The original idea of a portable ‘POTA’ hex beam came as desire to improve my antenna situation when activating POTA sites and portable contesting.
My go ‘go to’ antenna over the last year and a half has been an EFHW (Either 40 or 80m model), which works very well. But there is always room for improvement.
Several goals drove the design. It had to be setup quickly (30 minutes or less), is relatively inexpensive, and something I could build.
After considerable research I decided on the following design. I uses 6 carbon fiber crappie fishing poles, a home brew or manufactured hub, lightweight cord for the supports and other parts from the local hardware store.
The spreaders use a Goture, 15 foot fishing rod. I choose this size as I didn’t what know the finished antenna would eventually need. It is actually too long, I eventually ended up using the bottom 5 sections. I would recommend ordering 4 of one color (Brown), and two with of a different color (Green). The two green ones can be used for the driven elements, making it easier to see which direction the beam is pointing.
Rope selection. After some thought I decided 550 cord would be overkill, so I opted for some 1.18 mm cord. It has a 125 pound breaking point, and is very light. I opted for a darker color to help make the antenna more stealthy (didn’t work).
|Use||Length / Number|
|Spreader support||6 x 124.5 (+ 24″ for loop and knot)|
|Driven element support||1 x 115 (+ 24″ for loop and knot)|
|Center post||36″ 1″ PVC pipe|
|1″ PVC cap|
|5″ 1″ PVC||6 to hold end of fishing pole on|
|3/4 inch Stainless Steal 1/4 screws||2 per wire set|
|1/4 locking washers||4 per wire set|
|1/4 SS nuts||2 per wire set|
|1 1/4 PVC (for baseplate mounting). Adds additional padding between baseplate and center post||1|
|14 Gauge wire||Wire set dependent|
|1/4 SS Eye bolt, with washers (2) and nuts (2)||Top of center pole|
|1/4 Thumb Nuts (To connect wire-set to feed point)||2 per wire set|
|NiteIze #0.5 S Carabiner (Wire and support quick connect)||10|
|1/4 ring terminals (Coax, wireset, feed feedpoint)||8 per wire set|
|Black wire ties||12 per wire set|
|Duct tape||At least 3 foot.|
|1″ hose clamp (To mount on the mast)||At least 1|
|24″ RG8X coax with PL259 on one end||1|
|Yo-Yo hand reel (To store the 20m wire-set and support cords)||1|
Cut the support cords to length. This took some trial and error. But ended up with 6 x 124.5″(between the loop ends) lines to support the poles, and one 115 (between loop ends) to support the gap between the driven element spreaders.
Now on to the wire sets. I started with the lengths from hex-beam.com ‘s chart for 20M, adding an inch to each driven element and two inches to the reflector. Some additional tuning finally brought the antenna up to where I wanted it.
Loops were tied on to the wiresets about 124″ inches apart, allowing a quick connection to the support cord. I’d recommend a temporary loop, then adjust the location of the stays.
The center post was constructed using the instructions from the hex-beam page, with a couple of changes. The first being the 20m mounting screw holes where drilled in 3″ from the top. My second build also allows me to add other bands as needed (Hence the extra pole length).
Drill a hole in the end cap, and attach the eye bolt with one nut and one washer inside and outside. Then slide two S-Caribiners inside the eye bolt and hammer shut (They will slide out if you don’t).
Using a 1″ piece of 3/8 clear tubing at the end of pole, I tied on an 18″ piece of cord. This allows for several loops to adjust the tension of the lines. WARNING: Do not use wire ties to connect the rope. The tubing is very thin and will collapse with enough pressure.
Now on to the spreader support cords. Using the 6 124.5″ cords, connect one loop to the center post, and the other end to the free end of the spreader using an Carabiner.
Finally take the 115″ cord, and connect it between the driven element spreaders.
Lay the wire out before trying to connect it to the antenna. Trying to unwind it from the spool as you connect each stay will eventually end up as a hair ball (Trust me).
Connecting the wire set is actually pretty easy. Connect one end to the center pole, then connect the wire to the end of the spreaders using the existing S-Caribiner.
Finnish by connecting the other end to the remaining feed point.
Tearing down (Important)
Tearing down and storing the wire and cords in the proper order affects how quickly you can set it back up.
- Disconnect the wire set, and lay it out on the ground. This allows a free end to allow the twists to ‘spin’ off the end as you coil. Using the Yo-Yo reel, wind about 10 turns on, then flip if over and wind the opposite way. This helps untwist the wire as you reel it in.
- Disconnect the spreader support lines from the center pole.
- Starting with the end of one of the spreader arms (The one with an Carabiner), clip the carabineer into the wire set ring terminal. Wind the support cord on. Clip the next support cord into the loop (Repeating 6 times) until all of the long support cords are stored.
- The last cord that should be store is the driven element. You may want to clip and extra Carabiner in the loop (for quicker setup)
- Remove and store each fishing rod
- Extend each fishing rod and place it the center plate PVC pipes.
- Connect the driven element support (This is between the two driven element spreaders)
- Connect each spreader support cord, starting at the middle. The Carabiner connects to the end of the spreader furthest away from the center pole.
- Run the wire set out on the lawn.
- Connect the wire set to one of the feed point screws.
- As you walk around the antenna, connect the antenna stays to the end of the spreaders (using the previously attached Carabineer).
- Connect the other end of the wire set to the remaining (open) feed point screw.
Mount and POTA
I use a Max Gain 25′ pole to get this up in the air. I picked this one as I felt the shorter sections would make it easier to reach the end. Well yes and no. The whole collapsed mast is almost 6′ long, making a bit tough to slide the antenna over the end. I finally opted to get a small folding ladder to make it a big simpler.