Groton - The great equalizer isn't death, according to Larry Garvin. It's ham radio.

The hobby, he explains, is a level playing field. An amateur radio operator could be 6 years old; the oldest operate until the day they die.

In ham circles, you can know someone for a year before you know what they do for a living, says Garvin, an active member of the area's biggest ham radio group, the Tri-City Amateur Radio Club. "That's not who you are," he says. "It's - you're a ham, period."

Amateur radio is both a hobby and, even today, an emergency management tool. Licensed operators use certain frequencies to communicate among themselves and with relief organizations during a crisis.

The region has three ham radio clubs - Tri City, Radio Amateur Society of Norwich and the Southeastern Connecticut Radio Amateur Radio System - with nearly 200 members, all unflinchingly proud of the hobby they often wear literally on their sleeves - and on their hats, shirts and vanity plates. Operators' call signs - the series of letters and numbers used as ID, the same as on any American radio station - are a favorite for this kind of display.

On a Sunday morning in June, Garvin is the first to arrive at the Submarine Force Museum. The Navy veteran once served on the Nautilus, now permanently docked just yards away. His blue eyes match his trucker hat, which can't contain several tufts of white hair.

It's day two of Museum Ships Weekend, an event headed by the Battleship New Jersey in Camden, N.J., during which hams on more than 100 restored military ships race to contact each other by radio. It's a smaller-scale version of the American Radio Relay League's annual Field Day in late June, the most popular on-air event, according to the league website, when more than 35,000 hams gather in remote locations for a 24-hour radio call marathon.

Camped out here in the parking lot beside a fully equipped, 16-foot, orange trailer, a dozen or so hams will try to pin down 15 other ships to get their certificate. They'll have to submit their call logs to the battleship by July 30 to get credit.

But that might not be the right way to phrase it.

"Credit's a strong word," Garvin says.

• • •

Hams pride themselves on extensive QSL card collections - QSL is code for confirming receipt of a radio transmission - as proof of communication between two hams, often personalized on homemade, colorful postcards. But Garvin says events like these serve two purposes: camaraderie, and honing skills for emergencies. There's much more "rag-chewing" - casual conversation - than actual competition.

"When hams get together," says Darryl DelGrosso, wearing a bucket hat filled with pins from Field Days past, "we like to talk."

DelGrosso, North Stonington's perennially suspender-clad tax assessor, who administers local amateur radio license exams, built his first radio in the 1960s. It had three frequencies, three crystals for $5 each, and a tube transmitter for $21.

Has he contacted all 50 states?

"Of course," he says. "I can do all the states in one weekend."

DelGrosso suspects there isn't a country he hasn't talked to. Maybe some Pacific Island nations. "I like to play," he offers.

It's a lifestyle that comes with its own set of jargon. A radio is a rig; hams refer to each other by their call signs; "elmering" is hams helping out other hams.

Amateur operators must be licensed by the Federal Communications Commission. After successfully passing an exam, an operator is authorized to use radios for regular and emergency communications, to experiment with different kinds of radios and frequencies, and to bolster radio use among the public.

A small handheld radio can cost as little as $50, though the higher-end ones - the radios of a ham's dreams - can cost up to $15,000.

The exam identifies level of expertise. An entry-level ham is a "technician," an intermediate is "general" class, and the highest is called an "extra."

It's sort of like buying a handgun, Garvin says. "You can't just pick up a radio."

But upon clearing that hurdle, a ham becomes part of a massive community - the ARRL estimates 710,000 licensed hams in the U.S. and 3.6 million worldwide - that comes together on the air, in clubs, at conventions and at "hamfests" - radio tag sales.

Garvin says a national convention in Hartford scheduled for July 2014 is expected to draw a crowd of 5,000 to 10,000. The big one is the Dayton (Ohio) Hamvention, held annually in May.

"Everyone says, before you die, you've got to go to Dayton," Garvin says.

For a ham, he says, nothing is more exciting than traveling to meet a longtime radio contact. They'll take photos, talk kids, grandkids, houses - not just their beloved hobby.

"It's human relationships that can last a lifetime," he says. "And it doesn't necessarily have to be the guy down the street or around the corner. It can be someone on the other side of the world."

