The test result indicates that the phase modulator without transformer can suppress the carrier wave.

实测结果表明，这种无变压器环形相位调制器能较好地抑制载波。

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Once, before dual voltage became the standard for consumer electronics, there was plentiful physical evidence of the fact that if you plug in across systems without a transformer, the result is either a flame-out or a non-starter.

FORBES: On China Swagger and the Smell of Burning Insulation