If you thought radio was dead and defunct other than in the government-run and commercial sectors, then electrical engineer Arun Mehta has some unusual lessons to teach.

Delhi-based Mehta, 52, an engineer-activist educated at the Indian Institute of Technology (IIT) and earlier active with Amnesty India, says: "We are indeed looking at the innovative uses of low-powered FM."

This ranges from using radio for cheap simultaneous translation to cutting down on noise pollution and taking information to villagers.

Mehta, who is chief technical officer at the cyber-based radiophony.com network, says it is possible to build a simple, low-powered community radio station for under Rs.1,000 ($25).

Mehta told: "In India, 50 milliwatt FM transmitters are commonly available in the market (for commercial purposes from cordless mikes to children's toys). We assume the use of this is legal.

"So we set up a 50 milliwatt transmitter in Oravakal village in Kurnool district of Andhra Pradesh."

His group deployed a low-powered radio for simultaneous translation. "At the Asian Social Forum in Hyderabad in 2003, we did simultaneous translation for more than 8,000 people in three languages - Telugu, Hindu and English," explains Mehta.

They put up three low-powered FM radio transmitters in each hall, one for each language, and all set to broadcast at different frequencies.

Participants were given tiny and inexpensive made-in-China FM radios, with earphones. Each participant tuned the radio to his or her language's frequency.

"So basically, this was simultaneous translation for under one-dollar per participant," he says.

In another case, he showed how low-powered FM could also keep down noise pollution. He calls it "concerts without noise pollution" and it uses a concept of distributed-sound.

Mehta explains: "Rather than having one large set of speakers, what we do is feed the audio to a low-powered FM transmitter. Then we place radios where the people are actually sitting."

This was tried out at the Ban Ganga festival held near Malabar Hill in Mumbai in January each year. Earlier, organisers were being compelled to cancel the event, due to the noise it generated.

This work is gaining attention. "We've demoed this at events like Asia Source (an international event for NGOs held in Bangalore in early 2005), Radiocracy in Cardiff (Wales) around 2000, and at Africa Source II held in Uganda recently," says Mehta.

"This is very simple and inexpensive technology. The parts that go into the low-powered transmitter cost under $2. The parts are available in any small town where radios and TVs are repaired."

But Mehta is upset that the airwaves aren't being productively used. He says: "In India we have the most absurd system for management of spectrum. Anything above one milliwatt requires a licence. There are only two exceptions - certain kinds of cordless telephones, and the other is 2.4-gigahertz wifi," Mehta adds.

"In rural India, you're not able to take wires to people's homes. You need wireless," he explains.

He feels rather than auctioning or allocating spectrum to favourite projects, the government should opt for an "open spectrum" policy.

"What governments can do under open spectrum is to lay down rules for social behaviour - ensuring that you maintain low power levels, that you don't hog any segment of the spectrum. It's the basic rules for wifi," says Mehta.

Recently, highlighted the story of a young man from Bihar, who runs a tiny "radio station" set up at a low cost in Mansoorpur village in Bihar's Muzaffarabad district. Mehta's radiophony.com site offers plans to build transmitters at low cost, as do many other sites on the Internet.