HOMEBREW HEXBEAM PAGE
by W1GQL

 

 

 

 

 

 

 

Homemade Hexbeam Users

This page is still ready to grow!! I hope to have a lot of links here to information from other Hexbeam Users and lots of pictures. Please get in touch with me if you would like to see your Hex featured here. At this point we want to focus our attention here on innovations and new or clever ideas for building a homebrew Hexbeam.


Caleb Wright WA2JJX

 

      Caleb Wright, WA2JJX, has built two Hexbeams. He has done some clever work. Both of his Hexes have been built using my dimensions. They both have had low SWR right from the start, but eventually he did shorted the elements of his second Hex by about 2 inches. He did this by simply twisting the wires at the apex, or V, together about 1/2 inch. This slid the SWR curve up a little, placing the 2:1 point near the low end of 20. The SWR drops rapidly from that point and stays quite low accross the band as the model predicts.

     His first Hex was made using bamboo poles. He was only able to find 8 foot poles and had to extend them with wooden dowels. He tied two dowels together side by side and bound them to the end of the 8 foot bamboo. He then fiberglassed the entire poles. His hub was also made of fiberglass. He even fiberglasses a wooden rod {going through a hole in the middle of the hub} right to the hub and did away with the need for any metal fixture at that point. I liked that idea a lot. A good innovation.

      Caleb used my method of feeding both Hexes, namely using a 2" by 3" piece of plexiglass and offsetting the feed point a bit. He also used my suggestion of feeding a 17 meter Hex element with its own separate coax feedline. When you feed them with one feedline the wires lengths have to be different than they are for a one band Hex, and if something happens to one bands wire, the whole antenna is thrown off. This is one of the advantages of using separate feed.

     Caleb dubbed this first Hex "Martha II" after he heard about the bamboo Hex of Joe N9PH made with bamboo from K-Mart where Martha Stewart sells. Unfortunately Martha II ran into hard times just like her namesake. One of her poles snapped, not in the wind but while the Hex was being taken down for adjustment. (Happened to one of mine as well. Hexbeams seem to suffer more on the ground than they do in the air. Hi).

      Caleb built his second Hex using 6 Crappie poles his wife won on an Ebay bid from HarLee Rods. They cost him a bit over $20. They were telescoping and made to extend to 13 feet. He left the last telescoping section off.

      I liked the way Caleb attached the mast to this "Crappie Martha" (as he calls it). He used 3 small right angle shelf-type brackets and then used an adjustable stainless steel pipe clamp. I liked the idea very much and incorporated it in my third Hex.

      A innovation that Caleb used on both of his Hexbeams ( and one that I used at his suggestion on my third portable Hex) was to attach the spreaders to the hub using cable ties. He is an engineer and he calulated the stresses involved and decided to go with the cable ties. It certainly makes the antenna lighter than it would be with metal U-bolts.

      Caleb's greatest contribution to the science of "Hexology" is his innovative mast/tower. It tilts with the help of a small hand winch he also bought on Ebay. The entire mast turns and the rotor is mounted at the bottom. (This is a great idea. My hex would tilt up easily until I put the small TV rotor right under it.) Originally Caleb used 2 inch ID PVC drain pipe for a mast. Although it worked, when he tried to get the height up to 20 feet the PVC bent badly. Eventually Caleb bought a 20 foot length of 2" aluminum pipe. He was fortunate to find it at a metal suppier near his office and got it home on his own. Shipping it by common carrier would have been prohibitive. I hope other hams will come up with some other mast possibilites that will be easily obtainable. (My third portable Hex is on a 20 foot mast made up of two eight foot sections of 2 inch aluminum I resqued from the mast of a dead 20 M full size yagi. I have a couple four foot sections of 2" ID diameter PVC drain pipe for couplers and short extensions. Luckily they telescope perfectly.)

      If you would like to contact Caleb Wright you can email him at caleb(at)taconic.net. (replace the "(at)" with @)



Harvey Mandell WA2AAE

 


     Harvey did a beautiful job making at 20, 17, 15 multi-band hexbeam fed with one coax. I'll let Harvey tell about building his hex:

 What interested me about the Hex Beam was the ability to cover the WARC bands
 and what appeared to be the simplicity to build. I had been using a Hygain TH-2
 previously, but when I had a new roof put on my house a couple of years ago 
 this antenna and the roof tower had to come down. Using only my inverted V 
 antenna left something to be desired when there were pileups. 

