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This is a basic and little Two Transistors FM Transmitter. It is perfect for prepared surveillance for the strip from radio Fm or beneficiary of VHF. Obviously, the recreational reason likewise exists and the kids will love having a transmitter that permits representing a radio FM put at an inaccessible spot and like this imagine the mystery specialist.

Two Transistors FM Transmitter 

Activity of the Two Transistors FM Transmitter 

The voice/music caught by the electret mouthpiece, your voice or close individuals' visits, are insidious to the base of the PNP transistor Q1 through C1 (10uF) where is intensified. The resistor R2 together with R3 it decides this intensification.

Subsequent to having intensified, the sign is expelled from the authority of Q1 transistor and underhanded to the base of Q2 transistor (NPN), where it tweaks in recurrence the sign created by this stage. This stage is an oscillator of high recurrence that works in the piece of FM. Your recurrence is dictated by L1 (0.3uH) and for the modification on the variable capacitor (CV).

The got signs, effectively balanced in recurrence, they are devilish to a connected radio wire in the gatherer of the transistor Q2 (BC557 Transistor).

The scope of the transmitter relies upon this recieving wire, of the encouraging of the circuit and of where it is working. In the open field, with 6 V battery and a radio wire of around 40 cm of length, this scope of this Tow Transistors FM Transmitter can be 1000 meters. With a littler recieving wire, the scope of this transistor will decrease. A typical divider isn't an impediment for this transmitter.

Circuit DiagramTwo Transistors FM Transmitter 



Q1 – BC557

Q2 – BF494

MIC–receiver electret two terminals

Resistors: (1/4 W, 5%)

R1–4,7 Kω

R2–220 Kω

R3–22 Kω

R4–10 Kω

R5–6,8 Kω

R6–47 Ω




C3–10 nF – fired

C4–4,7 pF – fired

C5–100 nF – fired

CV–trimmer from 3-30 to 5-50 pF

Different Parts:

L1 – 0.3uH

B1 – 3 to 9 V

Insect – radio wire

Printed Circuit Board With Full Detail is given Below

Two Transistors FM Transmitter Printed Circuit

The most effective method to Make FM Transmitter

Full Discussion about this circuit you can openly examine.

Thanx a ton

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