Refers to a device that sends signals, such as radio, television, or data transmissions. Common in technical and broadcasting contexts.
This transmitter can send signals within a 5-kilometer radius.
The radio station's transmitter broke down and the broadcast was interrupted.
送信機 sends signals while 受信機 receives them, making them functional opposites.
送信機 sends out signals while レシーバー (受信機) receives them, making them opposite ends of a communication link.
Compound of 送信 (transmission) + 機 (machine/device). The term is a straightforward technical coinage from the late 19th or early 20th century, reflecting the adoption of modern communication technology.