SEOUL, South Korea (CNN) -- It broadcasts only three hours a day. Its on-air reporters use fake names. And its operators don't know for sure whether their target audience is listening.

Kim Seong Min, the founder of Free North Korea Radio, broadcasting from Seoul.

Free North Korea Radio, based in Seoul, South Korea, broadcasts news of the outside world across the border. It's illegal for North Koreans to listen to anything other than state-run radio, and all legal radios are fixed so they can play only channels approved by the government. But the founder of Free North Korea Radio, Kim Seong Min, believes that more and more North Koreans are secretly tuning in.

Kim is also a defector. A former propagandist for the North Korean army, Kim says he collected an illegal radio on one of his patrols. He was curious, so he tuned in to a South Korean broadcast.

The program centered on the leader of North Korea, Kim Jong Il. He says it was meant to dispel the myths surrounding the leader, including the story of Kim Jong Il's birth. North Koreans were taught to believe that Kim Jong Il was born on Mount Paekdu, considered sacred in Korean history. But the radio program Kim heard that day said Kim Jong Il was born in the Soviet Union. Kim started to doubt everything he was taught to believe, and the more he listened, the more he was convinced that he had to leave the country.

In 1996, Kim says he made a perilous escape by crossing the North Korean-Chinese border, only to be caught by North Korean soldiers while trying to board a ship to South Korea. He was sent back to North Korea but escaped once again by jumping off a train.

For days, Kim says, he hid in the Chinese countryside, eating roots and grass to survive before finally settling in a nearby town. Three years later, he says he made his way to South Korea, where he started Free North Korea Radio in 2004.

"North Koreans need food, but they also need food for their minds, otherwise they will continue to have deformed children, and they will be people with deformed minds," Kim said.

The radio program is three hours, but Kim hopes to expand to five hours daily, broadcasting during the evenings and late at night, when he believes that most North Koreans are able to tune in. But running a radio station is expensive, and FNK Radio relies on donations from South Korean citizens as well as an annual grant indirectly from Washington, through the National Endowment for Democracy.

Though funding is sometimes a struggle, they believe that the broadcast is vital to North Korea because the South Korean government stopped its own radio broadcasts into the country under the "Sunshine Policy" instituted by former President Kim Dae Jung in 1988.

Kim Seong Min is the only North Korean on staff at the radio station who uses his real name. Three of the 15 staffers at FNK Radio are South Korean; the rest are defectors. They use pseudonyms to protect their families who are still living in the North.

One defector who calls himself Kim Dae Sung says he bought a radio on the black market and listened under the covers at night. He didn't want to risk being heard by his family or any neighbors, because they would be required by law to report him to the police.

Kim Dae Sung says that although he was nervous about listening to the radio illegally, he also looked forward every night to being able to hear news of the outside world. He also says he began to realize that everything he was taught was a lie and decided to escape.

He believes that the work he does at FNK radio is helping other North Koreans hear the truth about the world.

"My family is important, but what I'm doing here at the radio station is even more important," he said.

There's no way to determine how many North Koreans are actually listening to FNK Radio, but Kim Seong Min says he receives letters and phone calls almost daily from defectors who say they were able to hear his program through radios bought on the black market.

"When we started, I thought, if just one person, just one North Korean was listening, that would be good enough," Kim said. "But it's not just one person."

Kim believes the North Koreans try to jam their radio signal into North Korea, and says the North Koreans have called him a traitor. If he were ever to go back to his homeland, Kim says, he would receive "the highest punishment" for his work. But he and the other staffers at FNK Radio all believe that it is worth the risk.

That's why, when they receive the messages from defectors, Kim says, they often grab each other and cry. E-mail to a friend