Ham Radio General Class Practice Test

What is the name of the process that changes the phase angle of an RF wave to convey information?

1. Phase convolution

2. Phase modulation

3. Angle convolution

4. Radian inversion

The correct answer is: Phase modulation

The correct answer is phase modulation. This technique is widely used in radio communications to encode information by altering the phase of a carrier wave. In phase modulation, the phase of the RF signal is varied in proportion to the instantaneous amplitude of the input signal, which conveys information such as voice or data. Phase modulation allows for effective transmission over various distances and through different mediums, maintaining the integrity of the transmitted information despite potential interference. The options that are not correct do not relate to the established methods of modulating signals in radio communications. For instance, phase convolution and angle convolution are not recognized modulation techniques, while radian inversion does not pertain directly to the process of conveying information through RF waves. Understanding phase modulation's role in encoding and transmitting information is fundamental to grasping how radio communication works effectively.