Hex Beam by K4KIO
Site publication date
12/2007
Click these photos to enlarge
Step Six - Installing the wire elements

  • Begin with the 20 Meter band first and install all four wires with the two tip spacers using the steps below the photos.  You will probably
    need to adjust clamps and the cords to get the wires in the right position with each other. Try to be precise as your success here will
    establish the shape and integrity of the hex shape for all the other wires.

  • After installation of the 20 meter wires, you can remove the temporary nylon perimeter and radial cords. You should have a total of six
    permanent kevlar/dacron cords installed; four radial cords on the back four spreaders and two perimeter cords on the front two
    spreaders with one of these two about half way toward the center post.

  • When you are satisfied with the 20 meter wires, this same process should be followed for the other bands. But here is an important
    point. The 20 meter wires and the six cords will provide the necessary tension to maintain the shape of the hex beam. Therefore, the 20
    meter wires will be much more taut than the other bands. However, it is neither necessary nor advisable to tighten the other bands to
    the same tension as the 20 meter wires. In fact, it is much better to allow the other bands' wires to be relatively slack. Over tightening
    them can distort the shape of the hex beam.

  • When all the wires are installed, adjust clamp locations for all the bands except 20 to make the wires parallel as much as possible and
    level with the ground. This is a little more art than science but your goal should be to seek overall symmetry among the wires and a
    horizontal plane. Because the entire structure is flexible, you will find a good bit of interaction among the wires as you take up slack and
    move clamps around. Some patience is needed to achieve the overall result.
Install connector blocks to the
clamps 6 inches from the ends
of all six spreader.
Connect the driver wires to the
terminal posts. Then string the
driver wires through the
connector blocks on Spreaders 1
and 6. String the reflector wire
through Spreaders 2,3,4 and 5.
Connect the 20 meter tip spacers
so as to make a loop all around
the perimeter of the hex beam.
Adjust the tip spaces for 24
inches for 20 meters and tighten
the set screws.
Measure 128 inches* along the
driver wires from center post to
the connector blocks. Pull the
wires taut and tighten the set
screws. Notice here that I added
some copper wire support
because of the amount of
tension at this point.
Install a perimeter cord
between the two front
spreaders to hold them from
pulling out of position. Adjust
this cord for 128 inches. Then
install four radial cords from
the center post to spreaders
2,3,4 and 5 and adjust each of
them for 128 inches. One of
the radial cords to spreader 2 is
shown here.
Stand back and look across the
hex beam. You can shake it a
bit to allow the 20 meter wires
to run loosely though the
connectors on spreaders 2,3,4
and 5. When you are satisfied
that the spreaders are not bent
laterally and the wires are
generally of equal tautness,
you can tighten all the
connector set screws.
  1. Install cable ties at the clamps on all spreaders at 100, 83, 70 and
    61inches for the bands 17 –  10.
  2. Connect the driver wires to the center post terminals
  3. String the driver and reflector wires through the cable ties.
  4. Install and adjust the Tip Space assemblies to the specifications.
  5. Adjust the clamp locations on the spreaders to make all wires equally
    taut.
  6. However, the wires for all bands except 20 meters should not be tight;
    they are not used for establishing the shape of the spreaders. A little
    slack will not diminish performance.
  7. Do not use the connector blocks for these bands; they are not
    necessary and they de-tune the wires. Actually, they de-tune the 20
    meter wires a little but this has been factored into the design and is
    not significant for 20.
Building the G3TXQ Broad Band Hex Beam
* Why 128 inches?

It's geometry. Look at this:

You have two driver halves @ 218 = 436
You have one reflector @ 412
You have two tip spacers @ 24 = 48

Add it all up and you get 896 inches. Look at the sketch of
the broad band hex beam and you'll see this all makes up
a big loop with seven equal sections.

Divide 896 by 7 and you get...

128 inches. It worked out pretty precisely for me and by
using that guide, the beam is pretty much on target. (Yeah
I know, you have the center post, bends in the wires, etc.
But, still you can use 128 and you'll be "close enough for
government work", as my Dad used to say.)