Build a FM radio transmitter

This is a guide to becoming a techno rebel: a guide to becoming a radio pirate and raiding the silent airwaves with your own content. This is a follow up to my recent call for relaxing the grip on radio broadcasting in the Maldives.

One of the easiest transmitters to build is a FM transmitter. A basic low power transmitter can be assembled in a few hours, using a minimal set of equipment and components and best of all, it can be done without denting the wallet too much. I am going to describe how to build a very low power FM transmitter. Do not expect this to cover the entire country, an atoll or even an island - it surely will not. However, it will be able to transmit around a block (maybe more with a good antenna) which is more than enough to tread into the world of radio and let yourself be heard.

Notes on construction:
- You need basic familiarity with electronics to undertake this project. If you studied GCE O' level Physics (or A? level Physics) then you should be familiar with the basic knowledge to go ahead with the construction.
- You can build this using a variety of construction techniques. The preferred method would be using strip board or perf board however point to point wiring would work too. Have a look here for a quick intro to circuit construction methods. Strip boards ARE available in Male'.
- The components given below can be interchanged for a equivalent and values can be approximated. So go ahead and scrounge around broken electronic items for the required components - chances are you will find most of them in broken TVs, Radios and even some toys.

- 100 Ohm resistor ( brown black brown )
- 100k Ohm resistor ( brown black yellow )
- 15pF ceramic disc capacitor
- 5pF ceramic disc capacitor
- .001uF ceramic disc capacitor
- 1uF electrolytic capacitor
- BC548 or BC108 or equivalent transistor
- Length of insulated copper wire
- Two 1.5 Volt AA size batteries
- Audio jack


Circuit diagram for FM transmitter

The tuning coil used is a length of the insulated copper wire wound around a small pencil about 6 times. The circuit can be tuned to the broadcast FM range by adjusting the coil appropriately. Turn on a FM radio and set it to the frequency you want this circuit to transmit at. Next, try squashing and/or spacing the coil turns until it is tuned to the desired frequency.

The audio can be fed to the transmitter via a tape player, a PC or even an Ipod. All that remains is for you to make your killer radio programs and broadcast it. Have fun! ;-)

The above circuit that I built on a small piece of strip board.

Let the airwaves be free!

I am a believer that technology, when applied effectively, can be a boost to the development pace of Maldives. However, technology isn't always put to its best use in the country. For example, one of the things that the government has maintained through the years is a strict constrictive policy on broadcasting. They are proud to claim that the (government operated) Voice of Maldives is the sole radio station in the Maldives meanwhile ignoring the fact that they've denied anyone else from doing the same and thus letting the government operation reign the airwaves all this while. (This misdirection is similar to the headlines that feature on the telly and radio news about Maldivian contingents "winning" the third place in sports competitions abroad - the unspoken word here being that the competition was only participated by three countries!)

Anyway, the purpose of this control over TV/Radio broadcasts undoubtedly lies not far from the fact that they are an effective medium to educate and inform the masses. Conservative and authoritative governments often resort to imprisoning the airwaves and monitor the airwaves for anyone breaking this sacred law. The Radio Monitoring Station in Male' polices the airwaves for disruptive use of radio transmitters as well as keeping a lookout for those who dare raid the airwaves with their own content.

I agree that some degree of control over the radio spectrum is necessary and is advised. All governments do have laws that govern the use of the airwaves - primarily to let the spectrum be managed effectively so as to be of use to as many people as possible. It lets radio stations broadcast without fear of being trumped by other nearby radio stations. It lets radio stations broadcast without much interference from industrial and home use devices. Sadly, this doesn't seem to be the case in the Maldives. The sole radio operator is the government using up only a single slice of the radio spectrum leaving the rest unused. Therefore, a policy to restrict other broadcasters could not be for any other purpose than laying a grip on what is broadcasted!

The content currently on the radio is also something I deem questionable. This (government) station has been bombarding the airwaves with their line of thinking, with the limited content they deem worthy. This operation also allows for the intentional (or unintentional) spread of a single propaganda that has gripped the minds of its listeners. What the station deems unworthy or unsuitable for airtime never gets heard by the populace. Additionally, anyone who listens to radio knows that it has been dominated by more or less the same old bunch of people - I know I've heard the same voices for the last 15 years or so that I can recall! The typical content they broadcast throughout the day has been Dhivehi and Hindi songs. News feature on the hour, dictating the government news and activities. English music is scattered sparsely into the day with an additional English-only hour at sunset. Educational programs have typically been far fewer from the many "argument" heavy drama's broadcasted. All this content of course has a sizeable following - after all this is coming from the sole local station in operation and has been the only source of news about the country. Some people even like the content - after all what other choice is there? what alternative have they heard?

It might be high time that the restrictions on broadcasting be relaxed. It might be high time that the masses have access to alternate view points. It might be the time to unleash a radio spectrum full of diverse programming and content. Let it be full of music varying from Dhivehi, Hindi, English, from pop, classical, trance and even industrial! Let people have access to educational content with programs on everything from language learning to electronics! Let it be broadcasting news relevant to people and society!

Are these mere ideals? Does anyone agree with these opinions?