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+----- Thread: AM wave generation and capture, with transistor audio amp! (/thread-13791.html)
AM wave generation and capture, with transistor audio amp! - greatgamer34 - 03-16-2018
In this video I demonstrate a 3 transistor circuit that acts like a tune-able diode, with a Common Emitter NPN BJT transistor.
*First I review basic AM waves and what they are.
*Then I try to show the most basic way to capture a Pure AM signal with a Diode and RC envelope Detector.
*Next I describe how engineers are not mathematicians so we do not need to derive every transform that we need(Z, Fourier, Laplace, etc, etc..)
*With that in mind, I review how to move a low frequency content into a higher frequency by multiplication of a complex exponential or sinusoidal signal.
*I explored a Modulation Table that shows the form of the carrier signals for all different forms of AM(AM, DSB, VSB, SSB, and QAM). This table also shops the respective Fourier Transform, Magnitude and Phase spectrum(with respect), Bandwidth, Power, and Modulation and Demodulation methods.
*Next I explored my MicroElectronics textbook for a MOSFET CS amplifier(which is the MOSFET equivalent to a BJT Common Emitter Amplifier used in my circuit.)
*Lastly I simulate an AM signal and then rectify and amplify it to produce an output to emit to a speaker
