What must an employee operating a radio ensure before transmitting?

An employee operating a radio must ensure that the channel is not being used before transmitting to maintain effective communication and avoid interference. This practice is essential in preventing multiple parties from talking over each other, which can lead to misunderstanding or loss of important information. By confirming the channel is clear, the employee helps ensure that their message is conveyed without disruption, facilitating safe and efficient operations on the railroad.

While being near a control tower, having a fully charged battery, and speaking clearly are all important factors for effective communication, they do not directly address the priority of ensuring the channel is available for transmission.