This Is How I Did It! Tow Hitch Mast Support For Ham Radio Beam Antennas

I don’t even pretend not to be open to suggestions. So when one of my buddies mentioned that we needed a 6M beam to work digital modes on Field Day…well I realized I DID NOT HAVE A 6M BEAM! And of course, instantly I wanted one. And it had to be portable, and now all of a sudden I wanted to be able to work the greater than 50MHz frequencies, my van was being scoped out as a rover, and I was looking for the best way to attach a mast to it…And oh yeah, I needed a mast.

Googling masts made me realize I did not have a lot of options that would be good contenders for my brand of portable radio operations. I wanted something fairly sturdy, easily moveable and storable, relatively lightweight, simple and practical in design, and not extremely expensive. It would need to hold a couple of beam antennas, including new 2M and 6M antennas from Arrow Antenna. I stumbled across options from MFJ, Rohn, and even generic offerings on Amazon. I looked at flagpoles and wifi/tv masts. Finally, I decided upon a Max Gain Systems, Inc. MK-4-EXT model push-up fiberglass mast. As always, remember I have zero commercial interests, affiliations, etc. These are my purchases and I am just talking about them.

The MGS MK-4-EXT is composed of eight nearly 4 foot lengths of fiberglass tubing, of diminishing diameters from 2 1/2″ to 3/4″. The tubes nest into one another. It will extend about 28 feet and collapse to around 5 feet. The kit comes with seven connectors that need to be glued on one end of each but the smallest tube. These connectors essentially function as diameter reducers with a locking mechanism and require a large flathead or phillips screwdriver to tighten.

The fiberglass tubing arrives with a fair amount of fiberglass dust on them, so wiping them down with a towel can be useful.

The ends of the tubes opposite to where the connector will be placed need to be marked with a circumferential line at 5 1/2″ for this particular model. This length changes depending on which mast you purchase. I am finding that in practical use that I still miss the line when pushing up the mast, so I will be putting another circumferential “warning” line around the tubing. Originally, I thought I needs a board and a mallet to properly seat the caps on the mast sections, but the caps were quite loose and went on without effort. I would prefer it if they had seated more snugly. I used the board and mallet to help me mark the 5 1/2″ line on the tubing instead.

MGS recommends a few different glue possibilities for affixing the caps to the tubing sections. Their strongest recommendation goes to silicone sealant, aka aquarium glue. I used the Loctite big-box-store available product pictured, but there are several options. MGS also recommends not painting the edges of the tubing with glue and then pushing the cap over it. They say this will create too tight of a bond, and if the connector needs replacement, the end of the mast will need to be cut off. Instead, I think (I actually could not understand their wording and there were no pictures in the otherwise good documentation), they endorsed just putting a ring of glue around the base of the cap. At least this is what I did. One of my connectors did not get a proper seal this way and did come unglued. I will fix that and the rest seem fine. Loctite recommends 48 hours for proper curing of the sealant.

The connectors function in a manner similar to quick connects on bicycle seat posts. The lever provides a bit of additional tension to an already relatively secure tubing.

A screwdriver is needed while raising and lowering in my opinion, as trying to preset the tension before deploying did not work very well.

So without too much trouble the MGS mast was ready to be deployed. The next step would be to find a way to attach the mast to my cargo van (affectionately dubbed “Limey” for those of you not in the know) in a non-permanent manner. I decided I needed to install a tow hitch receiver. I set up an appointment to bring Limey in to U-Haul for the installation. This was a bit of a process due to their strange communication system and some supply chain shortages for my 2″ heavy-duty tow hitch receiver, but eventually the process was flawless. Now, I just needed to obtain the proper mounts. A little bit of research led me to a product called a pintle hitch mount. My first choice was the Curt 48349 adjustable pintle mount, however it was lost in the mail. How you lose a 26 point hunk of metal, I don’t know, but I tracked it across the country until delivery day–and then it was gone!

On a whim, I saw that U-Haul had a branded pintle hook receiver mount available in their store. It was several inches shorter than the 48349, but I thought it would work well enough. And I noticed that they had a receiver extension bar that I thought would be useful for being able to open Limey’s rear cargo doors with the mast attached.

My vision was to use u-bolts to create a sleeve for the mast. In fact, I had already ordered u-bolts specifically for the CURT pintle mount from McMaster-Carr product #8896T75 with a center-to-center bolt distance of 3 5/16″ to match the spacing of the horizontal holes of the pintle mount plate (see “F” in the u-haul diagram for what I mean). This company sent me these in record time! I was a bit disappointed to think that they may not fit my U-Haul pintle mount, but I planned on ordering more if I needed too.

The 2″ hitch extension and the pintle mount were assembled onto the back of Limey and a board was placed to provide a soft base for the end of the mast.

It turns out that my u-bolts fit the U-Haul mount perfectly! I just needed to obtain some washers, as the pintle mount design would not allow the mounting plate to cross over the back of it. If you look carefully at the picture below, you can see the u-bolt mounting plate on the front of the plate, essentially quite useless. It is washers on the backside of the pintle plate that are keeping the nuts in place.

Here you can see what I mean… Also, just as another fun fact, those buckets are filled with concrete and have a PVC pipe cemented into them. I use those as mast holders for my Mr. Longarms Painter Poles. They are always in my van and come in handy as weights!

One other bit of advice… if you tighten the u-bolts too much you will deform the mast a bit. This squishing means you will not be able to move the inner piece up or down. There is a bit of play in the whole system, so I used the concrete buckets to stabilize the mast.

Voila! Limey is now a rover! I have yet to get the 6M 3-element beam up, but the 2M beam went up flawlessly. I tried to catch a few minutes of the tail end of the ARRL June VHF contest, but no luck making any contacts. To be honest, I was much more interested in getting my mast set up than getting on the air!

I am really excited about using this for Field Day this year. The plan will be to use this as the “free” UHF/VHF station along with my Yaesu FT-857D. I may even put my diamond fiberglass 2M/70cm mast on top, along with the 6M and 2M yagis. The goal is to run FT-8 on 6M, with some other phone contacts in between. I have honestly never been more excited about non-HF bands! Hope to catch you on the air!

Always,

KM1NDY