LiftMaster 850LM Universal Gate and Garage Door Opener Receiver

worked exactly as expected replacing old unit

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).

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.