G9B - Antennas and Feed Lines
General Class
Antenna construction and optimization: dipoles, verticals, loading, traps
12 questions
What is a characteristic of a random-wire HF antenna connected directly to the transmitter?
Which of the following is a common way to adjust the feed point impedance of an elevated quarter-wave ground-plane vertical antenna to be approximately 50 ohms?
Which of the following best describes the radiation pattern of a quarter-wave ground-plane vertical antenna?
What is the radiation pattern of a dipole antenna in free space in a plane containing the conductor?
How does antenna height affect the azimuthal radiation pattern of a horizontal dipole HF antenna at elevation angles higher than about 45 degrees?
Where should the radial wires of a ground-mounted vertical antenna system be placed?
How does the feed point impedance of a horizontal 1/2 wave dipole antenna change as the antenna height is reduced to 1/10 wavelength above ground?
How does the feed point impedance of a 1/2 wave dipole change as the feed point is moved from the center toward the ends?
Which of the following is an advantage of using a horizontally polarized as compared to a vertically polarized HF antenna?
What is the approximate length for a 1/2 wave dipole antenna cut for 14.250 MHz?
What is the approximate length for a 1/2 wave dipole antenna cut for 3.550 MHz?
What is the approximate length for a 1/4 wave monopole antenna cut for 28.5 MHz?