote of sorts. If you had a CB with a big amplifier, you could open doors for blocks. LOL Most of those CB amps put out dirty signals with terrible harmonics, it would overload the receiver front end and drive em nuts.