Teaching is with no line number sign indicating number public address set

The utility model relates to a public address set is used in the teaching. A teaching is with no line number sign indicating number public address set, including no line number sign indicating number emitter and no line number sign indicating number receiving arrangement two parts, no line number sign indicating number emitter is by the pickup circuit, amplifier circuit and coding circuit constitute, speech signal enlargies back and code signal mixing through the amplifier, launch high frequency carrier signal through high frequency electric way modulate, no line number sign indicating number receiving arrangement includes the wireless receiving module, the decoding circuit, power amplifier, the wireless receiving module is received modulating signal and is carried out the demodulation, separate and access mixing signal output to decoding circuit, decoding circuit output signal passes through low pass filter circuit filtering high frequency code signal, it inserts the speaker to detect low frequency speech si