Radio transmitters for communities

Our technical team leads by Ali Touré is working on a new model of radio transmitters.

This is an amelioration of the first version used in northern Mali. The first prototype of the new version is already made and tested with success. We hope to use that new version with an LCD screen for the new radio stations in northern Mali.

You must know that in this part of the country, there is no media such as television, internet or radio.
Then, those radio stations are welcome for the safe of population. They will have informations about everything (healthcare,news, etc...).

How does a transmitter works?
This depends in part on what you mean by transmitter. Transmitter can refer to an entire radio set responsible for transmitting a signal, or just the particular bits of such a set that amplify the signal up to a high enough level to be detectable once radiated.

The first thing a transmitter needs is a carrier signal. this is the radio frequency it will transmit at. (Radio frequency, or RF, is an electrical variation in the thousands, millions, or even billions of times per second)

The next thing it needs is intelligence. (something we're actually trying to transmit, such as music or a voice) This is modulated onto the carrier frequency in one of two ways. Frequency Modulation (FM) is where the intelligence varies the frequency of the carrier signal. And Amplitude Modulation, (AM) where the transmitted strength is varied instead.

After these two signals are provided, a transmitter just has to amplify them. The exact amount varies, from a few watts for a cell phone, to millions of watts for high powered RADARs. The methods of amplifying usually include either transistors, (simple electronic components that increase power by acting like a gate on a larger power source), or Vacuum tubes (think "really fancy light bulbs") that accomplish the same thing as a transistor.

Geekcorps's transmitter
Our transmitters look like shown on picture. This one is a prototype we made for tests.


This transmitter can send a signal on 50Km around. Communities can receive the signal on a radio receiver
using a predefine frequency.

Transmitter's box
It is an iron box with 7 differents points.

1- Two plugs cable coming from audio out.
2- LED, shows the transmitter is running.
3- LCD screen's entry
4- Support for sound card component, LCD screen component and exciter component.
5- Two plugs cable coming from the battery(12V) and a fuse.
6- DC converter
7- Amplifier


Transmitter's components