History Baseplate hexbeam site hexbeam site Wires & cords
Building SWR & tuning Do's & Don'ts Installation References

 

Building

Once all parts are ready you can start assembling the hexbeam. Put a pole in the ground where you have some room to
assemble the beam. If you can't finish the project in one day, make sure it's on a safe place for kids, woman and mothers in law.
Before insirting the spreaders into the baseplate, I added rubber boots to prevent cracking the fishpole while tensioning the U-bolts.
I used fuel-flex, costs about 5eur/m. It was a little to small so I had to cut the boot in half.
Insert all fishpoles and put some tension on the U-bolts. Now come the support cables in place, start with the six supportcables
between the end of the spreader and the centerpost. Slip the S-hook over the screw at the end of the spreader and attach the
other side on the centerpost. Don't work clockwise, always take the opposite spreader to prevent bending the centerpost.
When the six main supports are installed, you can start installing the 6 additional support cabels between the top of each spreader.
Here I worked clockwise.
 

 

rubber boots

Spreader 1, see cartonboard with support cords

Hex-shape

Ready for the sky

When all the support cords are installed,and all cords have the same tension, you should have a very symmetrical construction.
Time to install the drivers & reflectors. Start with the 20M band. So far everything went smoothly, but at this point I found my
first issue. Seems there's a bit to much bow and I had to move the hose clamps up to the edge of the fishpole.
Lucky me I cutted the the fishpoles @ 355cm and not 353, the minimum length. There's still a bit slack on the wires, but that
shouldn't affect performance. When 20M is fine you can start installing the other bands.
If you have to move the hose clamps make sure you move them all for that particular band.
To protect the fishpoles from cracking while tensioning the hose clamps I wounded some tape on the fishpole on these particular
places. I advice you to wait with the tape when assembeling the fishpoles, because you propably have to move the clamps a couple
of cms. To support the wires I used plastic straps. Use the black ones, there UV resistant, I advice a minimum width of  5mm.

Attaching drivers to centerpost

tape, hose clamp & plastic straps

Keep the 10m driver as tight as possible to the FP

Tip space twice through connector (I'm a lazy photoshopper)

Teammember ON4ATA adviced me to solder all cupper joints from the coax-pieces attached to the centerpost.
This had 2 advantages. It prevents the coax sucking weather when raining and it allows the silicons to stick better on the surface.
In the DIY shop they told me cupper rejects all kinds of silicons.
Other pictures show how the drivers & reflectors are attached to the fishpoles. The last picture shows how I connected the tip
space to the driver. I propose to put the wire twice through the electrical connector for more secure connection.

 

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SWR & Tuning

When all drivers & reflectores are installed it's time to connect the transceiver or SWR analyzer. Lucky me, our clubstation has
the popular MFJ259, thanks ON4EKO. The antenna got raised on an old boom and the first test was done @ 4m.
The results were fair, but with a little tweaking I should be able to improve the SWR results.
On 10 & 20m the dip was to low, so I had to cut the drivers a couple of cms. To calculate the new length and the difference you
can you use this formula : New wirelength = old wirlength X (old frequency / new frequency)

For example:  553,7 (driver 20m) X (13.800/14.100) = 542, so I had to cut the 20M driver 12cm.
 

SWR results for the HEXBEAM @ 4M and after tweaking at final heigth @ 12M

 20m - 14Mhz

Remarks

  • Initial dip was @13.8, so I cutted 12 cm and found great SWR curve at final height.
  • Good front-to-back
  • Didn't changed the length of the reflector, not for this band, not for any other.

17m - 18Mhz

Remarks

  • SWR seemed OK @ 4m. Once on the tower best SWR is at 17.5Mhz. When the antenna has to come down for maintanance I'll tackle this issue.

15m - 21Mhz

Remarks

  • SWR seemed relatively OK on test height. , only removed 2cm of wire and got good results. Antenne seems to get more broadbanded when rising.
  • When maintaining the antenna I will try to shift the dip a few 100Khz.

12m - 24Mhz

Remarks

  • nothing to add here. Had to remove 6cm from the initial length and got flat SWR accross the band.
  • Initial dip was 1.1 @ 24.4Mhz

 

10M - 28Mhz

Remarks

  • First I taught it was tricky to remove 8cm from each driver but result is a great SWR curve.
  • SWR doesn't reach 2.0 before 29.6Mhz
  • Initial dip was 1.2 @ 27.3

     

     

Does it work?

Well, the last few days in a limited timeframe I managed to work K5D on 17 & 20M both SSB & CW, 9Q, 9K, J7, K4A, ...
The answer is definitely YES

 

 

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Do's & Don'ts

Make sure the screw on top of the centerpost is long enough to support the 6 S-hooks
Don't cut the fishpoles at the minimum length, foresee some extra cms.
When attaching the wire to the cable shoe, make sure you solder it close to the end of the cable shoe.
For maintenance reasons I advice you to cut the 50ohm calbe just above the RF-choke. This allows to thake the antenna down
and leaving the coax at the tower.


I'll complete this list when things come to mind.

 

 

 

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Installation

 

It's light but remember it's size

Don't try this at home.

Tilting the hexbeam

Securing the hexbeam

Ready to werk DX

The black spot  under the hex is the RF choke

 

 

References

G3TXQ - the inventor, K4KIO - The reference for builders, DL7IO - some good design tips
PG3N - good ideas and PA2JJB some good ideas as well.

 

Special thanks to Patrick, ON4CLQ for the baseplate and the welding of the flence, ON4EKO for the use of the SWR
analyzer,  my father in law Rudy for his tips & tricks with the mechanical construction and help with testing and installation
of the antenna. Last but not least my girlfriend Kelly who's supporting me and this wonderful hobby.