What device increases the transmitted output power from a transceiver?
The correct answer is B: An RF power amplifier. An RF power amplifier is a device that increases the transmitted output power from a transceiver. It takes the relatively low power output from the transceiver (typically 5-100 watts) and amplifies it to higher levels (100-1500+ watts) for more effective transmission. For amateur radio operators, power amplifiers are used when you need more output power than your transceiver provides, such as for weak-signal work, DX operation, or when operating portable with limited transceiver power. Power amplifiers are separate units that connect between your transceiver and antenna, and they require proper tuning and operation to work correctly and safely.
Exam Tip
RF power amplifier = increases output power. Think 'P'ower 'A'mplifier = 'P'ower 'A'mplification. Voltage dividers reduce voltage, impedance networks match impedances - neither increases power.
Memory Aid
"RF power amplifier = increases power. Think 'P'ower 'A'mplifier = 'P'ower 'A'mplification. Takes low power in, gives high power out."
Real-World Application
Your transceiver outputs 50 watts, but you need 500 watts for a difficult DX contact. An RF power amplifier takes your 50-watt signal and amplifies it to 500 watts, giving you 10 dB more power. This significantly improves your signal strength at the receiving end, making the contact possible. The amplifier is a separate unit that requires proper tuning and cooling.
Key Concepts
Why Other Options Are Wrong
Option A (Voltage divider): Incorrect. A voltage divider reduces voltage, not increases power. It divides voltage between components, actually reducing available power.
Option C (Impedance network): Incorrect. An impedance network matches impedances for efficient power transfer but doesn't increase power. It ensures maximum power transfer but doesn't amplify.
Option D: Incorrect. Since A and C don't increase power, 'all of the above' cannot be correct. Only power amplifiers actually increase output power.
题目解析
The correct answer is B: An RF power amplifier. An RF power amplifier is a device that increases the transmitted output power from a transceiver. It takes the relatively low power output from the transceiver (typically 5-100 watts) and amplifies it to higher levels (100-1500+ watts) for more effective transmission. For amateur radio operators, power amplifiers are used when you need more output power than your transceiver provides, such as for weak-signal work, DX operation, or when operating portable with limited transceiver power. Power amplifiers are separate units that connect between your transceiver and antenna, and they require proper tuning and operation to work correctly and safely.
考试技巧
RF power amplifier = increases output power. Think 'P'ower 'A'mplifier = 'P'ower 'A'mplification. Voltage dividers reduce voltage, impedance networks match impedances - neither increases power.
记忆口诀
RF power amplifier = increases power. Think 'P'ower 'A'mplifier = 'P'ower 'A'mplification. Takes low power in, gives high power out.
实际应用示例
Your transceiver outputs 50 watts, but you need 500 watts for a difficult DX contact. An RF power amplifier takes your 50-watt signal and amplifies it to 500 watts, giving you 10 dB more power. This significantly improves your signal strength at the receiving end, making the contact possible. The amplifier is a separate unit that requires proper tuning and cooling.
错误选项分析
Option A (Voltage divider): Incorrect. A voltage divider reduces voltage, not increases power. It divides voltage between components, actually reducing available power. Option C (Impedance network): Incorrect. An impedance network matches impedances for efficient power transfer but doesn't increase power. It ensures maximum power transfer but doesn't amplify. Option D: Incorrect. Since A and C don't increase power, 'all of the above' cannot be correct. Only power amplifiers actually increase output power.
知识点
RF power amplifiers, Output power increase, Transmitter accessories, Power amplification
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.