A Washington entrepreneur has been ordered to pay more than $100,000 in damages for selling rooftop antennas that can intercept pay-television signals. The judgment is believed to be the largest awarded in a pay-TV "piracy" case.

The ruling against William Early, owner of AIDA TV Sales and Service on Florida Avenue NW, is a major victory for pay-television broadcasters, who distribute Home Box Office, Showtime, Movie Channel and other programming, in their campaign to stop pay-TV pirates from tapping into their services.

More than 25 state and federal court rulings handed down in the last year have held that it is illegal to sell or use microwave receivers designed to pick up the signals of pay-TV distributors.

In the local case, a federal judge two weeks ago ordered Early to pay $102,375 in damages to Marquee HBO in Rockville, a local distributor of Home Box Office, a Time Inc. subsidiary that sells commercial-free prime movies, exclusive concerns and drama to subscribers for a monthly fee.

Early, along with other makers or sellers of the microwave receivers, say they are doing nothing wrong, because these microwave signals are broadcast everywhere and are unscrambled.

"My contention is that, if you don't want me to receive the signal, then keep it out of my bedroom," Early said this week. The $102,375 judgment against him would "put me out of business three times over," he added, saying he plans to appeal the federal district court's decision.

Most of the decisions have been based on Section 605 of the Federal Communications Act, passed in 1934, which makes it illegal to intercept a radio signal on an unauthorized basis.

Home Box Office is provided to 35,000 Washington area subscribers over microwaves transmitted from Marquee's towers to subscribers' roof tops. Customers pay an installation fee and $14.95 a month for a microwave antenna and converter.

Hoping to profit from the demand for the inexpensive, easy-to-build antennas, a number of distributors sprang up here two to three years ago. Last year, before a federal judge issued a permanent injunction against him, Early sold more than 60 of his antenna systems for $375, including installation.

The devices also could be ordered by mail for between $150 to $250. Despite the recent flurry of court rulings that the sale and use of the antennas is illegal, advertisements offering them for sale can still be found in a number of magazines. Two appeared in the August issue of Popular Science.

Marquee began its fight against "video bandits" last May when it hired investigators to track down sellers of the antenna equipment and to compile lists of homes with unauthorized microwave receivers on their roofs, according to Steven Wechsler, executive vice president.Names also were compiled from advertisements by the distributors, both in newspapers and by flyers.