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Simple transistor audion

     This is a simple solid state (transistor, semiconductor) short wave radio receiver of audion type with one RF stage and two audio stages. The receiver is tuned by 200p and 20p capacitors (coarse and fine). Potentiometer P1 adjusts feedback. P2 is the volume control. If the receiver is well tuned it can receive also SSB. The antenna consists of a long wire. Received frequency is about 3 - 28MHz. The band is selected by changing the inductance of the coil. My coil is set to receive 20m. The receiver can be powered by a stabilized source of 6 - 12V or 9V battery. Audion creates interference at his own receiving frequency and may disturb nearby receivers.

Schematic of the simple transistor audion.

Schematic of the simple transistor audion drawn in better quality (thank to Dr.house who redraw my schematic).