The transmitters that either working in FM or in AM is familiar. This is transmitters circuit that can transmit both FM and AM signal simultaneously at two different frequencies FM in 100Mhz and Am in 20 MHz. Here is the circuit:
To transmit the FM signal, this circuit uses the 5th harmonics of the fundamental 20Mhz. So the range of the FM signal will be less than am signal. It can also feed the audio signal directly. The amplifier stage is formed by transistor Q1 and Q2 that fed to the modulator. This modulator formed by the nor gates. for good reception we can use a long wire antenna. [Source: cxem.net]
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