Understanding the Hexbeam

Understanding the Hexbeam

Hexbeam on a summer's afternoon

The Hexbeam is a great little antenna! It should be high on your list of options if you want a design that can be "multi-banded", exhibits useful gain and directivity, is very lightweight, has a small turning radius, and which lends itself readily to "Do It Yourself" construction.

Please note that the term "Hexbeam" is used on this site in the generic sense of a directional wire antenna that can be conveniently suspended on an hexagonal support structure. It does not refer to the Hex-Beam® manufactured by Traffie Technology of Ashby, MA USA.

I first got interested in the Hexbeam after seeing it described on various websites, but I was puzzled by conflicting sets of published dimensions and hearing that some constructors were disappointed by the Front-to-Back performance they were getting. That led me on a quest to try to understand the Hexbeam better. After hundreds of hours computer modelling, and many more hours building and testing prototypes, I think I understand it a little better. These web pages are a record of what I learned; I hope they will give you a detailed insight into how the antenna works, will encourage you to construct one for yourself, and will help you get the best out of it if you do.

In the Autumn of 2007, my computer modelling and practical experiments led to a new design of Hexbeam which, for a modest increase in size, provides a significant improvement in performance and SWR bandwidth over the traditional design. It was the subject of an article I wrote for the December 2007 edition of Antennex - the on-line magazine for antenna experimenters. To distinguish between the two designs on this website, the new antenna will be referred to as the "G3TXQ Broadband Hexbeam" and the traditional will be called the "Classic Hexbeam". There is a section devoted to each of the two designs, followed by material that is relevant to Hexbeams in general.

I am indebted to Leo (K4KIO) and Holger (DL7IO) for producing websites that first excited my interest in the Hexbeam. They have been very supportive in my efforts to get a better understanding of how the Hexbeam works - at the last count Leo and I had exchanged over 500 Emails!

Although these pages contain some photographs of my own Hexbeams, they do not provide detailed constructional information. If you need guidance on making one, you should visit Leo's website where you will find step-by-step instructions for building the Broadband Hexbeam or, if you wish, the older Classic design.

A number of commercial companies can supply parts or complete antennas, including:

If you want to keep up to date with what's going on in the Hexbeam world you should take a look at the Yahoo special interest group.

Although much of the discussion in these pages is based on my practical experiments, a lot is also the result of simulating the Hexbeam's performance using EZNEC+; I have therefore included two pages on modelling the Hexbeam which demonstrate that the results obtained through simulation are borne out in practice.

Unless otherwise stated, performance parameters are quoted for a Free Space environment and Gains are quoted referenced to an Isotropic radiator (dBi). This approach is convenient because it allows antennas to be evaluated on a "level playing field" without needing to consider the effect of the local environment (height above ground, ground conductivity, etc); it is also consistent with the way most commercial antenna manufacturers choose to quote their data. However the "real world" will modify the results that you get in practice. For example, I have found that on-air testing of F/B ratios with DX stations consistently produces figures that are around 10dB higher than predicted by Free Space modelling. This does not invalidate Free Space modelling - but it means you have to be careful how you interpret the results!

Finally, don't let the volume of data on these Hexbeam pages put you off having a go at constructing one - K4KIO's website has step-by-step instructions - I'm sure you will be pleased with the results.

I would welcome questions or comments on this material. Mail me at: hexbeam{at}karinya.net