To operate the AN/PRC-77 radio without hearing static, what action should be taken?

To operate the AN/PRC-77 radio without hearing static, turning the function switch to the squelch position is the appropriate action. The squelch function is designed to mute the audio output of the radio unless a signal strong enough to be heard is received. When the squelch is activated, it effectively eliminates background noise, which includes static, allowing the operator to hear only relevant communications.

In various scenarios, other actions like adjusting the volume may increase amplification but won't address static if a signal isn't present. Switching the battery could help if the radio is not functioning properly due to power issues, but it wouldn't specifically resolve static noise. Changing the frequency could potentially lead to clearer communication if interference exists at the current frequency, but it doesn't directly solve the issue of static if the radio is not squelched. Therefore, activating the squelch is the most effective method to ensure a clear signal without unwanted noise.