Extra Class

How much does the gain of an ideal parabolic reflector antenna increase when the operating frequency is doubled?

How can two linearly polarized Yagi antennas be used to produce circular polarization?

What is the most efficient location for a loading coil on an electrically short whip?

Why should antenna loading coils have a high ratio of reactance to resistance?

Approximately how long is a Yagi’s driven element?

What happens to SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

What is an advantage of top loading an electrically short HF vertical antenna?

What happens as the Q of an antenna increases?

What is the function of a loading coil in an electrically short antenna?

How does radiation resistance of a base-fed whip antenna change below its resonant frequency?

Why do most two-element Yagis with normal spacing have a reflector instead of a director?

What is the purpose of making a Yagi’s parasitic elements either longer or shorter than resonance?

Which matching system for Yagi antennas requires the driven element to be insulated from the boom?

What antenna matching system matches coaxial cable to an antenna by connecting the shield to the center of the antenna and the conductor a fraction of a wavelength to one side?

What matching system uses a short length of transmission line connected in parallel with the feed line at or near the feed point?

What is the purpose of the series capacitor in a gamma match?

What Yagi driven element feed point impedance is required to use a beta or hairpin matching system?

Which of these transmission line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm feed point impedance to a 50-ohm transmission line?

What parameter describes the interaction of a load and transmission line?

What is a use for a Wilkinson divider?