12 _ Tuned Amplifier Tutorial

Tuned Amplifier Tutorial

Here the load resistor has been replaced by a tuned circuit, C4 and L1.
At resonance, the tuned circuit is high impedance.
At all other frequencies it is a low impedance.
Therefore only signals at the resonant frequency will be amplified

Since the tuned amplifier works at radio frequencies the capacitors can be much smaller in value than those used at audio frequencies