An electronic device that converts one frequency of a radio signal to another. 變頻器將無線電訊號從一種頻率轉換成另一種頻率的電子裝置
I'll cue you in (ie give you a signal to start) by nodding my head. 我一點頭，你就開始。
It is the simplest signal to make, in time of danger or disaster. 這是在遇到危險或災難的時候能發出的最簡單的信號。
An extract from the music for another part printed, usually in smaller notes, within a performer's part as a signal to enter after a long rest. 提示小節在樂譜中為另一聲部作準備的選段，通常用較小的字體印刷，在演奏部分之內，作為在長時間休息后另一聲部進入的信號
