Specifications and FAQ's
| Lengths of wire elements and spacing Note that driven element consists of two 1/2 sections and reflector consists of one section Units are Inches 1 inch = 2.54 cm |
Overall data on the
G3TXQ Broad Band Hexagonal beam by K4KIO
Freq. bands (M) 6, 10, 12,15,17,20
Weight 25 lbs
Diameter 22 ft
Wind Surface Area 5 Sq Ft
G3TXQ Broad Band Hexagonal beam by K4KIO
Freq. bands (M) 6, 10, 12,15,17,20
Weight 25 lbs
Diameter 22 ft
Wind Surface Area 5 Sq Ft
| Single Band G3TXQ Broad Band Hexagonal Beam (Top View) |
Hexagonal Beam by K4KIO
Building the G3TXQ Broad Band Hexagonal Beam
Other Sites
Understanding the
Hexbeam byG3TXQ
Yahoo hexbeam user
group
G3TXQ Broad Band Hex
Beam built by WY3A
Understanding the
Hexbeam byG3TXQ
Yahoo hexbeam user
group
G3TXQ Broad Band Hex
Beam built by WY3A
|
|
| For use with #14 or #16 Ga. PVC insulated copper wire only |
| For use with #14 or #16 Ga. bare copper wire |
| Site publication date 12/2007 Page revision date 3/2011 Copyright 2009 |
Side View
| Beam direction |
| Coax Feed Point |
| Driver wire |
| Tip Spacer |
| Spreaders |
| Center Post |
| Reflector wire |
Table of contents
General
Overall Description
Broadband vs Classic
Six Steps to Build It
The Parts
The Mast
Specs and FAQ's
SWR Results
General
Overall Description
Broadband vs Classic
Six Steps to Build It
The Parts
The Mast
Specs and FAQ's
SWR Results
FAQ's
1. Why should I be considering a broad band beam?
Because it performs better than the classic hex beam. And on
top of that it is easier to build and easier to adjust. The only
drawback is that it is slightly larger in diameter by less than
three feet.
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.
(Remember, increasing frequency requires decreasing wire length and
vice versa.)
If you change the reflector lengths be sure and do the same for
the driver wires.
3. How important are the tip spaces?
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. Just use the Conversion Table on this page to
scale the wire lengths shown here for your particular wire
thickness. Also, leave the end spaces as they are shown here.
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
but really, if you can get it higher for DX, go for it. Try to get 20 feet
at least.
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. Use the same table at left 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 is mainly determined by the geometry of your
particular hex beam. Try to get your wires generally parallel, level
with the ground, symmetrical, etc. Spacing can become a
problem if they are too close. In particular, it has been found by
some that if the 10 meter wires are too close to the 12 meter
wires, the two bands can interact with each other. If you can't get
the specified 4 inch spacing between 12 and 10 meters while
keeping the 10 meter wires parallel, that's OK; just pull the wires
down the post a bit; performance will be better.
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. The best price for a ferrite bead balun I have found is at
www.palomar.com.
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, I am selling 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 me.
You get over 200 parts and a 38 page manual. See a
comparison here.
1. Why should I be considering a broad band beam?
Because it performs better than the classic hex beam. And on
top of that it is easier to build and easier to adjust. The only
drawback is that it is slightly larger in diameter by less than
three feet.
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.
- Change in wire length(+,-) = Change in frequency(-,+) X Orig.
wire length / Original frequency
(Remember, increasing frequency requires decreasing wire length and
vice versa.)
If you change the reflector lengths be sure and do the same for
the driver wires.
3. How important are the tip spaces?
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. Just use the Conversion Table on this page to
scale the wire lengths shown here for your particular wire
thickness. Also, leave the end spaces as they are shown here.
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
but really, if you can get it higher for DX, go for it. Try to get 20 feet
at least.
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. Use the same table at left 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 is mainly determined by the geometry of your
particular hex beam. Try to get your wires generally parallel, level
with the ground, symmetrical, etc. Spacing can become a
problem if they are too close. In particular, it has been found by
some that if the 10 meter wires are too close to the 12 meter
wires, the two bands can interact with each other. If you can't get
the specified 4 inch spacing between 12 and 10 meters while
keeping the 10 meter wires parallel, that's OK; just pull the wires
down the post a bit; performance will be better.
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. The best price for a ferrite bead balun I have found is at
www.palomar.com.
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, I am selling 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 me.
You get over 200 parts and a 38 page manual. See a
comparison here.
|
| Wire conversion table To convert lengths in the tables above to a wire of different gauge (thickness) multiply the lengths above by the factors below for the new desired gauge. |
Units are Inches
1 inch = 2.54 cm
1 inch = 2.54 cm