• • •

Ham radio seems like a bit of a boys' club at first glance, with the attendant humor. The jokes abound: "ham shacks," the equipment-packed dens where hams operate, are "where your wife lets you keep your radios." A ham with a particularly pricey rig is almost certainly a bachelor, they say. And when a woman's voice comes crackling through the transceiver, she is gleefully referred to in shorthand as a "YL" - a "young lady." (A wife is "XYL.")

Sean Kutzko, the ARRL's media and public relations manager, says the predominant demographic of older white men stems back to when radio was the cutting-edge technology in the 1950s and '60s, when young men rushed out to get their licenses. A spike in the last decade among the 16- to 35-year-olds seems to be based on the do-it-yourself and "maker" movement - people interested in electronics experimenting, learning about physics, and, he says, "just because it's cool."

Women still make up a measly 4 percent of hams, he says. But they're working on it.

Garvin, who lives in Lisbon and refers to himself as a "short-wave nut," recalls idolizing his globetrotting Uncle Richard, a geologist who would tell stories about high adventure and European luminaries.

Then, Uncle Richard would turn on the radio.

As he tuned through, he would narrate who was on the air, where they were, what that country was like. The world is a big place, his uncle told him. But things like this radio box, he promised, are going to make it so much smaller.

Garvin began taking classes while working as an information technology executive at General Electric. He retired after 30 years in 1998 and became a "serious" ham.

There is plenty of reason to take the hobby seriously - times when this old communications technology isn't a relic, but a necessity. At races, civic events and parades, hams are stationed in tents and along the sidelines, reporting injuries and supply requests, maybe coordinating a ride for an exhausted marathoner. During Superstorm Sandy, hams worked with the Red Cross to report shelter conditions.

"It's not the best form of communication in this day and age," says Harry Solt of Gales Ferry, a retired Navy submariner participating in the ships event with his son, Michael, a network engineer who lives in Andover, Mass. Michael volunteered during the Boston Marathon.

But when the cable is out and the cell towers are overcrowded in a crisis, Solt says, "Radio is often the only one you have."

• • •

At five minutes to 9, the ARRL flag is hoisted above the trailer at the Nautilus parking lot.

The first crackles of static sound just before 9:30 a.m., along with some squeaky science-fiction noises as the operators cycle through the frequencies, spinning dials.

DelGrosso is the trustee for the call sign of the day: N1S, for "nuclear 1 submarine," used on all of the radios there.

Ken Rutt, 45, of Brooklyn is working his own radio, wearing his headset, his laptop logging every radio call.

"This is November one Sierra calling, CQ, 20 and listening," he says.

A voice crackles through - Roger from North Carolina.

Then it's one after another. Some a low, unintelligible rasp, like being on a bad cell connection - "I lost you in the noise there" - and with others, it's as though the operator were standing right next to you.

"Ted or Ed?" Rutt asks one operator.

Then, swinging back up north, the call is from Rob in Michigan, November 8 Delta.

"I appreciate the contact," Rutt tells him. "Thank you so much."

Rutt passes off his headset to Solt, who used to build radios with his father in the 1950s. He can still rattle off his father's call signal, K3LBD, and calls him a "silent key" - the title reverently given to dead hams, taken from the term for Morse code switching devices.

"It allows us to keep in touch in a unique way," he says.

When the day is halfway done, they have been joined by about a dozen more hams - including Buzz Page, 71, a former toolmaker and machinist for Electric Boat who lives in Groton; Mike Tucker, 68, of Montville, TriCity's president and a retired radio frequency technician; and Sal Vella, 69, of Gales Ferry, also a former EB employee.

Vella says one day he was simply fed up with paying for cable and began doing research on antennas. His newfound hobby, he says, was all Comcast's fault. Now he keeps in touch with a scientist stationed at the South Pole.

In the trailer, the younger Solt settles on the 18.130 frequency, honing in on November 5 Echo in Galveston, Texas, a ship. Clear as a bell here, but at the other end, Solt's voice fades in and out.

Finally, success: the voice of a woman named Lynn, stationed on the USS Cobia in Wisconsin.

"This is the USS Nautilus, America's first nuclear submarine and first submarine to the North Pole," Solt says.

"That is excellent," Lynn replies. She advises him that another ship is "right on top of us."

The conversation wraps up; Solt offers a typical ham phrase as a sign-off.

"We'll catch you later down the log," he says.

a.isaacs@theday.com