The Mast

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CIMG3851c_Medium_-340x288One of the biggest advantages of a hexagonal beam over a conventional multi-element HF beam is that you can get by with a very economical support structure with the hex. In fact, you can buy a hexagonal beam and the materials for a decent support structure, all for a fraction of the cost of a typical tower needed for a SteppIR or a Force 12 beam. This is why the hexagonal beam has become so wildly popular. You can actually have a directional antenna that works well and not have to spend your retirement to get it.

The typical support structure for a hexagonal beam is a push up mast, a roof mast, a chimney mast or numerous other creative arrangements. You can see a wide variety of these here and with a little thought, come up with a support structure that fits your situation. Despite neighborhood covenants and restrictions, you can frequently find a way to erect a hexagonal beam that is discrete and doable without hiring a professional tower crew.

With the 4X4 post in concrete, a ladder can be leaned against it to enable one to push the mast up with the hex beam on it.

Step7rotator-600x399We feature here, the push up mast arrangement of the author. Are we bragging? No, in fact the reason for featuring this arrangement is to show that a primitive, obviously home-brew structure can actually work. It is one that you can build.

My mast is a 30 foot Channel Master push up telescoping mast that cost about $90. I sank a twelve foot 4X4 treated post in concrete to serve as a rigid support and mounted the push up mast to the post. With the post sunk in concrete, you can lean a ladder against it to get up high enough to push the mast to its maximal position.  You can climb the ladder with the hex beam and then mount the hexagonal beam into place on the mast before extending the mast sections. Some neighborly help would be nice for this although I was able to do mine completely alone.

The guys are every ten vertical feet and Dacron rope is fine for this. It is a good idea to completely extend the mast without the beam and then adjust all the guy ropes. After this, lower the mast and install the beam on the top as shown.

Shown in the photos are the rotator mounted at the bottom on a home-brew bracket made from angle stock from Lowes. At the top of the post is another bracket for mounting a thrust bearing. A thrust bearing is a device that supports all the weight of the mast and beam and allows the mast to rotate freely so the work and weight on the rotator is minimal. These brackets are easy to make. All you need is a hack saw and a hand drill to fashion them for your situation. Or you can buy shelf brackets that will do the job too. Check out these brackets.

Step7bearing-600x399Coupling_AAlso shown is the bottom of the hexagonal beam as it rests on the mast. Note that the bottom flange has a cross bolt in it. This cross bolt is essential as the set screws in the flange are not adequate to resist the constant torque and moment of the rotating beam. In a short while, the beam will be free wheeling if not for the cross bolt. The push up mast is a pretty good fit for the bottom flange but some shimming with a thin piece of sheet metal might be a good idea to eliminate any wobble.

You can download a copy of our Push_up_mast_guidelines here.