2KM Long Range FM Radio Transmitter

This long-range FM radio transmitter has an additional RF power amplifier stage, after the oscillator stage. The extra RF power amplifier used to strenght up the power output to become 200-250 milliwatts. With a great matching multi-element Yagi antenna or 50-ohm ground—plane antenna, this transmitter can give great good signal strength up to a distance… Read More »

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 »

FM Receiver with TDA7021T

This is the circuit diagram of mini FM receiver that build based on single FM IC TDA7012T. Components List: R1 = 8kΩ2 R2 = 10kΩ R3 = 390Ω C1,C3 = 10nF C2,C6,C9,C16 = 100nF C4 = 33pF C5 = 25pF trimmer (Murata type TZB4Z250AB10R00) C7,C10 = 1nF5 C8 = 820pF C11 = 1nF C12 =… 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 »

15W FM RF Amplifier with 2SC2539

This is a 15W FM RF amplifier circuit which build based on RF Power Transistor 2SC2539. 2SC2539 is a silicon NPN epitaxial planar type transistor designed for RF power amplifiers in VHF band mobile radio applications. FM RF Amplifier Circuit Diagram: Coil Specifications: L1: 2T Coil diameter:4mm L2: in series 6pcs Toroidal ring L3: 4T… Read More »