G9D - Antennas and Feed Lines
General Class
Feed lines and matching: impedance, SWR, baluns, transmission line types
12 questions | Updated: Dec 9, 2025
Which of the following antenna types will be most effective as a near vertical incidence skywave (NVIS) antenna for short-skip communications on 40 meters during the day?
What is the feed point impedance of an end-fed half-wave antenna?
In which direction is the maximum radiation from a VHF/UHF “halo” antenna?
What is the primary function of antenna traps?
What is an advantage of vertically stacking horizontally polarized Yagi antennas?
Which of the following is an advantage of a log-periodic antenna?
Which of the following describes a log-periodic antenna?
How does a “screwdriver” mobile antenna adjust its feed point impedance?
What is the primary use of a Beverage antenna?
In which direction or directions does an electrically small loop (less than 1/10 wavelength in circumference) have nulls in its radiation pattern?
Which of the following is a disadvantage of multiband antennas?
What is the common name of a dipole with a single central support?