Antenna Werks - New Antenna Design
Over the years, I have used a number of the commercial screwdriver style antennas available in the market place. I have always been disappointed with the limiting size of the coil in these antennas, due to the limitations of the mast size that the coil resides in.
For some time, I have been working on a design that would allow me to build a antenna that circumvented this problem. After a lot of thought, I came up with a design that utilizes a coil that has two diameters, the upper section could be of any diameter you desire, and the lower section would be of a smaller diameter that balances off the overall antenna, and yet capable of supporting the complete antenna, But more importantly the small diameter mast would house the lower tail-section of the coil, supporting the upper large diameter section of the coil.
As you can see, I have my prototype antenna built, and it is proving to be what I have always wanted in a screwdriver antenna, a design that does not limit the size of the coil that can be utilized in its construction. I built this antenna with a 3 inch coil, proofing my design, but I also had a particular need for a antenna with these dimensions. Still, the design is sound, and the design that I came up with is capable of using a much larger diameter coil with the same results.
Its been a while since I have got as much satisfaction out of one of my projects, as I have got from designing & building this antenna, and then operating HF mobile with this antenna.
Everything, from my earliest thoughts on what I had in mind for a new antenna design, to the actual designing & building of this antenna has progressed without a glitch.
With the antenna mounted on my mobile, I have proven that the antenna build, works & performs as I imagined that it could.
This antenna with its one of a kind coil assembly is proving to be a very good design, and the 3 inch upper section of the coil, with the smaller diameter tail section of the coil, is wonderful to see in operation. The coil is rock solid with no side to side motion, when extended in the 80 meter position, and will handle the biggest of whips with a included caphat with ease.
The other plus to the design, is the fact that the Delrin tail section moves as smooth as silk in the lower mast housing. The design also allows for a keyway to be cut the length of the lower tail section of the coil, assuring that the coil cannot turn in the housing while being powered along its path by the gearmotor. http://www.jerryclement.ca/photos/i-LT2sKpx/0/L/i-LT2sKpx-L.jpg
The gearmotor powers the coil assembly without any effort, and draws a milliamp sipping 250 milliamps under load.
For those of you who are interested in the work that was done in creating my latest 10/80 meter HF mobile antenna, you will find that by following this link.