850LM Universal Gate and Garage Door Opener Receiver

My garage door opener used dip switches to set a security code that matches the code that was set on the remote controls. A long time ago when they were originally sold, that was okay because the likelihood of interception was low and computers were too slow to accomplish a "brute force" password attack (trying every possible number combination until it finds one that works) in a reasonable amount of time. Now computers are fast enough that a handheld computer (like a cellphone, Raspberry Pi, etc) with the proper radio transmitter could force a dip switch door to open in a few minutes. Which means that dip switch garage openers are not secure at all. The solution is "rolling code." More complex passwords that periodically change automatically, and the remotes stay individually linked to the opener even while the password is changing. The 850LM is a rolling code radio receiver meant to replace your door/gate opener's original radio receiver. Physical installation of the 850LM is reasonably easy. I used the included velcro strips to set the receiver (it's about the size of a hamburger) on top of the opener and connected a wire (not included) between the receiver and the door opener's wall button terminals. I tried to use another wire to draw power from the door opener, but I couldn't get that to work so I used a Radio Shack selectable voltage power supply instead. Liftmaster sells a power supply that fits the 850LM. But the receiver accepts anywhere between 9v and 30v AC or DC for power, so you have a lot of options (as long as the plug fits) if you need a power supply and don't want to buy one from LM. The instructions said that cutting off the dangling wire antenna would disable the garage door opener's old radio receiver, but that didn't work at all. I cut the old antenna off, then tested the old remotes, and they still worked! Which I definitely did not want since I was trying to replace the old receiver with a new more secure one. Ultimately I had to take the cover off of the rear (motor) side of the garage opener and unplug the old dip switch radio receiver (a small circuit board) from the motor to completely deactivate it. That shut down the old insecure dip switch system for good and the old remotes no longer worked (which was my goal). The nice thing about the 850LM's antenna is that it attaches to the receiver with the exact same type of screw-on plug that's used for cable TV. Which means that you can also use a coaxial TV cable (along with a small coaxial extension adapter) to place the antenna wherever you want. I was worried that I might get bad reception with the new antenna placed directly on the receiver and the garage opener, so I used a coaxial cable to place the antenna further away from the motor, closer to the driveway, and higher up. I have not used the 850LM enough to say whether the reception distance is any better or worse than the old dip switch receiver, but so far it does work reliably with a new set of compatible remotes and I haven't had any instances where it completely failed to detect the button presses of my remotes (which was a problem that happened intermittently with the old dip switch receiver even when I was right outside of the door).

Replaced a Liftmaster 535LM on a Liftmaster MT5011 operator (opener). Worked perfectly. Wiring is a little unclear in the 850LM papers. The MT5011 has a Common, Push Button and Power terminal. On the 850LM, the Power from the operator connects to the + terminal. The Push Button terminal connects to the NO (Normally Open) terminal on the 850LM. The Common from the Operator needs to connect to the - power terminal with a jumper to the Common terminal on the 850LM. Common and - must be connected together externally. They are not internally jumpered. The device can drive 3 operators, but I only used 1. Paired easily with my new remote. I have 2 doors. I ordered 1 to confirm it would work. I just ordered another one. Installation is about an hour.

This is easy to install. I like that it bypassed completely the old remote sender/receiver (so your existing remotes and car system still works). The new system is independent, using the relay contact closure input of each existing garage opener instead. This universal receiver offers far greater range than our old system. Just remember, you will need a LOT of wire to locate the new receiver in a location that reaches all your garage openers.

This gate receiver ended years of trouble and anguish! our original receiver on our gate system was less than two years old and it did not work more than it did work. After getting the Liftmaster 850LM, we have had exactly ZERO problems in over six months. AND it was a breeze to install and the range on the remotes tripled in distance to the origianal remotes.

4 stars because the seller sent me the wrong item, and then jacked me around for over a week before finally sending the correct item. The items itself works, so can't complain. Note that I bought this with the intention of NOT using it for it's intended purpose as a gate opener. I was experimenting with using it to help my coworkers push buttons remotely rather than have to walk up to the control panel and push a button. In case anyone wants to know: it doesn't matter if you tap or hold the button on the remote... the receiver will always just momentary pulse on/off the channel's relay. Also you cannot simultaneously have 2 channels on at the same time. If for example you pushed 1,2,3 in quick succession on the remote, the receiver would respond with relay1 pulse on/off, a pause of about 1 second, relay2 pulse on/off, another pause, relay3 pulse on/off. So basically, it queue's unique inputs from the remote, and the fastest it can output is once per second . Range is good. The signal pairing is not done with dip switches; refer to the user manual on how to pair. So yea, as I mentioned earlier, I used it for work related stuff. For a while, we had an application that was fritzy and thus required a human to go up to the panel and hit a button to reset it. It was very inconvenient, so I set up this as a quick fix. Worked fine. Eventually the application got fixed and I didn't need the remote anymore. Still, something like this can always come in handy if you know how to use it.

Great product, very easy to install and also easy to program all your vehicles and remotes. I do highly recommend buying this product.

Fonctionne numéro 1 à bonne distance également. Le module est à l’intérieur du garage et à l’extérieur il capte jusqu’a 50 pieds !

Recibe muy bien la señal y da muy buen servicio

Excelente producto, solo funciona con controles de nueva generación que son los multi frecuencia, me funcionó muy bien con un sistema Home link de carro

Excellente porté et les trois fonction Open Close et Stop peuvent être entrer séparément dans une télécommande. Très versatile et simple.

worked exactly as expected replacing old unit