Minus 52 gallstones, the woman lay lonely and seriously ill in the recovery room of a Pennsylvania hospital. A brother was her only relative, and he was doing research in the Amazon, where phones are still fiction.

The brother, concerned, turned for help to an American missionary who had a small radio. Wasn't there some way they could "call" the sister?

Indeed there was, thanks to a kindly gent in a Georgetown basement.

Fielding the call from Brazil on his own radio, Martin F. Oertel asked the missionary to stand by. He picked up the white phone at the right side of his workbench. After several long distance calls, all of which he paid for, Oertel located the sister. And then he "patched" brother and sister together.

So it goes - and so it has gone more than 1,000 times already this year - for the man known as W3ESO, "the voice of Olde Georgetowne." For no salary, no glory and few thanks, Martin Oertel serves as the Washington link in a radio mercy chain known as the "Halo Net."

A retired government engineer, Oertel, 63, has been at his $2,000 console just about every day for the past eight years. He relays messages. He aids accident victims. He helps find long-lost relatives. He answers queries about weather, football, Jimmy Carter and Elvis Presley. "I guess I do whatever I need to do," Oertel says.

An earthquake in Nicaragua? "Oh, yes, I was in on that." A boat accident in the Caribbean? "Yes, I was on that for days - the good news and the bad." A death in someone's family? "I've had so many I can't remember them all."

There was the time a woman in Florida decided to marry the boy next door. Her mother wanted badly to be part of the plans, but she was in a remote part of the Dominican Republic. Enter Oertel. He flipped his dials, then sat back and nodded as the women agreed that the napkins at the reception should be purple.

Then there was the time a sailor floating on a destroyer off the coast of Vietnam had become a father and didn't know it. He soon did, thanks to Oertel.

And there was the grisly time a 2-month-old Peruvian farm girl accidentally ended up in the family pigpen. She had lost both her forearms, and nearly her life, before she was rescued. Through the Halo Net and Oertel, arrangements were made to bring the girl to the U.S. for treatment.

But no halos, please, for Martin Oertel. "I'm just one," he said repeatedly one recent afternoon, "just one of a lot of hard-working people."

One might prefer an adjective like dedicated when one learns that Oertel built and maintains all his equipment himself. Or one might consider Oertel a bit crackers to have installed all six of his antennae himself - by climbing around the tiny roof of his town house.

But that's all part of the game for Oertel, as is the anonymity. Amateur radio custom dictates that each operator identify himself only by first name. Thus, "I get calls here for Mr. Martin all the time," Oertel says.

He also gets visits and postcards.Every few weeks, someone he has helped will stop by during a Washington visit to say hello. And the door to Oertel's shack is completely covered with "QSL cards," the identifying postcards one ham sends another worldwide.

Still, Oertel says he is sometimes amazed at the lack of response from people he helps. "A lot of them do tend to think of us as telephone operators," he says, shaking his head sadly.

Oertel cringes especially at the memory of one missionary formerly stationed in South America.

Oertel spent more than a year feeding the man information from other U.S. radio buffs about jobs that were about to open up in the church's stateside administrative headquarters. The man finally got one, but when he came through Washington on his way, "He didn't even call. He's off my list for sure."

But others are on it forever.

There on one wall is a framed letter from the captain of a Navy ship, thanking Oertel for his contributions to shipboard morale. ("I let them talk to their wives back home. You should have heard what they said.")

All over his workbench are other recent tributes - from his organization, that husband, a wife, a sick child. Oertel calls the writers "my people," not as if he means to own them, but with the knowledge that they shared a human experience, and often an emotional one, somewhere along the way.

Oertel has been licensed since 1933, but he did little radio work as a young man. He traveled a great deal as part of his job, and he had three daughters to help raise. "But I got into it right after I retired," Oertel said. "It does kind of grow on you."

Even as Oertel says that, he is listening to the screeches and squawks cascading from his receiver. Suddenly, there is a voice Oertel recognizes.

He slaps down the send button of his microphone with the butt of his hand. Out burst 15 seconds worth of radioese, too encoded for a layman to understand.

But the reply is unmissable. "Hey," says a scratchy voice with a Texas accent, "how you doing, Martin?"

"That guy's in Bogota, Colombia," says Oertel. "You get to know each other." As he flips his dial, scanning for another familiar voice, one can almost hear him smiling.