The antenna construction projects you see in antenneX are not very material specific concerning your choices for booms and elements. The reason being is in different parts of the world not all of the materials available here in the U.S. can be obtained as easily. It’s no fun to see something you would like to build only to find the parts are either not available or cost too much for the average person to buy.
For instance, coaxial cable is not readily available in some areas, so you may find antennas there fed by homemade open-wire line. It is not too hard for open-wire line to be built and in some places of the world, a ham can find the wire and insulators to make this type of feedline a lot easier than finding coax.
This is just an example of some of the problems hams in other parts of the world may have and why a lot of the antenna projects do not tell you “go purchase 3 ten-foot fiberglass fishing rod blanks to use for spreaders.” If the ten-foot spreaders are not available somewhere, and the article does not state if you can use other materials, it might discourage someone from building an antenna. This is why it is always stated when substitutions may be made and some suggestions are offered.A case in point is the use of switches used in the load-all antenna coupler to simulate a rotary inductor. Not everyone can find rotary inductors in other parts of the world, so the use of switches to simulate the rotary coil gives an alternate method of varying the inductance. Alligator clips work as well also and is another way to accomplish the same thing.
The point is that sometimes ingenuity is required to overcome a construction problem. I do not know a ham that has been not absolutely frustrated by a project which requires a “special Potrizbie Hum Amplifier available from Veebleflitzer Electronics for $12,098.98, shipping extra”. In the 30 + years that I have had my ticket, it has happened far more times than I care to remember.
So our construction articles will have suggestions for alternate materials or methods to accomplish the same end. The ham in some of our more remote parts of the States has the same problem as our fellow hams in some of the less developed countries of the world, no parts or limited sources.
In a past issue there was an article on a fold-over mast made of wood. The reason it was made of wood is it was the best material to work with in that case and it was cheap. This mast was 48 feet tall, and worked very well until a small tornado clipped it.
Many of the construction articles are based on things I have actually built in the past and feel others should benefit from the information. Antennas are the easiest things to experiment with and the rewards are worth it. Antennas are also the cheapest way to improve your signals. Lots of antennas from the past are very useful today, but for some reason, they have been left in the closet.
For the ham in an underdeveloped country who cannot get aluminum to build a yagi, the JK array made out of bamboo or wood with wire elements taped or tied to the element support material is ideal. It is also just as good an antenna for the ham here in the States who can’t afford a yagi. The lack of test equipment in other parts of the world is also a problem. Thus, I like to describe projects for our less fortunate hams both here and abroad which can be made to work easily with a minimum of test equipment.
No matter what aspect of amateur radio you are in, from DX chasing to ragchewing at night on 75 meters, you like to do it with a minimum of problems. So, being able to substitute less expensive components for what you can obtain locally makes life a lot easier, particularly when you have to build an antenna by necessity. Experiment and enjoy!
Originally posted on the AntennaX Online Magazine by Richard Morrow, K5CNF
Last Updated : 5th March 2024