The new antenna for 2010 at this QTH will be the popular G3TXQ Broadbeam Hex Beam. What follows is a look at the DX Engineering Hex Hub.
My new hex beam antenna will be a custom version of this configuration omitting the 17 and 12 meter bands and maybe adding 6 meters. This is all about contesting and I wanted a simpler version of the hex beam. K4KIO, Traffie, DX Engineering and others offer components and complete kits for the various styles of the hex beam.
If my plans included the 17 and 12 meter bands I would have purchased one of these kits with no questions asked. However, I felt my need for only 20, 15 and 10 meters (6m maybe) were not sufficiently addressed by the kits. Yes, you can get wiring just for these bands, but the cost differential was slight.
So I decided to custom pick parts for my own custom variation of the hex beam. The hub for the six fiberglass poles was a logical place to begin.
The hex beam has been around long enough to have a cottage industry to support it. Ever since the March 2009 QST article more manufacturers have emerged. The base plate suggested in Leo’s QST article and offered by most of the manufacturers use two U Bolts to hold each fiberglass pole. The HexKit.com baseplate is one example…
The instantly obvious issue is the way these flat plate units hold the round fiberglass pole. The U-Shape of the bolt is good, but squeezing the round pole to the flat plate can easily stress the pole. This is easily circumvented with saddle clamps and other methods that have been around for centuries, but I guess the stress on these poles is sufficiently low to not be a problem. I did notice many hex beam sites reinforcing the poles in the hub area while others have welded metal pipes instead of clamps. Perhaps there is a problem with fiberglass poles against flat plates after all.
Last year when I started thinking about making a hex beam, I seriously considered purchasing just the aluminum plate and purchasing saddle clamps of the correct size from DX Engineering like this example…
The mechanical benefit over U-Bolts is obvious. That said, hundreds of amateurs have been carefully using the flat plates with perfect success so it appears the more proper saddle clamp approach is only marginally necessary. However, I like doing things the more traditional way and swore I would use saddle clamps when it came time to build my own hex beam.
Time passed and other distractions caused me to shelve the project for a bit.
Then lo and behold… DX Engineering decided to enter the hex beam fray. Everything about their hex beam offering seemed pretty much run of the mill with the sole exception being their hub and especially the way they connect the poles to the hub. Here is a close view of the pole attachment point…
Wow. This offers the benefit of a saddle clamp, but with the saddle running the whole length of the pole-hub interface. Brilliant.
The hub costs about the same as the offerings from other vendors so there was no real financial advantage of any particular model. The sole exception is folks who make their own plate from raw materials and trade their time for cash savings; Kudos to them. My time is worth a bit more than the hundred or so dollars hex beam hubs cost.
Needless to say specifying the DX Engineering hex beam hub in my design was a no brainer and that’s exactly what I did earlier this week. The web site said they were out of stock, but it arrived in a few days during a snowy mid-atlantic Saturday anyway.
I have purchased DX Engineering products before with the primary feature being excellent documentation. I decided to see if my Lego building seven year old could put this product together. Let’s see what happens…
The seven year old had no problems at all except for that V-Bolt moment.
So the DX Engineering Hex Beam hub is here and the project is officially underway. I patiently await the arrival of wire and rope from The Wireman and fiberglass poles from MaxGain Systems. Hopefully by March I will have my 20-15-10-6 meter contest band hex beam ready to go for the Virginia QSO Party.