Examination Practice Questions And

Illinois Radio Operator Licensing Examination Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• Which of the following frequency bands is commonly used for public

safety radio communications in Illinois?

• 30–50 MHz
• 150–174 MHz
• 450–470 MHz
• 800–900 MHz

Rationale: Public safety agencies often operate in the VHF band of 150–

174 MHz for reliable communication over medium distances.

• What is the primary purpose of a repeater in a radio communication

system? 1 / 4

• Encrypt messages
• Extend the range of radio signals
• Reduce interference
• Convert analog signals to digital

Rationale: Repeaters receive weak signals and retransmit them at higher

power to extend the communication range.

• Which modulation type is most commonly used in two-way radio voice

communication?

• FM
• AM
• PM

D. SSB

Rationale: AM (Amplitude Modulation) is less common for two-way radios;

FM (Frequency Modulation) is standard for voice in modern radios, but some legacy or long-distance systems may use AM.(Note: For Illinois licensing, FM is correct for local VHF/UHF, so we'll adjust)

3. Corrected: Which modulation type is most commonly used in

VHF/UHF two-way radio voice communication?

• AM
• FM
• PM

D. SSB 2 / 4

Rationale: FM (Frequency Modulation) is standard in VHF/UHF bands for

clear voice communication with reduced noise.

• What does the term "duplex" mean in radio communication?
• Two operators using the same frequency simultaneously
• Transmission and reception on separate frequencies

simultaneously

• Sending messages in Morse code
• Using two different radio models

Rationale: Duplex allows simultaneous two-way communication using

separate transmit and receive frequencies.

• Which license class allows a person to operate a commercial radio on

VHF maritime channels in Illinois?

• Technician
• General
• Marine Radio Operator Permit
• Extra

Rationale: The FCC’s Marine Radio Operator Permit is required to operate

commercial maritime VHF radios legally.

• What is the standard emergency frequency for marine VHF

communications?

• 156.050 MHz
• 156.100 MHz 3 / 4

• 156.800 MHz
• 156.200 MHz

Rationale: Channel 16 (156.800 MHz) is the designated international

calling and distress frequency for marine VHF radios.

• What is the purpose of a squelch control on a radio?
• Adjust the volume
• Mute background noise when no signal is present
• Increase transmission power
• Encrypt the transmission

Rationale: Squelch eliminates unwanted static and noise when no signal is

being received.

• What does the term "line-of-sight" mean in radio propagation?
• Signals can bend around obstacles
• Signals travel directly from transmitter to receiver without

obstruction

• Signals follow the curvature of the earth
• Signals penetrate solid metal structures

Rationale: VHF/UHF signals generally travel in straight lines and require a

clear path between antennas.

• Which component converts electrical energy into radio waves?
• Antenna tuner
• Transmitter
• / 4