A Simple FM Stereo Transmitter
using an AVR microcontroller.
A very simple stereo encoder that produces good channel separation yet requires only an
inexpensive microcontroller and a few passive components.
Find updates at www.projects.cappels.org
This project appeared in the December, 2007 issue of Info Elektronika Magazine.
Notice: Before operating a radio transmitter, find out what kind of transmitter operation, if any, is permitted in your locality. Radio transmitter operation is a serious legal matter. In the United States, operation of unlicensed intentional radiators is covered by Part 15 of Title 47 of the Code of Federal Regulations. This design can be readily adapted to different frequencies and different power levels. If you choose to build and operate the transmitter described here, you do so at your own risk. I'm only publishing this as an example of what can be done.
(http://www.cappels.org/dproj/FM_MPX_STEREO/SimpleFMStereo.jpg)
Photo 1. In the picture above,
The parts to the right of the green capacitor are the FM radio transmitter.
The parts between the 8 pin DIP and the transmitter are the resistor matrix.
One capacitor, C5, is mounted on the back of the board, and one other capacitor,
C11, had not yet been installed. It was later installed just below the 560k resistor.
The connector in the upper-left is the unregulated power input. The connector in the
lower middle is audio input. ATTINY12, ATTINY25, and AT90S2323 were tested on this board
while the ATTINY2313 and AT90S2313 were tested in another breadboard.
(http://www.cappels.org/dproj/FM_MPX_STEREO/classic.gif)
(http://www.cappels.org/dproj/FM_MPX_STEREO/method.gif)
(http://www.cappels.org/dproj/FM_MPX_STEREO/sidebands.jpg)
(http://www.cappels.org/dproj/FM_MPX_STEREO/viauc.gif)
(http://www.cappels.org/dproj/FM_MPX_STEREO/FMStereoCoder.gif)
(http://www.cappels.org/dproj/FM_MPX_STEREO/stereoboardphoto.jpg)
download hex nya silahkan disini
http://www.cappels.org/dproj/FM_MPX_STEREO/SIMPLE%20FM%20STEREO%20MULTIPLEX%20ENOCDER%20CIRCUIT.html (http://www.cappels.org/dproj/FM_MPX_STEREO/SIMPLE%20FM%20STEREO%20MULTIPLEX%20ENOCDER%20CIRCUIT.html)