What is an NMO mount?

One of the neat things about Solid Signal is that it’s so appealing to so many small groups. This is something you couldn’t really have done before the internet. If this were 1980, and we were out there selling hard-to-find communications gear, we’d probably have a big mail-order catalog. We’d probably concentrate on a few groups like satellite TV fans or CB enthusiasts. Even those fringe groups would have to be pretty big to keep a company like ours going. There’s no way we could concentrate on a group like…

People who mount antennas to their vehicles, but need a universal connector because they’re probably going to change the antenna a few times over.

When you think about it, that’s a pretty small subset of humanity. But, with 7 billion people in the world, even if one-tenth of one percent is interested, that means you have seven million potential customers. And that’s our sweet spot. That’s where we do our best work.

If you’re looking for a base you can permanently mount to your vehicle while still being able to change the antenna, come to Solid Signal. Turns out we have over 600 parts and accessories for that very need. But you already knew that. For the rest of us, let’s talk about what this mounting system is and why you would want one.

NMM mount? Or is it NMO mount?

The mounting base you see in the picture above is called an “NMO mount.” For reasons which the internet cannot seem to explain, “NMO” stands for “New Motorola Mount.”

Yeah I don’t get it either.

All you need to know is that at one point there was this company called “Motorola.” The name is still out there but the original company has been broken up and sold. You might remember them for their phones in the ’00s, but they actually had a start making car radios. (That sort of explains the name, when you realize “Victrola” was an old brand of music player. So the name means “Victrola for your Motor Car.”)

In fact, Motorola was so successful making car radios back in the day that everyone tried to copy them. Think like Apple today, everyone else tries to do what they do, and if there’s a part you need for your iOS device, there are plenty of companies that make them. Exactly like that.

So they had a system for mounting their antennas which, you have to assume, everyone called the “Motorola mount.” At some point the old-style mount went away (like Apple killed the original dock connector.) A new mount came in, the “New Motorola Mount.” Even though no one alive seems to know why they call it NMO not NMM, there’s no fighting it. That’s just what they call it.

Why an NMO mount?

The NMO mount has two advantages. First of all if you install it right it has two waterproof seals. There’s a waterproof gasket which goes up against the metal in the vehicle. This keeps the car from rusting out. There’s another waterproof gasket that sits inside the antenna and keeps the connection point waterproof. This means the antenna doesn’t corrode from the inside. Both of these are good thing.

By the way, if you don’t want to drill holes, there are magnetically mounted NMO mounts too. Obviously they’re not quite as secure but then again you don’t have a hole in the car so there’s that.

The other advantage is that when you connect an antenna, it’s not permanent. It’s secure enough, it won’t fall off, but you can disconnect one antenna easily and add another one. It turns out this is a pretty good thing.

Why would you ever change the antenna on your car?

Maybe your police car is old enough that the department actually changed radio frequencies. Perhaps it’s a cell phone antenna that works with one service and not another. Maybe the old antenna was hit with a rock as you were on the way to a call. There are a million reasons why you might change the antenna. The good news is that with an NMO mount you can do it easily.

By the way, NMO mounts also work on boats, and for the same reasons.

If you’re looking for a great selection of cellular and radio antennas, or any other hard-to-find electronics, you owe it to yourself to go to SolidSignal.com. They sponsor this blog and I’d sure appreciate it if you’d give them some consideration.

About the Author

Stuart Sweet
Stuart Sweet is the editor-in-chief of The Solid Signal Blog and a "master plumber" at Signal Group, LLC. He is the author of over 8,000 articles and longform tutorials including many posted here. Reach him by clicking on "Contact the Editor" at the bottom of this page.