Ham Radio General Class Test Station Setup and Equipment 2 — Questions and Answers
Question 1: What is the main advantage of using a linear amplifier in an amateur radio station?
- It improves receiver sensitivity
- It increases transmitter output power beyond the transceiver's built-in level (Correct answer)
- It reduces the noise floor
- It filters harmonics automatically
Correct answer: It increases transmitter output power beyond the transceiver's built-in level
A linear amplifier boosts the transceiver's output power (typically 100 W) to higher levels (up to the legal limit of 1500 W PEP output).
Question 2: What is the maximum legal transmitter power output for a General class licensee on HF bands in the United States?
- 100 watts PEP
- 500 watts PEP
- 1000 watts PEP
- 1500 watts PEP (Correct answer)
Correct answer: 1500 watts PEP
FCC Part 97 allows General class licensees up to 1500 watts PEP output on authorized HF bands.
Question 3: What type of power supply is preferred for modern HF transceivers?
- A battery-only system
- A regulated DC power supply providing 13.8 VDC (Correct answer)
- An unregulated transformer supply
- A 24 VDC high-voltage supply
Correct answer: A regulated DC power supply providing 13.8 VDC
Modern HF transceivers are designed to operate from 13.8 VDC, the standard regulated voltage also compatible with 12 V vehicle electrical systems.
Question 4: What is the purpose of an RF choke in an amateur radio station's DC power lead?
- Increase DC voltage to the transceiver
- Prevent RF from entering the power supply and causing interference (Correct answer)
- Regulate current to the transceiver
- Filter audio noise from the receiver
Correct answer: Prevent RF from entering the power supply and causing interference
An RF choke (ferrite bead or toroid on the power leads) presents high impedance to RF while passing DC, isolating the power supply from RF currents.
Question 5: What advantage does a digital voice recorder connected to a transceiver provide during a contest or DXpedition?
- Automatically logs contacts to ADIF format
- Allows repetitive call signs and contest exchanges to be sent with one button press (Correct answer)
- Provides real-time frequency readout
- Filters adjacent channel interference
Correct answer: Allows repetitive call signs and contest exchanges to be sent with one button press
A DVR lets operators record and replay standard phrases (CQ calls, exchange information) to reduce fatigue and improve operating efficiency.
Question 6: What is the purpose of the automatic level control (ALC) circuit in an HF transceiver?
- Automatically tune the antenna
- Control the audio output volume
- Prevent the power amplifier stages from being overdriven and generating distortion (Correct answer)
- Regulate the DC supply voltage
Correct answer: Prevent the power amplifier stages from being overdriven and generating distortion
ALC feeds back a control voltage to reduce drive when the PA approaches its limits, keeping the signal clean and within specification.
Ham Radio General Class Test Station Setup and Equipment 2
What is the main advantage of using a linear amplifier in an amateur radio station?