Fifteen years ago Jim McDonald and Charles Schrider opened an antique store called the Drum Maker across from the train tracks on Kensington's East Howard Avenue, then a rundown strip of mom and pop stores, offices and building supply companies.

"Everybody said, 'Those guys will never make it,'" McDonald recalls, "but when we did everyone began to copy us." Today, upward of 60 antique shops fill the renovated buildings and warehouses on Howard Avenue to the east and west of Connecticut Avenue.

"We everntually moved to larger quarters on the west side," McDonald explained, "and renamed our place the Kensington Flea Market. We carried everything from rickshaws to coffins to wicker before it was popular. We used slogans like 'deliberately different' and advertised as though we were on Antique Row when, in fact, we were the only antique dealer there."

Their strategy worked, bringing buyers from as far as New York. McDonald and Schrider have now gone on to other pursuits but they left behind a wave of shop owners lured by the Flea Market's success and by Howard Avenue's ample space, low rents and location one mile north of the Beltway.

Helen Bachschmid operated a consignment shop called Good as New in Kensington from 1955 to 1967. She thinks the popularity fo Newmarket, a cluster of antique stores near Frederick, Md., influenced the growth of Howard Avenue's Antique Row. Most people, she points out, are more apt to travel some distance to visit a group of shops rather than just one or two.

Both sides of Howard Avenue - the east and the west - offer the shopper a variety of collector's items and bric-a-brac at a variety of prices. The east side has been neatly renovated and landscaped but West Howard Avenue is an unprententious jumble of old warehouses and stores trading in everything from plumbing parts to antiques.

Some of the warehouses used to hold shipments arriving on the freight trains passing through Kensington. One at 4233 Howard Ave. once was filled with sink tops, but today its huge, drafty rooms hold row upon row of old furniture imported from England by Antique Wholesalers, Inc.

The warehouse at 4229 has been coverted into booths for about 18 dealers selling everything from Oriental antiques to old silver, English china, tin soldiers and country furniture. At Susan and Sons, side chairs and rockers dangle from the rafters and the floor space is packed with spool chests, carousel animals, Maxfield Parrish prints and wicker loveseats, prams, tables and high chairs.

Owner Sue Jones, president of the Kensington Antique Dealers Association, prefers the "warehouse" side of the avenue. "I have a large inventory and I need the space. Besides, I like the atmosphere over here." Despite some minor inconveniences like a lack of sidewalks and haphazard parking on steep hillsides, Jones says her side attracts a lot of business.

East Howard Avenue is an orderly collection of tidy, small shops located between a community of old Victorian houses and the railroad tracks, now concealed by a brick wall. Until the early 1970s this was a down-at-the-hells commercial area, the site of small office operations, a laundry, local Democratic headquarters, a DGS grocery store and three or four antique stores. Except for the century-old Kensington Department Store and a half dozen other businesses, these disappeared with the area's renovation.

Most of the renovation has been done by developer Morris Parker, who bought up acluster of five buildings that dated from the 1920s. He transformed them into Antique Village, which houses about 30 of the 40 antique stores on the east side.

One of Parker's neighbors, Ed King, who opened King's Things in the mid-1960s, says Parker "changed things signifings in the mid-1960s, says Parker "changed things significantly. He brought in new business and improved the town."

"The area was pretty rank," says Parker, who used to operate a heating and air conditioning company in one of the building he now owns. "But there was a little antique jewelry store in one of my buildings and when she (the owner) left, another dealer wanted to rent the space. It just mushroomed."

Parker modernized the buildings, faced them all with brick, added bay windows and "wrought iron" grill work and connected them by enclosed hallways or brick sidewalks. He says his property is now worth $1.2 million.

Parker, who says he can "take or leave" antiques, is in the process of adding a tea room to his complex. "I can see the whole finished project in my mind. I want shops that are clean and neat, that make the customers feel comfortable. I had seen a lot of antique stores that were dirty and klutzy." He describes Antique Village as a maze of stores and says "women like to find bargains in the furthest nooks and crannies."

Aside from six or seven shop owners on Howard Avenue, most operate their businesses as a source of second income or as a "glorified hobby", as Edith Chappalear, who has run Chevy Chase Antiques since 1969, puts it.

Sue Jones of Susan and Sons says she could support herself but not her family of five on her shop's business. "If I really wanted to make money, i would do it differently. You have to work a lot harder."

Many dealers say the most successful are those who enter group antique shows, advertise heavily and cultivate their customers.

Mary Hallett, who was a co-manager of Karelia Antique Village during 1973-74, said her shop did its best business when "dealers from Texas or California would come in and buy 15 or 20 items all at once." She found business often slow, "even when hordes came through at Christmas and the weekends." Their sales increased when they started selling locally made pottery, plants and handmade pillows.

No records have been kept on how many shops have opened and folded on Howard Avenue, but Edith Chappalear thinks the turnover has been "terrific because people don't make money." She chalks this up to a lack of experience of many people entertaining the business.

Morris Parker claims that the shops in his complex are doing well and that the rare closings are usually due to personal reasons like "broken marriages." He does require dealers renting his spaces to have had "some experience" in the antique business.

Despite the varied fortunes of the inhabitants of Antique Row, new dealers keep coming. Has the saturation point been reached? "Maybe we are beginning to take away a little business from one another," says Ed King, "but I've found the other dealers very cooperative and friendly. We advertise together and send each other customers."

The proliferation of shops means that there is something for almost everyone, from the browser to the serious collector. Shoppers can find Nixon campaign buttons (25 cents), a 200-year-old embroidered Mandarin coat, cabinets from an English apothecary, signed Shaker furniture, an elaborate stage costume from the 1880s, blue and white china bird feeders, old and new dollhouse furniture and an empty box of Quaker Puffed Wheat with Shirley Temple's picture on it.

A shop called Nature's Exotics claims to have the oldest antiques in Kensington. They sell petrified mammal dung - it's 57 million years old.