Pocket size FM radio station

jojo January 21, 2009 41 Comments
The above video claims  you can make a pocket size FM radio station and  the highlight is you dont need an antenna to do this. A small battery is enough to power and it will last for 5 to 7 hrs. This small battery powered FM radiostation even dont need a antenna to broadcast your program into the entire neighborhood for up to a mile or more . It use’s a Onboard Magnetic Loop Antenn, which is the outside...
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FM adaptor circuit for car stereo

jacky April 7, 2010 7 Comments
Description. With this compact FM adaptor circuit plugged into the audio out of your cassete player or i Pod out put,you can listen your favorite music on your car stereo.This circuit is very useful if your car stereo doesnot have an auxillary in socket.The circuit is nothing buy  an short range  FM transimitter. The FM transmitter circuit is based on low power NPN transistor 2N2222.The tank circuit consisting of L1 & C1 producess the necessary oscillations at the collector...
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IR to RF converter circuit.

admin May 18, 2009 23 Comments
Description. The IR to RF transmitter circuit given here can convert the IR signals from your remote to RF signals to long distances. The circuit given here is a good one for extending the range of your IR remote.Also such systems does not need a line of sight since RF signals are used. The transmitter is based on a St-TX 01 ASK transmitter IC (IC2).The IR signals falling on IC 1 (TSOP 1738) will be converted to RF signals...
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Versatile FM Transmitter

admin May 7, 2008 19 Comments
Description. Here is the circuit diagram of a versatile FM transmitter that doesn’t have a coil. The circuit is simple and easy to assemble. The gate N1 acts as a buffer for strengthening the signals from the condenser microphone. The inverter N2 with its  associated components forms a radio frequency oscillator in the FM region.The varicap diode  BB109 is used for frequency modulating the audio signal to the carrier wave generated by the oscillator.Inverters N4 t0 N6 are used...
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FM telephone bug.

admin May 2, 2008 19 Comments
Description. A simple telephone transmitter circuit that is ideal for transmitting the telephone conversation through small distances.The circuit is very simple and uses only few components.The entire circuit can be easily included in the telephone itself or in the junction box.The circuit is powered from the telephone line itself. The transistor Q2 is wired as a a Colpitts oscillator to produce oscillations in the FM transmission band.The audio signal from the telephone line is coupled to the the base...
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FM Tracking transmitter

jacky March 8, 2012 23 Comments
Description. The circuit presented her will transmit a audio tone in the FM  band. The circuit can be used as a tracking signal transmitter or a remote control transmitter. The circuit uses only easily available components and any one can build this. The transmitter has a range of 100m @ 9V supply, with a matching antenna. The NE555 timer (IC1) is used for producing the audio tone. The first JFET (Q1) is wired as a Hartley oscillator which is...
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Simplest FM Transmitter.

admin March 7, 2012 21 Comments
Description. Here is the circuit diagram of the simplest FM transmitter using a transistor. Great performance or range is not guaranteed here, because this is an elementary design. General purpose radio frequency transistor BF 494 (Q1) is used here for obtaining FM modulation. A condenser mic is used here to pickup the sound. The condenser mic converts the sound to electrical variations and this variations are fed to the base of Q1, which performs the amplification as well as...
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Single chip FM transmitter circuit

admin November 27, 2018 21 Comments
Single chip FM transmitter An FM transmitter is a device that can transmit audio from an audio device as a radio signal. Doing so allows the audio to be picked up and played by an FM radio in the transmitter’s range. The FM (frequency modulation) device allows the waves to move in predefined frequencies so it can be identified by a radio tuned o this particular frequency range. FM transmitters can be made in different ways. Circuitstoday alone has...
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Long Range FM Transmitter

jacky October 15, 2018 137 Comments
In this project, let’s learn how to make a simple “Long range FM transmitter” at low cost using minimal components. As you can see in the diagram, the circuit is simple, easy to build and test. Let’s begin to build our long range FM transmitter. How To Build a Long Range FM Transmitter The use of transmitters which have a more powerful output than the ‘flea-power’ are sometimes required when there are many obstacles in the path of the surveillance transmitter and...
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