Extra Class

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?

Which of the following is used to shunt feed a grounded tower at its base?

What is the purpose of using multiple driven elements connected through phasing lines?

What is the velocity factor of a transmission line?

Which of the following has the biggest effect on the velocity factor of a transmission line?

Why is the electrical length of a coaxial cable longer than its physical length?

What impedance does a 1/2-wavelength transmission line present to an RF generator when the line is shorted at the far end?

What is microstrip?

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz?

How does parallel conductor transmission line compare to coaxial cable with a plastic dielectric?