FM Transmitter


Posted on Feb 7, 2014

This FM transmitter is about the simplest and most basic FM transmitter it is possible to build and have a useful transmitting range. It is surprisingly powerful despite its small component count and 3V operating voltage. It will easily transmit over 300 meters in the open air and even more with higher voltage supply. The circuit we use is based o


FM Transmitter
Click here to download the full size of the above Circuit.

n a proven Australian design. It may be tuned anywhere in the FM band. Or it may be tuned outside the commercial M band for greater privacy. Of course this means you must modify your FM radio to be able to receive the transmission or have a broad-band FM receiver. The output power of FM transmitter is within the legal limits of many countries. However, some countries may ban all wireless FM transmitters without a licence. It is your responsibility to check the legal requirements for the operation and to obey them. FM transmitter is constructed on a single-sided printed circuit board PCB. Components may be added to the PCB in any order. Note that the electret microphone should be inserted with the pin connected to the metal case connected to the negative rail (that is, to the ground or zero voltage side of the circuit). The coil should be about 3mm in diameter and 5 turns. The wire is tinned copper wire, 0. 61 mm in diameter. After the coil in soldered into place spread the coils apart about 0. 5 to 1mm so that they are not touching. (The spacing in not critical since tuning of FM transmitter will be done by the trim capacitor. It is quite possible, but not as convenient, to use a fixed value capacitor in place of the trimcapacitor - say 47pF - and to vary the Tx frequency by simply adjusting the spacing of the coils. That is by varying L of the LC circuit rather than C. ) Adding and removing the batteries acts as a switch....




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Curtain Control Circuit
PIC Light Chaser with PIC16C84
Flood alarm
Audio-power-amplifier
Detector And Controller
Control motor PWM schematic
circuit power audio amplifier with
knight Rider
Phase Locked Loop (PLL) Oscillator Circuit 860 MHz
Filament and Control Power Supplies
2400 MHz RF amplifier circuit diagram using PM2107
EXPANDED SCALE DC VOLTMETER
Sonic depth finder of the amateur fisher
USB Live Oscilloscope: Digital Input Board
GPS Jammer
High pressure natural gas shutoff valve drive circuit diagram



Top