What type of modulation does the EF Johnson 5317 use?

The EF Johnson 5317 utilizes Frequency Modulation (FM) for its operation. In FM, the frequency of the carrier wave is varied in accordance with the amplitude of the input signal, allowing for a more robust signal with better noise immunity compared to other modulation techniques. FM is especially beneficial in communications where clarity and quality of audio transmission are essential. This modulation type also provides a wider bandwidth, which can accommodate higher fidelity audio.

In contrast, options like AM (Amplitude Modulation), Single Sideband, and Pulse Width Modulation have different operational principles and applications. While AM varies the amplitude of the carrier wave to convey information, Single Sideband is a more efficient version of AM that transmits only one sideband along with the carrier, and Pulse Width Modulation involves varying the width of pulses in a digital signal. Each of these methods has its specific uses and advantages, but FM is the correct choice in this context due to its application in the EF Johnson 5317.