Nowadays, we think Howard Stern is dangerous radio. Used to be, the radio itself was shocking.

Back when parts of New York City were still powered by direct current (DC), plug-in radios ran on the temperamental juice, which often surprised listeners more than an "Amos 'n' Andy" routine.

"Hey, Ma, it's time for CharlieMcCar [Zap!] . . . Yeoww!"

Then, during the '30s and '40s, some small radios were housed in metal cases, which could prompt a nasty 110-volt jolt.

The truth is, the idea of radio has changed very little since Marconi tapped out the first "dot-dot-dot" that signified the letter "S" in Morse code in 1901 and sent it across the Atlantic Ocean. Even with today's multimillion-dollar deejays and digital audio, radio is still about a voice magically traveling through thin air and burrowing into your ear.

A good chunk of old radio technology is now on display at the Radio-Television Museum in Bowie, which opened Saturday. The museum, established by the Washington Radio History Society, landed in Bowie because the city had purchased and renovated an old farmhouse for another group that eventually backed out. It is the only museum in the Washington area devoted solely to radio and TV, and it joins a handful of similar museums around the country. (The Newseum in Arlington includes exhibits on radio as part of its wider collection.)

Radio buffs will find the place fascinating. Laypersons may be left hungry for the stories behind the tubes and wires. And, though there are a couple of early televisions--tiny screens in huge, wooden boxes--the museum focuses on radio.

The self-guided tour starts with lovingly cared-for radios dating back to a spark-gap generator--an early radio that sent Morse code--much like the one that sent the Titanic's SOS call.

Moving forward to the teens and '20s, radios went from looking like scientific instruments to household furniture, reflecting their mainstreaming into the culture. The nation went radio-crazy in the '20s: Pittsburgh's KDKA, the first radio station, came on the air. Plans for home-built radios appeared in popular magazines and Sunday newspapers. Radio buffs tuned in to the transmissions of ships at sea.

Represented in the museum are the familiar Philco "Cathedral" radios--so named because their shape mimicked a cathedral's soaring arched windows. This was the radio of FDR's fireside chats, not to mention the centerpiece of the Waltons' living room.

There are both handcrafted and hand-painted radios, decorated by guilds of women artists. There are also a couple of art deco antennas--beautifully designed wooden aerials bound with wire. Meant to improve radio signals, they also evoke the Twenties as well as any chrome cocktail shaker.

Around the museum walls are print advertisements of the times, which help place the radios in a cultural context. During the '30s, the ad buzz was about the "heterodyne" radio, which improved the sound of a broadcast through an ingenious combination of filters and oscillators. Though "heterodyne" sounds archaic and abstruse now, its use foreshadowed the American adman's love of hyping "new and improved" products with scientific-sounding words--such as the "Hydramatic" and "Dynaflow" auto transmissions of the '40s and '50s.

Such context is where the museum could use a little oomph. On display are novelty radios, bearing the likenesses of Charlie McCarthy, Hopalong Cassidy and even the Dionne quintuplets, whose birth and childhood captured the imagination of a Depression-weary nation during the '30s. These radios, however, offer only tantalizing hints of radio's singular, inexorable attachment to the American psyche.

Interpretive placards would help the casual museum visitors, who use radio only as consumers. "Here," such a sign might say, "was the sort of radio that most of the nation was listening to on Halloween, 1938, when Orson Welles and his Mercury Theatre players convinced America that it was being invaded by Mars."

This is--at least for now--a museum of things, not ideas. Even so, surprisingly, there is no mention of "War of the Worlds," the seminal radio event, or other landmark moments: The Hindenburg crash, the attack on Pearl Harbor or any of a dozen unforgettable baseball moments. Closer to home, it would be appropriate to see, for instance, a mention of WOL-AM, the soul music giant of '60s Washington.

The museum is open on Saturdays and Sundays (except holidays) from 1 to 4 p.m. It is at the corner of Mitchellville and Mount Oak roads in Bowie. Admission is free.

Sound Bite

Through last week, WETA (90.9) had received 1,350 calls, letters and e-mails protesting the station's decision to replace classical music with "Morning Edition," a National Public Radio news program. On the other hand, about 25 people called applauding the change.

The station received a handful of letters from listeners who said they would never again contribute to the station, but no corporate underwriters have pulled out, reports WETA's Michelle Kirkwood. And several potential underwriters expressed interest in signing up for time on "Morning Edition," which is public radio's biggest moneymaker.

All things considered--to borrow a phrase--it looks as though WETA has weathered the initial storm of protest over the switch as it readies for expansion of its signal in an effort to add listeners. But the show's addition to the WETA lineup also serves as a warning to WAMU (88.5), which had been the sole broadcaster of "Morning Edition" in the Washington area. Over the next few months, WAMU may respond by adding more local news in the mornings. WETA has no plans to hire a news staff, Kirkwood says.

CAPTION: Broadcasting microphones recall the past at the just-opened radio museum.

CAPTION: John McCart of Bowie, above, born in 1915, relives a part of the golden age of wireless in a display of 1920s radios, on the market when he was a child, at the Radio-Television Museum; and a display of vintage vacuum tubes.