NMO Mount Question

[computerpro3]

I'm switching over from a mag mount to a permanent mount antenna. I'm buying the Antenex CB27 antenna, but I'm confused as to which one of these 40000 mounts to choose. I'll be matching this up to a Uniden Pro 520XL radio.

Now I know that the Uniden has a PL-259 connector, but there is TWENTY FIVE different PL-259 mounts listed here:

Page not found

WTF is the difference between them? Also, when they say loose connector does that mean I have to solder or crimp the connector myself?

[bradthemad]

Your link's busted, but I am familiar with the long list of Antenex NMO mounts. I use the MAB8 on my trunklid, myself.

Differences include the diameter of the hole required (3/8", 1/2", 3/4"), length of the threaded stud that passes through the hole (suitable for a single layer of sheet metal vs. two layers with space in between), type of coax attached to the mount (RG58U, RG58A/U, RG8X, etc.), and the type of fitting attached to the end of the coax (PL-259, BNC, etc.).

The Uniden, like most CB radios, uses a PL-259 connector, but it can be harder to snake coax through tight spaces if it has a big fat connector on the end. The "loose connector" is either a soldered or crimp-on connector and you attach it after you've run the cable. Soldering requires skill, and crimping requires tools. I had barely enough slack to solder in my car, and I'm not that good at soldering anyway, so I bought a crimp tool (Paladin 1317, $45), coax stripper (Paladin 1255, $15), and extra connectors at Fry's, and did my CB and two scanner antenna connectors that way.

[computerpro3]

Will any of these crimpers work?

Search Results for crimper

I don't have a frys near me, so I'm not sure where I could pick one up.

[computerpro3]

Also, I think I'm going for this one:

MAB8XP

But I need to know if it is low-profile enough to fit between my roof and headliner.

[bradthemad]

If you're going with RG-8X coax, an RG-59 crimper MIGHT work. Their diameters are pretty close in size, .022" (RG-59) vs .024" (RG-8X). That Klein coax crimper looks nice, but Radio Shack has a pretty cheap one too, #278-238.

Those mounts are pretty low in profile. All that's on the inside is the coax, a plastic boot where it makes the 90-degree turn, and a skinny little brass backing plate. It fits into about 3/8" to 1/2" vertical space, though you need a little wiggle room to get it into place.

[srtga]

The whole NMO mount has me kind of confused. I want to try a maxrad 2700 but it uses a "motorola type NMO"

I guess it'll make sense once I get it in my hands.

[bradthemad]

It's basically just a 3/4" male-threaded base that is a standard size a lot of antenna makers use. You can get them with a magnetic base, trunk-lip mount, or permanent through-hole mount. Once you have an NMO mount installed, you can swap in different NMO antennas on it without having to re-run the coax.

[srtga]

It's basically just a 3/4" male-threaded base that is a standard size a lot of antenna makers use. You can get them with a magnetic base, trunk-lip mount, or permanent through-hole mount. Once you have an NMO mount installed, you can swap in different NMO antennas on it without having to re-run the coax.

So is the 3/4" brass part the "mount"? I'm guessing that it's flush mounted to the surface with a lock nut on the other side?

[bradthemad]

NMO mount with nothing on it:
dsc00153-a.jpg

NMO mount with rain cap:
dsc00155-a.jpg

Underside of NMO mount:
dsc09030-b.jpg

[Stealth Stalker]

NMO is NMO. The term "Motorola NMO" is redundant, since the M in NMO stands for Motorola. Maxrad and Antenex both work with the same NMO mounts.