FREE Ham Radio Extra Class MCQ Questions and Answers Flashcards

What is the primary advantage of a Beverage antenna for receiving on the low HF bands?

Answer: Excellent directivity and low-angle reception with good signal-to-noise ratio

A Beverage antenna is a long-wire receiving antenna prized for its excellent directivity and favorable signal-to-noise ratio on the low HF bands.

What is the purpose of dither in an analog-to-digital converter used in a software-defined radio?

Answer: To reduce quantization noise by adding a small amount of random noise

Dither adds a small amount of random noise to the input signal, which linearizes quantization errors and improves the effective resolution of the ADC.

Which of the following describes the Near Vertical Incidence Skywave (NVIS) propagation technique?

Answer: Transmitting signals nearly straight up so they reflect back down within a radius of about 300 miles

NVIS uses high-angle radiation directed nearly vertically so the ionosphere reflects signals back down, providing reliable coverage within roughly 300 miles.

What is the effect of mutual coupling between elements of a Yagi-Uda antenna?

Answer: It modifies the current amplitude and phase on parasitic elements to create a directional pattern

Mutual coupling between driven and parasitic elements causes currents to flow with specific amplitudes and phases that produce the antenna's directional radiation pattern.

What is the maximum permitted transmitter peak envelope power for an Amateur Extra licensee on the 60-meter band?

Answer: 100 watts PEP ERP

On the 60-meter band, Amateur Extra class operators are limited to 100 watts PEP effective radiated power relative to a dipole.

What is the primary purpose of a DSP notch filter in an HF transceiver?

Answer: To eliminate a single interfering carrier or tone from the received audio

A DSP notch filter precisely removes a narrow-bandwidth interfering signal such as a heterodyne or carrier tone from the received audio.