Ham Radio General Class Practice Test

What component is essential for frequency modulation?

1. Phase-locked loop

2. Inductor

3. Capacitor

4. Modulator

The correct answer is: Modulator

Frequency modulation (FM) is a technique in which the frequency of a carrier wave is varied in accordance with the information signal being transmitted. For this process, a modulator is essential. The modulator takes the baseband signal (the original information signal) and varies the frequency of the carrier wave to create the frequency-modulated signal. In frequency modulation, the modulator integrates the input audio or data signal to affect the frequency of the carrier signal. This is vital for ensuring that the information is accurately encoded onto the carrier wave for efficient transmission and reception. While other components, such as phase-locked loops, inductors, and capacitors, may play supporting roles in RF systems, they are not fundamental to the process of frequency modulation itself. The modulator is the core component that directly implements the modulation technique needed to create the FM signal.