Table of Contents
How high should a dipole antenna be off the ground?
Recommendation. For best results, dipoles should be at least 1/2 wavelength above ground level. For the lower bands, especially 160-40 meters, this can become impractical–place your dipole as high as your situation allows.
Does a dipole antenna need a ground?
Answer: No. The 1/2 wave antenna (also called a dipole antenna) is built of two 1/4 wave elements that interact with one another to launch the electro-magnetic wave. It does not require a ground plane to work efficiently.
Can a vertical antenna be used for NVIS?
Half-wave dipole antennas are great for NVIS, positioned a fraction of a wavelength above the ground. To direct the greatest portion of the transmitted signal vertically, the antenna must be positioned relatively low to the ground. A height of 1/8 to 1/10 wavelength is often used for effective NVIS.
How do you increase the gain of a dipole antenna?
In order to increase the gain of an antenna, you need to concentrate its effectiveness in the required direction. Two common methods are to concentrate horizontal beamwidth by adding reflectors and directors, thus creating a Yagi beam.
How high should an 80m dipole be?
At a height of thirty-five feet, the 80 meter dipole constructed according to the classic formula and directly fed with 50 ohm coax exhibits a better SWR of 1.1:1 at resonance, but has a 2:1 bandwidth of about 150 kilohertz and a 1.5:1 bandwidth of only 100 kilohertz.
What angle should an inverted antenna be?
90 degree angle
An inverted vee antenna is a type of antenna similar to a horizontal dipole, but with the two sides bent down towards the ground, typically creating a 120 or 90 degree angle between the dipole legs.
How do you ground a dipole antenna?
You should ground the shield of the coax before or at the connection point to the balun, not between the balun and antenna. Remember that the balun conversion between the balanced dipole antenna and the unbalanced coax cable.
What does NVIS stand for?
Near vertical incidence
Near vertical incidence skywave, or NVIS, is a skywave radio-wave propagation path that provides usable signals in the distances range — usually 0–650 km (0–400 miles).