 I initially built the five band, top fed, version of the Hex beam. I had problems 
 getting the SWR down on some of the bands so I put the antenna a side for a while. 
 Recently I noticed that Holger, DL7IO, had a presentation that showed a tree
 band version (20,17,15) that was bottom fed. This is the final configuration 
 of my Hex.

 I first tried Crappy Poles as the spreaders but found they were not very rugged
 and one of them broke early on in the project. Searching the Web, I found a 
 company called MaxGain Systems that offered fiberglass rods and tubes in the
 sizes I needed.  I purchased six eight foot lengths of 0.75 inch tubing and 
 six eight foot lengths of 0.5 inch rod.  The rod slipped easily into the tubing,
 allowing me to obtain the 10 foot length needed for each hex arm. I slit the 
 far end of the tube and used a hose clamp to hold the rod in place. 

 To hold the element wire I initially used some plastic tubing from a toilet
 water feed tube which is about 0.375 inches in diameter. I drilled a hole 
 through the tube for the wire and held the tube in place with a hose clamp.
 I later replaced this tubing with some black nylon rod that I thought would 
 allow the wire to slip easier.

 For the spreader mounting plate a purchased a 12X12 inch, 0.25 inch thick,
 aluminum plate. This plate, as well as much of the stainless hardware, was 
 purchased from McMaster-Carr’s web site. This is a wonderful source of material 
 for experimenters since their prices and shipping cost are very reasonable. 
 Their selection of material is very large so they probably have whatever you 
 need.  I drilled the mounting plate to have two U-bolts for each spreader at 
 a 60 degree spacing.

 To reinforce the spreader mounting I used some PVC pipe to go over the 0.75 
 fiber glass tubes at the mounting points. Since I had bought the U-bolts to 
 fit the Crappy fishing rods which had a greater end diameter than the 
 fiberglass tubing, I had to add another level of PVC tubing to make sure the 
 U-bolts grabbed the rods tightly. This would not be needed if the U-bolts are
 the right size for the rod. 

 The rest of the construction is pretty much similar to what others have done;
 a piece of 1.5 inch PVC pipe in the center to support the elements and 
 transmission line between elements, I made the bracket to hold this PVC support
 and the bracket for the mast from some 0.25 aluminum “L” material.

 Initially I had some SWR issues with the three band version, on 15M, which 
 I was top feeding in error. When I switched to bottom feed these problems 
 went away. During this troubleshooting period it was suggested that my 14 AWG 
 transmission line between elements might not be big enough and causing the 
 SWR problem. I replaced the wire with the braid from RG-8 coax that I 
 insulated with shrink tubing. This did seem to help.

 I have not had a chance to mount the Hex Beam in its final location yet. It
 is presently sitting on a mast about 15 feet above the ground and I have
 made several contacts in Europe. I plan to either build a tilting mast 
 support, like others have done, or mount it on my roof. The antenna in its 
 present location is shown in this photo.

 
(I have checked the MaxGain site and note that if you want to ship 8 ft sections by UPS they automatically charge for a 70 pound shipment and add an additional 7 dollars. That might be a problem for some homebrewers. I think you can order shorter sections of three sizes that would telescope and get by with cheaper shipping. Dave)
You can email Harvey at wa2aae(at)yahoo.com. (Replace the (at) with @)

Gerry K2HIG

 


     Gerry incorporated ideas from this website in the construction of his antenna. He had tried used fiberglass poles but for some reason they seemed flimsy to him. He finally used 3/4 in PVC. His hub is an old cable reel end, 24 inches in diameter, and is heavier than he would like. He used stripped down @10 Romex for his elements. He used nylon cords around the perimeter for structural integrity. He estimates that the antenna weighs about 10 pounds. He calculates his wind load at about 2.5 feet and says he is not really comfortable with the Radio Shack variety of rotor. (I think that if he made a lighter hub, he probably would feel better about this.) See Gerry's note on a recent Field Day operation using his Hex. It's great. The note is in the "On Air Results" section of this website.

	
	
	
	
	
	
	
	
	
	
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