Cable television's current boom may have peaked, a growing number of communications experts say, and urban areas such as Washington that are not completely wired may have to settle for less extravagant cable systems than they might have won a few years ago.

The combination of a tight economy, new communications technologies and an increasingly hostile regulatory climate, these experts say, are beginning to erode what was once a national cable monopoly over pay-TV entertainment services. Some of the nation's biggest cable firms already have put brakes on their expansion, insisting that their present franchises be completed before they bid on any additional cable projects.

"Cable companies are starting to realize that there's a window of opportunity for building cable systems, and it's not a very big window," says Jonathan P. Miller, managing editor of Communications Daily, a leading trade journal. "If local governments don't get themselves wired up quick, they're going to find that the window has been slammed shut on their fingers."

"The fact is that the bloom is off the rose," agrees Robert L. Schmidt, a former president of the National Cable Television Association. "Cable operators are pulling back."

Many cable company officials and financial houses that raise funds for the industry dispute this analysis and say that cable is not threatened by the recent developments. "Obviously there is competition to cable," says Bruce Burnham, vice president of market development for Cox Cable, the nation's fourth-largest cable operator. "Still, our feeling is that it's the right business to be in, and we're still going 90 miles an hour."

Cable is indeed moving at a rapid rate elsewhere in the nation. Almost 30 percent of American households with television sets now subscribe to cable, with many of them paying up to $25 to $30 monthly for the service. In addition, cable companies have committed themselves to serving another 25 million homes during the next 10 years at an estimated cost of $10.8 billion.

But the danger for communities such as the District and Fairfax and Montgomery counties, which have yet to award cable franchises, is that competition from a growing array of alternate TV services, coupled with the industry's financial commitments, will discourage some cable firms from entering their boundaries. The net result, say some local officials, is that some localities may not be able to get the cable systems they once envisioned.

"I'm afraid we'll probably have to go with a stripped-down system," says Fairfax Supervisor Audrey Moore. "I don't want to go with one of those promise-the-moon deals."

Cable TV development in the Washington metropolitan area for years has lagged far behind the rest of the nation. Washington currently ranks 22nd among the nation's top 25 television markets in terms of cable penetration, and two cable competitors, Super TV of McLean and Marquee Television Network of Rockville, have almost as many subscribers here as all the area's cable systems combined.

As elsewhere, Washington consumers not yet served by cable are turning to an alphabet soup of alternate television services. Among them:

Subscription television (STV), which beams scrambled UHF signals to the home. It is offered locally by Super TV;

Multi-point distribution services (MDS), which transmit programming via microwaves. Washington's Marquee is a microwave system;

Satellite master antenna TV systems (SMATVs) that enable big apartment complexes to pick up programming off communications satellites through the use of huge, dish-shaped antennas.

Within a few years direct broadcast satellites (DBS)--high-power satellites--are expected to start beaming programming straight to the home, bypassing cable and even local television stations.

While none of these services now offer the diversity that cable systems boast, they do promise what consumers seem to want most: sports and movies. A recent industry study found that most cable subscribers would be satisfied with only five additional channels, or far less than are offered by most modern cable systems.

And because the competing TV technologies send their signals through the air rather than over expensive cables, their subscribers can be hooked up for a fraction of the cost that cable systems face.

"People are tired of waiting for cable, so they subscribe to our service left and right," says Ed Yoe, vice president of Marquee Television Network, which beams Home Box Office movies to about 31,000 homes and hotel rooms in the Washington area. "The longer the District waits to implement its cable system , the better we like it," says Yoe.

With some 68,000 area subscribers as of May 1, as compared with cable's 74,000, Super TV and Marquee may be on their way to skimming the cream off the local cable market. Both are concentrating heavily on the District's apartment houses and well-heeled neighborhoods, the very places cable needs to do well in order to flourish.

"The District is running into danger," says Steve Effros, executive director of the Community Antenna Television Association, a cable trade group. "If they go too far down the line and too many technologies are skimming the cream off, they won't have anything left."

Cable spokesmen publicly belittle any concerns about these developments, but it is nonetheless clear that they are feeling the pinch. National Cable Television Association President Thomas E. Wheeler has taken to warning cable operators of the increasing competition and has urged local politicians to ease demands that can add millions to a system's costs. The cable industry is being subjected to economic discrimination, Wheeler says, because its competitors are not bound by local regulations.

