At the top of the Washington Monument, a telephone is ringing. It may be the death knell of what, if anything, remains of civilization in this city.

In a year or so the phone may be ringing up there all the time, not to mention in saunas, golf carts, hot air balloons, the middle of fox hunts, lovemaking, tennis and whatever else you may have done believing that you were safe from ringing phones.

The reason is the Motorola Dyna T-A-C portable radio telephone system, one pound and 12 ounces of ultra-high frequency cellular system radio that is now being test-marketed to 100 selected customers in the Baltimore-Washington area who can afford the $190-a-month rental.

It doesn't work like a radio, though. No "overs" or "10-4s" or any of that. It works like a phone, with simultaneous two-way transmission, "duplex" as they say in the trade. With the aerial sticking out the top, it looks like a very small walkie-talkie.

"Your phone is ringing," says Suzanne Klein of Oklahoma City, turning away from a fine view of a brown winter Mall and a white Capitol at the sound of it, which is cheery as morning's own little bluebird.

"Mr. Watson, come here, I want you," says the guy carrying the phone when he answers it -- that line being Alexander Graham Bell's first words on his first phone. Legend has it that Bell wouldn't have one in his house because life would be hell if people could just call you all the time.

"Hey, can I call my husband in Oklahoma City?" says Klein, when the conversation is over. She can and does, passing on the information that she'll be taking a later plane home. People stop. People stare.

"It ain't got no wires!" shouts Steve Cotov of San Diego.

The guy who brought it up here calls literary agent Esther Newberg in New York. Newberg talks on telephones the way Heifetz plays violins. Nevertheless, she is appalled.

"The top of the Washington Monument?" she says. "Do you realize how dangerous that is?"


"If you can start getting phone calls anywhere, all the Type A personalities in the world will be having heart attacks at the age of 31," says Newberg.

And, in the words of an official at the American Radio Telephone Service in Baltimore, which is running the test marketing, along with Motorola: "The demand for mobile service, because of the very nature of the Washington community, is as great as any place in the country. There are a tremendous number of very mobile people in Washington, and people are very communications conscious."

The system works by having seven "cell sites," in Virginia and Maryland, which send and receive signals from the handsets and relay them to another station in Columbia, Md., which puts the signal into the telephone system's wiring. The hand-held set can be operated in an area from Leesburg to Mount Airy to the Chesapeake Bay to Springfield, Va., to Lutherville, Md., miles north of Baltimore. Just pick it up and punch in your number.

"From the Washington Monument?" says John Rolfe Gardiner, a New Yorker short story writer who lives in Unison, Va. Gardiner is a man who casts a cold eye on this sort of thing. "How big is it?"

He is told that it would fit in a pocket.

"Your hip pocket, no doubt," he says.

(A jacket pocket would do, with the antenna unscrewed.)

"Hey, can I call my relatives in South Dakota?" says a man on the lawn sloping down from the monument.

This is only the first of many problems presented by this phone: phone moochers. Hey, I gotta call my girlfriend. Hey, you mind if I find out what the weather is . . . (It's 44 degrees -- 7 Celsius -- at National Airport, as it happens, the barometer 30.01 inches and falling. And the stock market at 12:15 is down 5.62, according to a local broker who is contacted from the middle of traffic, down by the Ellipse.)

These phones will destroy beepers as status symbols. No longer will Georgetown dinner parties sound like swamps in the spring, all that beeping for Big Guys to call their answering services. No, it'll be worse. Everybody at the table will be talking on the phone while the fettuccine Alfredo cools. Some of them, no doubt, will be talking to each other.

It will become a prime test of marital fidelity: "Would you mind explaining why your phone was turned off for two hours and 17 minutes this afternoon?"

People won't be able to have themselves paged in restaurants anymore -- they'll be carrying phones, and no one will be calling them.

The possibilities for reviving the old past-posting game at the race track are stunning -- you may have noticed a scarcity of telephones in sight of the finish line.

Downtown Washington will look as if it's guarded by thousands of Secret Service agents, with all these men in business suits talking into little boxes with aerials.

Nevertheless: "It's fantastic, without a doubt," says Jorge Carnicero, a marketing representative for Dynalectron, an electronic security firm in McLean. "When I first took delivery I was amazed, I couldn't believe it."

"I think it's terrific," says Bill Devries, head of the Honor Guard Security Services. "It's a great gimmick for sales -- it gets peoples' attention. It's a source of power. When I drive to work in the morning, it just kills me not to be able to communicate. Now I can."

There are the Japanese to be reckoned with, of course. They already have systems in place in Tokyo, Osaka and Nagoya, according to Stuart Crump, who puts out "Cellular Radio News."

But Motorola is confident. "We think we can beat the Japanese," says Norman Bach, an engineer in Motorola's K Street office.

Other American companies are interested in the field. The Federal Communications Commission has divided the available frequencies, half for radio companies and half for wire companies -- the phone company.

Millicom Inc. in New York plans to sue when this ruling becomes official. President Peter Erb says Millicom can deliver better service for a third the cost, and is planning a test in the Raleigh-Durham, N.C., area this spring. He disputes Motorola's predictions of 1.5 million units being in use by 1990. "We're talking about 50 to 60 million over the next 20 to 30 years."

Phones ringing everywhere! A miracle! Frightening! Think how powerful the telephone is already-- it's about the only thing that will pry most Americans away from a television, for instance. We all jump for a ringing phone.

So it's reassuring when a call is placed to a woman in Takoma Park.

"I'm calling from the top of the Washington Monument! Call me back!" says the caller.

"No way. I've got the kids in the tub," says the woman with a contempt for progress that seems particularly healthy, in the age of the pocket telephone.