850LM Universal Gate and Garage Door Opener Receiver

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.

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).

This unit uses relays and can operate up to 3 operators. What this means is there is a mechanical switch inside and it'll run any garage door opener that can use a wall button. I opted to wire in a 12 volt transformer to power mine. Just connect the relay contacts to the operator where you would a wall button (you can keep the wall button as well). I'm using mine to run 2 garage door operators. This wireless system works separately from your garage door opener - so you'll be directly "learning" or teaching the 850LM your remotes - so if you have older remotes that don't work with the liftmaster yellow learning button you'll need to upgrade to a Security + 2.0 remote. You can mount it near your garage door operators where you have power available (If you choose to use a transformer for power) and you don't have to make long wire runs for the trigger wires to the operators. Couple this convenience with the ability to relocate its antenna to the exterior of your building (especially if you have a metal building that blocks the signal) and your range should improve drastically. Use a simple coax cable and put the antenna outside. Or you could opt to put the 850LM in a more easily accessible location so you can reach your learn buttons more easily... just run wires accordingly.

This item works well

Purchased this receiver for an early 90s (I’m guessing, older potentially) sears opener. It had a learn button but after unsuccessfully trying 2 different ‘universal’ remotes I found this. Simple installation, only hang up was needing to purchase a 12v power supply.

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.

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

The range of this device is very limited. It would only work within about 4 feet of my steel garage door. This was not good enough distance to operate the garage door from a vehicle outside the garage. With the door open the range was only about 15 feet.

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