Mark Sapp, left, and Jeff Nelson, both of Baltimore Hackerspace, attempt to get a test signal on an old oscilloscope during the Techno-Swap-Fest at the National Electronics Museum in Linthicum, Md. (John Kelly/The Washington Post)

Do you find resistors irresistible?

Do you see the potential in potentiometers?

Do you have the capacity to love capacitors?

Then you should have spent Saturday morning where I did: at the National Electronics Museum’s annual Techno-Swap-Fest.

“I have no idea what 99 percent of that stuff is,” said Mike Simons, director of the museum, which is in Linthicum, Md., not far from BWI Airport.

Jason Robb of Glen Burnie, Md., had remote-controlled cars and helicopters and parts for sale at the Techno-Swap-Fest. Vendors rent tables to sell old electronics equipment. (John Kelly/The Washington Post)

Arranged in a large hall at the back of the private, nonprofit museum were 46 tables covered with resistors, potentiometers, capacitors, wires, wire nuts, wire markers, vacuum tubes and VU meters.

There were cooling fans and heat sinks plucked from the backs of broken computers, numbered dials yanked from the fronts of old TV sets, and motors salvaged from milling machines. There were dismembered recording studio mixing boards and homemade Heathkit stereo amplifiers, scratched and dented but still in working order.

John Carpenter sat behind a table and ticked off some of the items atop it: “That’s a relay. That’s double-sided tape for wrapping wire. That’s an old tach dwell meter. That’s a servo motor. That’s an IR distance sensor.”

And what might one do with an IR — infrared — distance sensor?

“It’s good if you were doing a little home robot,” said John’s son, Michael.

The room was full of the sort of people who might be “doing a little home robot” or working on some other nifty project involving old stuff. We’re in the midst of the “maker movement,” where hackers marry the ancient to the modern.

I listened as an older man from Columbia, Md., described how he was going to take a 1933 Philco cathedral-style radio console, outfit it with a tiny Raspberry Pi computer and turn it into a player for streaming audio.

Jack Warner of Cheverly, Md., with some old computers and radios he was selling at the Techno-Swap-Fest. (John Kelly/The Washington Post)

“It’ll sound better, look old, and I’ll be the first on my block to have one,” he said.

Jack Warner of Cheverly, Md., was selling an array of things, from a pair of Radio Shack TRS-80 Model 100 laptops — $200, including acoustic coupler and cassette tape drive to load programs — to an old transistor radio priced at five bucks.

“My mother used that to listen to Paul Harvey,” Jack said of the radio. “He’s dead. She’s dead.”

Jack was also selling his Fisher 500 amplifier-receiver, a handsome assemblage of wood and brushed metal and the very radio he used to pull in WQXR when he was a student at Rensselaer Polytechnic Institute in the 1950s.

“I was a geek,” said Jack, 78, “a happy geek.”

Craig Cole of Ellicott City, Md., bought Jack’s old computer setup, with the TRS 80 proto-laptops, known to a generation of journalists as “Trash 80s.”

“I couldn’t help myself,” said Craig, 46, a software developer for the Howard County government. “I don’t know when I’ll have a chance to play with them, but I couldn’t pass them up.”

Why would anyone want computers that possess barely more memory than those greeting cards that play a little tune when you open them?

For the satisfaction, Craig said, of “figuring out how to make old stuff relevant.”

(Full disclosure: My Lovely Wife is on a committee that’s working on a new gallery at the museum that will be devoted to satellites, the industry she works in.)

Frank Pittelli of Annapolis, Md., started the annual swap meet seven years ago. As an adult, he’s founded three software companies. As a youngster, he tinkered. He’d like to see more young people doing that.

“Over the years, what’s happened is the younger generation has shifted focus mostly to electronics, mostly to computers, mostly to software,” he said. “My belief is they’re still intrigued by the real world.”

The real world is more than antiseptic zeroes and ones. It’s a world where vacuum tubes glow when a current passes through them, casting off a warm, dusty smell. It’s a world of dials that you spin and needles that move, of gears that engage. It’s a pleasantly tactile world.

The Techno-Swap-Fest brought together multiple generations of tinkerers. There were old guys carrying canvas tote bags embroidered with their ham radio call signs and young guys in tight jeans and hipster beards. In a museum classroom, a half-dozen elementary school-aged kids were being taught how to solder. Solder!

Frank estimated that of the items purchased at the swap meet, a third would be used as intended; a third would be gutted so the retro-styled case could be repurposed; and a third would be placed on a shelf, an object just to be looked at and admired.

He said people especially like old oscilloscopes, those science-fictionesque cathode-ray tubes that display sinuous waves of acid green.

“It just looks neat,” Frank said.

He got no argument from me.

Twitter: @johnkelly

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