Mobile Repeater Trailer


Why Build ?

For many years I used a simple portable radio tower that used the weight of my truck parked on a stand to hold it up. It was only a 40ft tower, and all the electronics had to live in the truck to stay out of the weather. This got old after about 10 years, because as I had to setup on the best tower location, my truck and it's other supplies were often far away.
Montana, 2000

When I did Katrina Relief work, I got inspired looking at some of the large mobile towers brought in by the goverment emergency services. I decided it was possible to build one that would be much cheaper than the major $$$ the commercial ones cost.

This then got stalled for a while, as it was hard to determine the best trailer. For my purposes, it needed to be narrow so it would fit on a dirt 4x4 road, and robust enough to survive the often difficult off-road driving to get to the best tower locations.

Then one day in the local rural paper, I saw an ad for what turned out to be the perfect trailer, and it was only $300! Better yet, it was only a few miles away, so after checking it out, I bought it. The owner threw in two old tool boxes as well, mostly to get rid of them. Here's the trailer before any modifications were made:

Building the Trailer

Once I had the trailer I then had the problem of adding bracing where I needed it. Luckily there was a local welding shop, so I towed the trailer there. We basically designed it on the spot, based on what worked the way I needed it to, along with the metal scraps he already had in his shop.

As the original trailer was built in the 50s for hauling propane tanks, it already had a nice sturdy A frame in the middle. As the trailer frame was a big U shaped thing, we added a top bar as a big hinge for the tower. The tower itself is a 60ft telescoping one made of steel, which shrinks down to 12ft.

As the back of the trailer was open, the tower can rotate 90 degrees. Directly below the top bar, we added a steel brace between the two sides of the frame. When erected, the bottom of the tower clamps into place on this brace to it can't rotate while erecting it.

The two outrigger just below the top bar are for a platform to stand on when erecting the tower. This way all the fittings and antenna connections are easily accessible.

Travel Mode

I often have to drive this trailer thousands of miles every summer, so how well it travels is important. In addition to the tower itself, I also haul my Stokes backpackable basket litter, and a backboard. These fit better on the trailer than in my truck.

The front supports of the trailer were designed to hold the Stoke litter, plus it add a nice weight to the front to make towing better. With the Litter off the trailer, it's then light enough in the front to pick it up for moving the trailer around by hand.

The backboard nicely fits on the equipment box, strapped to the opposite side from the Photovoltaic panel. When Traveling, I can drop the backboard down, which covers the gap between the two equipment boxes, and by throwing a tarp over the tower, it's an instant tent. Nice for longer trips that take more than one day to drive. The old Elk antlers were just for decoration.

In Use

It's been great in use. I've gone from needing 10 people to put the old portable tower up, often taking hours, to doing it by myself in under 30 minutes. Course with 1 or 2 people helping, it's even easier.

It's now seen heavy use all over the western United States.

Copyright © 2012 Seneca Software & Solar, Inc