Infinite Impedance AM Detector

An infinite impedance detector circuit attached to the final intermediate frequency transformer (IFT) in a radio receiver for Hi-Fi quality AM reception.

An FET infinite impedance AM detector circuit boasts several virtues, making it a popular choice for Hi-Fi AM applications:

Superior Audio Quality:

Low distortion: Unlike diode detectors, which can introduce significant distortion, FET infinite impedance detectors exhibit minimal distortion, offering cleaner, crisper audio.
Excellent selectivity: The high input impedance preserves the tuned circuit's Q factor, leading to sharper selectivity and minimized interference from adjacent radio stations.

Low noise: The relatively low operating currents contribute to a quiet output with minimal background noise.