One Transistor FM Receiver

One Transistor FM Receiver circuit diagram

This is a very simple FM receiver which build based on one transistor only. No chip or another active component. The output is connected to earphones, you need an amplifier circuit if you want to listen the radio with a loudspeaker.

Part designator Part description
C1a,C1b 10 pf, 50 v, ceramic disc capacitor
C2 22 pf, 50 v, ceramic disc capacitor
C3 RF tuning capacitor
C4 330 pf, 50 v, ceramic disc capacitor
C5,C8 0.001 uf, 50 v, ceramic disc capacitor
C6 0.22 uf, 50 v, film capacitor
C7 0.0047 uf, 50 v, ceramic disc capacitor
C9 22 uf, 16 v, electrolytic capacitor
D1 TL431AIZ voltage control Zener (shunt regulator)
EPH1 High impedance earphone
L2 22 uh RF choke
Q1 2N4416A JFET transistor
R1 470K, 1/4 w, resistor
R2, R3 1K, 1/4 w, resistor
R4 10K, 1/4 w, resistor
R5 1M, 1/4 w, resistor
R6 100 ohm, 1/4 w, resistor
S1 Small SPST switch
screws for C3 screws for mounting C3 (2 needed)
nylon screw #4 nylon screw used for tuning C3
battery connector mini battery snap

L1 determine the frequency of the radio, acts as the antenna, and is the primary adjustment for super-regeneration. Although it has many important jobs, it is easy to construct. Get any cylindrical object that is just under 1/2 inch (13 mm) in diameter. A thick pencil or a magic marker or large drill bit work just fine. #20 bare solid wire works the best, but any wire that holds its shape will do. Wind 6 turns tightly, side-by-side, on the cylinder, then slip the wire off. Spread the windings apart from each other so the whole coil is just under an inch (2.5 cm) long. Find the midpoint and solder a small wire for C2 there. Mount the ends of the wire on your circuit board keeping some clearance between the coil and the circuit board.

More instruction how to build this circuit, visit this page

7 comments

  1. there is no need external antenna for this circuit. The L1 is act as an antenna, it should be enough to catch the FM signal.

  2. please upload mini project on to construct FM transmitter and FM Recevier It is very imp. to GTU B.E. Electronics and communication Student. I think u Providethis facility as soon as possible. thank you

  3. i love this circuit good job but try and create more circuits like this one

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