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。

youdao

An engineer added an AM channel alongside the FM signal so that the station can be heard, on clear days, in places as far away as Europe.

一位工程师在FM信号的旁边又增加了AM频道，在晴朗的天气里，像欧洲那么远的地方都可以听到他们的广播。

youdao

A printing plate comes with sharp detail , whether it's FM or am screening has excellent performance.

印版还具备锐利的细节，无论是调频或调幅加网都有极好的表现。

youdao

FM radio provided better sound reproduction and less noise or interference than traditional AM radio.

VOA: special.2010.01.31

The industry spent much of that time fighting over a plan to move FM and AM to a new spectrum band to accommodate digital.

FORBES: Big Audio Dynamite

The Digital Radio Working Group (DRWG) says that by 2015, less than half of all radio listening could be via traditional FM or AM sets.

BBC: Radio 'could go digital in 2017'

But by 1978, music had migrated to FM, leaving AM in a programming lurch.

WSJ: Limbaugh Is Right on the Fairness Doctrine