This 34’ 6” telescopic element for 2 through 40 meters is a 1/4-wave vertical antenna that works well with 4 radials. In such a configuration, it will exhibit a radiation pattern with a low take off angle for HF frequencies, which is ideal for long-distance (DX) communication.
Here’s a more detailed explanation:
· 1/4-Wave Vertical Antenna:
This type of antenna is a monopole, meaning it’s a single vertical element that is designed to be one-quarter the wavelength of the radio frequency it’s intended for.
· Let’s use 40 Meters as an example:
For the 40-meter band (7 MHz), a 1/4-wave vertical antenna would be roughly 33 feet (about 10 meters) tall. This will also function well on 15 meters, which is a third harmonic of 40 meters.
· Radials:
Radials are horizontal wires or metal plates connected to the feed point of the antenna, acting as an artificial ground plane.
· Radiation Pattern:
A 1/4-wave vertical antenna with a good radial system will have a radiation pattern that is omnidirectional (all directions) at the horizon, but with a low-angle radiation, which is beneficial for DX (long-distance) communication.
· Benefits of 4 Radials:
· Improved Ground Connection: Radials help to create a better ground connection, which is crucial for the antenna to operate efficiently.
· Better Performance: A good radial system can significantly improve the antenna’s performance, leading to stronger signals and better reception.
· Low-Angle Radiation: The low-angle radiation is ideal for DX communication, as it allows signals to travel further along the Earth’s surface.
· Construction:
· Vertical Element: A telescopic vertical element can be made resonant from 2 through 40 meters should be approximately 1/4 wavelength of the desired frequency.
· Radials: The radials should also be slightly longer than 1/4 wavelength long on the lowest frequency, which in this case is 7MHz.
· Feed Point: The feed point is where the antenna is connected to the radio equipment using 50 ohm coax. The center pin of the feed point attaches to the vertical element, while the barrel or shield of the coax attaches to the radials.