AM Tuned Radio Frequency (TRF) Receiver

Описание: This is a 3 transistor TRF AM receiver. The detector stage consists of Q3, R5, R6, R7, and C5.

Make sure to only use the Antenna (A) and Ground (G) pins and leave the Oscillator (O) pin unconnected when using an ordinary PVC variable capacitor. The sound quality can be improved by reducing the number of turns of L2 from 6 turns to 3 turns. A breadboard maybe used in constructing the receiver since it operates from 530Khz to 1.6Mhz.

Parts list
1pc ferrite rod/bar for AM (MW) band
Magnet wire (Use gauge 22 to 28 for the ferrite antenna)
1pc AM (MW) band variable capacitor or a 120pF variable capacitor
4pcs 2.2nF (222) capacitor
1pc 1uF electrolytic capacitor
1pc .1uF (104) capacitor
1pc 22uF capacitor (can use higher value)
2pcs 100K resistor
1pc 220K resistor
4pcs 2.2K resistor
3pcs NPN general purpose transistors
1pc switch

A power supply of 3 to 6 volts is required and can use a 3.7 volts battery. Any general purpose NPN transistors can be used such as 2N2222, 2SC945, 9013, 9018 and others. Ceramic capacitors maybe used instead of Mylar capacitors. The receiver does not have an audio amplifier stage so a simple audio amplifier can be used such as a PC speaker.