The composite video signal is transmitted as an AM signal and the sound as an FM signal on these channels.

在每个频道中，组合视频信号被当作调幅（AM）信号传输，声音信号作为FM（调频）信号传输。

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And yet, the "Wow!" signal is the only reliably recorded sound apparently received from deep space that has the quality of an intentional signal.

目前为止，“哇”信号是来自外太空的故意信号中唯一的比较明显、可靠地记录。

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And while being able to watch TV anywhere is a spectacular idea, there's no signal in the subways, and even above ground, the sound cuts out every few seconds.

手机看电视是个很好的想法，但是在地铁里是没信号的，就算在地面上，信号也是断断续续的。

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AM radio can be sent over larger distances, but the quality of the sound is not as good as a later kind of radio signal processing, called frequency modulation.

VOA: special.2010.12.08

Luckily the signal is strong and the phone's sound quality keeps it a good option for those non-conformists who like to talk on their phones.

ENGADGET: Samsung's "RAZR KILR" A900 reviewed Mobile

One of them is the ability to pair a concept with a signal, or a meaning with a sound.

FORBES: Magazine Article