4 Stage FM Transmitter

This is the FM transmitter circuit which apply 4 radio frequency stages, that are a VHF oscillator designed around transistor BF494 (T1), a preamplifier designed around transistor BF200 (T2), a driver designed around transistor 2N2219 (T3) and also a power amplifier designed around transistor 2N3866 (T4). A condenser microphone is wired at the input of… Read More »

2 Transistor Mini FM Transmitter

This is a mini FM transmitter built and powered using 2 transistors, designed by Tony van Roon. This small transmitter is simple to build and its transmissions could be picked up on any common FM radio. It possesses a range of approximately 1/4-mile (400 meters) or even more, depending on the line-of-sight, obstructions by big… Read More »

4 Transistor FM Tracking Transmitter

The following diagram is the FM tracking transmitter based on 4 transistors. No additional notes for this tracking transmitter diagram, try to discover this circuit by yourself.. 🙂 Components list: R1 = 100K Ohms R2 = 10 Ohms R3 = 47K Ohms R4 = 220 Ohms C1 = 4.7uF/16V C2, C5 = 1nF C3 =… Read More »

Three Stage 9V FM Transmitter

This circuit is a powerful three stage, 9V FM transmitter (Tx) with a range of up to 1 kilometer in the open. It uses an RF transistor in its output stage and two BC547″s for the first two stages. Distance of trans-mission is critically dependent on the operating Conditions (in a building or out on… Read More »