Four Stage FM Transmitter Circuit Project This transmitter is meant only for educational purposes. Use of this transmitter with outdoor antenna is illegal in most parts of the world. The author and EFY will not be responsible for any misuse of this 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 »
Here the SW transmitter circuit based on IC BEL1895. This particular transmitter circuit works in shortwave HF band (6 MHz to 15 MHz), and can be applied for shortrange communication and for educational purposes. The circuit is composed of a mic amplifier circuit, a variable frequency oscillator, and modulation amplifier stages. Transistor T1 (BF195) is… Read More »
This the Good Quality FM transmitter for your stereo or any other amplifier gives you a pretty good signal strength up to a range of 500 metres having a power output of about 200 mW. This circuit can be operated with a 9V battery. The audio-frequency modulation stage is constructed close to transistor BF494 (T1),… Read More »
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 »
The following diagram is the schematic diagram of 4 transistors FM transmitter circuit designed by Paul K. Sherby. Components List: R1,R2,R8 = 1K R3 = 100K R4 = 150K R5,R7 = 10K R6 = 220 ohm R9 = 10 ohm P1 = 5K trimpot D1 = 1N4002 Q1,Q2 = 2N3904 Q3,Q4 = 7001, NTE123AP C1… Read More »
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 »
This is the simple and low cost AM transmitter schematic diagram built using transistor BC109C. The circuit is in two halfs, an audio amplifier and an RF oscillator. The oscillator is built around Q1 and associated components. The tank circuit L1 and VC1 is tunable from about 500kHz to 1600KHz. These components can be used… Read More »
This is the schematic diagram of Infrared (IR) cordless headphone. Maybe it also can be called “wireless headphone”, but it use infrared as sound signal carrier. It use a pair of circuit diagrams that are IR transmitter and IR reveiver. Using this low-cost project one can reproduce audio from TV or other electronic devices without… Read More »