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how does am get generated in a transistor

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abishek

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say using a bf194 or some transisitor and giving m(t) at collector and carrier at base and with a bias at the bias how do we get am at the collector?
also called COLLECTOR AMPLITUDE MODULATOR somebody pls gelp
thanx
 

flatulent

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One further requirement is that the base drive is high enough to make the amplifier stage be in class C at all Vcc values.

Varying Vcc varies the output power. The Vcc is the sum of a DC term for the carrier and an AC term for the audio making the modulation sidebands.

In the old days this was done with a transformer. The AC was put to the primary and the secondary was in series with the DC and the valve/tube being modulated.

There were alternate ways of doing this. Amateurs would sometimes modulate a 1W transmitter by absorbing the power to the antenna. A carbon microphone was put in series with the antenna transmission line.
 

electronics_kumar

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abishek said:
say using a bf194 or some transisitor and giving m(t) at collector and carrier at base and with a bias at the bias how do we get am at the collector?
also called COLLECTOR AMPLITUDE MODULATOR somebody pls gelp
thanx


abishek how come your saying that it is a collector modulator ..why not to be called as base modualtor?
 

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