noun
transmitting station
A facility that sends out broadcast signals, such as for television or radio.
この山の上にテレビの送信所がある。
There is a TV transmitting station on top of this mountain.
中継局 is a relay station that receives and retransmits signals, whereas 送信所 is the originating transmission point.
Compound of 送信 (transmission) and 所 (place, facility).