Making a simple antenna mount for 2″ tube bumpers (or an Aluminess spare tire carrier)

I’ve been using this magnetic 4G antenna with my weBoost 4G-M cellular booster for about a year now. The performance was good, or so I thought. The magnetic bit was strong enough to hold on at interstate speeds without issue, but every single tree branch that I encountered would leave it dangling down, or stuck to my back door.

Upgrading to the Wilson OTR antenna has been on my agenda since I installed the Aluminess spare tire carrier on my back door, but I was never able to find a mounting solution that would accommodate the 2″ tube. I decided to make my own!

In my testing, I saw boosts from -103dbM to -87dbM with the magnetic antenna, and a huge increase to -67dbM with the new antenna! I wanted a permanent mount with the ability to flex out of the way when branches hit the antenna. The OTR includes a spring, but I wanted the actual mount to tilt backward. Here’s how I did it.

Parts and Tools Required

1/8″ thick, 1.5″ wide, aluminum flat bar (we’re only using 7″, I had to buy 36″)
5/16″ Stainless Steel U-bolt
2x 5/16″ fender washers
3x 5/16″ nylock nut
2x 5/16″ acorn nut
5/16″ rubber washer (optional)
90 degree Superstrut brace
Zip ties

Center Punch
Electrical tape
Drill
3/8″ drill bit, 1/8″ drill bit
Socket or wrench set (need 1/2″)
Crescent wrench
Circular Saw w/ carbide or better blade OR jigsaw with metal cutting blade OR hacksaw

  1. Cut two 3.5-4″ sections of aluminum. You can see here that my cuts are not square. I have since had better luck with a circular saw, though a proper miter or table saw would be even better.

  2. Using the U-Bolt as a guide, mark and then center punch hole locations. Drill with 1/8″ and then expand to 3/8″.

  3. One of the two aluminum brackets needs to have an additional hole drilled in the center for our angle bracket attachment.

  4. Gather your hardware from the antenna kit (all of this should be included in the Amazon package I linked above).

  5. Assemble as pictured below, using the provided blue loctite on all threads. Note: per Wilson, the spring should not be used if you will be utilizing all 3 of the fiberglass extension rods. The crescent wrench comes in handy here.

  6. Install the U-Bolt and first aluminum plate at your preferred height. I chose to have the top of the antenna just higher than my solar panels.

  7. Install the angle bracket and antenna mount onto the second piece of flat aluminum. The black rubber washer here was omitted before installation, but should you have issues with movement, it’d be better placed between the aluminum and the angle bracket. Hardware order is bolt, fender washer, aluminum bar, rubber washer (optional), angle bracket, fender washer, nylock nut. Tighten.

  8. Put antenna assembly onto the threads of the U-Bolt, secure with blue loctite and acorn nuts. Tighten.

  9. Verify satisfaction with articulation. The antenna, when pulled backward, should rotate until the angle bracket hits the acorn nut. Should be firm enough to remain in whatever position you choose.

  10. Route antenna cable, making sure to leave enough slack for the potential articulation of the antenna mount. I ran it down the Aluminess tube, made a service loop, then entered the van near the hinge, then underneath the tail light black plastic housing, and up through an existing hole. Verify door movement and zip tie placement to avoid any nasty surprises.