In radio communications, what does THIS IS indicate?

In radio communications, what does THIS IS indicate?

• A. Indicates to the receivers the intended party for the message.
• B. Alerts the receiver as to who is sending the transmission.
• C. Alerts the receiver that the sender has ended his transmission and is awaiting a response from the receiver.
• D. Alerts the receiver that the sender has ended his transmission and requires or expects no response/answer.

Answer: (B)

This is used to identify the transmitting station. When a radio transmission begins with THIS IS, the speaker is announcing who is speaking, typically followed by the station’s call sign or unit designation. This identification lets the receiver know exactly who is sending, which is crucial on busy channels or in multi-unit operations so the message can be directed, logged, and replied to properly. It’s not about who the message is for, and it doesn’t signal that the sender has finished or that no response is required—that latter function is conveyed by other standard phrases like Over (for awaiting a reply) or Out (no response expected).

This is used to identify the transmitting station. When a radio transmission begins with THIS IS, the speaker is announcing who is speaking, typically followed by the station’s call sign or unit designation. This identification lets the receiver know exactly who is sending, which is crucial on busy channels or in multi-unit operations so the message can be directed, logged, and replied to properly. It’s not about who the message is for, and it doesn’t signal that the sender has finished or that no response is required—that latter function is conveyed by other standard phrases like Over (for awaiting a reply) or Out (no response expected).