GROL - General Radiotelephone Operator License Modulation and Signal Types Questions and Answers

Question 1

Which of the following is a primary advantage of Single-Sideband Suppressed-Carrier (SSB-SC) modulation compared to conventional Amplitude Modulation (AM)?

Accepted Answer

It requires significantly less bandwidth and transmitter power.

Answer

It can be demodulated with a simple envelope detector.

Answer

It provides superior sound fidelity for music broadcasting.

Answer

It is completely immune to all forms of noise and interference.

Question 2

In Frequency Modulation (FM), what characteristic of the carrier wave is varied in direct proportion to the instantaneous amplitude of the modulating signal?

Accepted Answer

Frequency

Answer

Amplitude

Answer

Phase

Answer

Pulse width

Question 3

A technician is analyzing a transmitter that is emitting multiple signals simultaneously. Spurious signals are detected at frequencies that are the sum and difference of the original signal frequencies. What is this phenomenon called?

Accepted Answer

Intermodulation Distortion (IMD)

Answer

Pulse-Code Distortion

Answer

Carrier Suppression Fault

Answer

Phase Jitter

Question 4

Which digital modulation technique involves sampling an analog signal, quantizing the sample's amplitude, and then encoding that value into a binary word?

Accepted Answer

Pulse-Code Modulation (PCM)

Answer

Frequency Shift Keying (FSK)

Answer

Amplitude Shift Keying (ASK)

Answer

Phase Shift Keying (PSK)

Question 5

A J3E emission designator signifies what type of transmission?

Accepted Answer

Single-sideband, suppressed-carrier (SSB) voice telephony

Answer

Frequency-modulated (FM) voice telephony

Answer

Double-sideband amplitude-modulated (AM) voice

Answer

Digital data using phase-shift keying

Question 6

When comparing FM to AM for voice communications, what is a significant disadvantage of FM?

Accepted Answer

FM signals generally have a shorter effective range (line-of-sight) than AM signals at the same frequency.

Answer

FM is more susceptible to noise from atmospheric static and electrical equipment.

Answer

FM transmitters and receivers are technologically simpler and less expensive to build.

Answer

FM requires significantly less spectrum bandwidth to transmit the same information.