2. Are the wire lengths critical?
A. Well, if you change the wire length for the reflector on 10M by one inch, it changes the design frequency by about 130 kHz. Two inches would be about 260 kHz, and so on. You can do a simple ratio of frequencies to figure the change in wire lengths for adjusting the tuning different from the table values on this web site.
Percent Increase in wire length = Percent Decrease in frequency
If you change the reflector lengths be sure and do the same for the driver wires. (e.g., increasing Reflector 3 inches requires increasing each half driver 1 1/2 inch.)
3. How important are the tip spacers?
A. They affect the front/back performance and the SWR and are designed for the optimal balance of these two performance criteria. But if you are off an inch it isn’t going to make a lot of difference.
4. What if I want to use a different gauge of wire than 14 or 16 gauge?
A. That is fine. To use 12 ga. wire, just multiply the table wire lengths by 1.004. To use 18 ga. wire, multiply the table wire lengths by 0.998. Leave the tip spacers as they are shown in the tables.
5. How high should the hex beam be?
A. Higher is better for DX generally as it reduces the takeoff angle of the main RF lobe. However, the hex beam can be quite effective even at modest heights. Some say 40 feet is optimal and that spending bucks on more height just isn’t worth it. That’s probably a pretty good rule of thumb.
6. What about use of steel wire or aluminum instead of copper?
A. Your main concern will be the physical properties as there is not much difference in the performance among different wire materials.
7. What about stranded wire or solid wire?
A. Either is fine. Solid wire is harder to work with, of course. Use the same wire length table for both.
8. What about insulated wire?
A. It can be used and if it is the specific wire in the table here you already have the specs. But you can’t depend on these specifications for all other insulated wire.
9. How important is spacing on the center post?
A. Post spacing can become a problem if the terminals are closer than 4 inches from each other. The RF current is highest right at the terminals so if they are too close together, RF interaction can be significant.
10. Should I feed the hex beam at the top or the bottom?
A. Top feeding will provide better results overall.
11. Should I connect the bands with wire or coax?
A. Coax will provide better results. Use 50 ohm coax.
12. Do I need a balun?
A. It is a good idea because it prevents surface currents flowing on the exterior of the coax and thereby distorting the radiation pattern.
13. Can I substitute materials if those on the parts list aren’t available?
A. Well, sure. Your substitutions might be better than mine. Just be sure you know the physical factors that are important and make judicious choices. There are only a few things truly critical about the details of a hex beam such as wire length, general shape, etc.
14. Where can I learn more about the hex beam theory?
A. Visit the web site of Steve, G3TXQ.
15. Can I buy a broad band hexagonal beam?
A. Thought you’d never ask. Seriously, we sell a multi-band hexagonal beam on another web site that is already built. You just assemble five modules when you get it and it works with no tuning. DX Engineering sells a kit of parts with illustrated instructions to build a broadband hexagonal beam. Is it as good as mine? Well, I’m sure it’s a good product but be prepared to do more work than you would do with one purchased from us. You get over 200 parts and a 38 page manual.