A.M. Diode Detector
A.M. Diode Detector- Fig-1 shows a simple sensor circuit employing vacuum diode and sludge circuit.
The modulated surge of asked frequence is name by the resemblant tuned circuit
L1C1 and is apply to the vacuum diode.
During the positive half- cycles of modulated surge, the diode conducts while during negative half- cycles, it does not.
The result of this debugging action is that affair of the diode consists of
positive half- cycles of modulated surge as shown.
The debugged modulated swell contains radio frequence and the signal and can not be fed to the speaker for sound reduplication.
Still, no sound will be hear due to the inertia of speaker if done so diaphragm.
The r.f. element is screen by the capacitor C shunt across the speaker.
The value of this capacitor is sufficiently large to present low reactance to the r.f. element while presenting a fairly high reactance to the audio signal.
The result is that the r.f. element is bypass by the capacitor C and the signal is pass on to the speaker for sound reduplication.