"The message is finally coming through that cable companies are not a money machine," Wheeler says. "I think we've finally gotten to the high board from which cable operators will look over and say, 'I don't want to dive into that wet sponge.' "

Without some relief from local demands for franchise taxes, community-access channels and the like, Wheeler predicts, cable companies will stop seeking new markets. Where they once raced hungrily to outbid each other, cable companies are increasingly reluctant to promise the lavish 200-channel systems, low rates, TV studios and other services they offered during the frenzied franchising wars of recent years. That reluctance is especially pronounced in urban markets such as the District where wiring costs may reach $100,000 a mile and the tab for the entire system is expected to reach $100 million.

"In a sense it was our fault," says Effros. "We created the hype. The cities bought the hype, and added to it by greed. Now it's becoming clear that cable is not a golden goose."

In place of the lavish systems that once were offered, the experts say, there will likely be simpler proposals with fewer frills. "If the District wants cable, they ought to get under way pretty quickly. And they'd better look closely at what demands they're loading on cable," says Henry Geller, director of a Duke University think tank and formerly the Carter administration's top communications policymaker. "If they District officials ask for too much, they may very well handicap cable and they may not get an entrepreneur willing to come forward."

Already the signs of a cable slowdown are apparent. The District, which has been actively considering cable for more than a decade, has yet to receive even a nibble of interest from a large national cable firm. Tele-Communications Inc. of Denver and Cox Cable Communications of Atlanta, two cable giants that have acquired minority interests in an untested District cable firm, acknowledge that they would not enter the District on their own.

"Frankly, the Washington market doesn't look very promising any more," says an executive of a major national cable firm who requested anonymity. "I don't know of anybody who's really drooling over it."

In Fairfax, local officials who had expected almost two dozen cable bidders were dismayed this spring to find that only two companies submitted bids. Montgomery County, as well, saw several major companies pull out of its competition. And in Prince George's County, the cable system planned by Storer Cable Communications is expected to offer less to consumers than will be found in cable systems in some other major American markets.

Elsewhere, cities such as Detroit and Chicago are having trouble getting any major cable companies to bid.

"A lot of us are tied up with construction projects," says Richard Aurelio, senior vice president of Warner Amex Cable Communications, the country's fifth-ranking cable operator. "The more we all win projects and we're committed to build them, the more we can afford to be selective. And the less apt we are to take on projects that are uneconomic."

What that means for the District, which is farther behind in its search for cable television than virtually any other major city in the nation, is that local leaders may have to discard a few of their dreams if they want to attract a cable operator, some experts say. At the very least, they say, the District's bargaining power has been sharply reduced.

"Because Washington has screwed around in getting its act together, we all may end up being the loser," says former National Cable Television Association president Schmidt, who now heads a communications firm in McLean. "All the good guys in the game have called a timeout."

Such reasoning doesn't alarm District officials, who are at least a year away from reaching a decision on the city's cable franchise. "You always get these arguments of gloom and doom," says council member Wilhemina Rolark, chairman of a subcommittee that oversees cable. "Years ago, you heard the same arguments about radio, that it would go out of business when TV came along. I think there's room enough for everybody."

What kind of services are likely to go when the going gets tough? Cable experts tick off a long list of features that have eaten into cable profits elsewhere -- services that often have been expressly requested by local officials.

Among them: systems that promise to carry up to 200 channels; cable hookups for every single home and school in a locality; multiple local television studios and mobile TV vans; TV coverage of all high school sporting events; and cable contributions to local charities and community organizations.

"Those kinds of things should be left to the marketplace," says Robert L. Johnson, president of District Cablevision Inc., a minority-owned cable company in Washington. "You have to remember that cable is a business, not a social service agency."

A locality may be better off financially if it goes without some of these features, the experts say, since the system's subscribers ultimately must bear their cost. "Settling for a little bit less is probably in everyone's interest," says Richard Neustadt, a Washington lawyer who served as one of the Carter administration's top communications policymakers. "If this were boom time and we could get people to bid into the science fiction level, we'd probably only be winning ourselves the privilege of paying off a lot of bank loans."

Even Montgomery and Fairfax counties, which plan to award their franchises within a few months, don't have any guarantee that their franchises will be able to deliver everything they promise. "It doesn't matter what you're promised," says Fairfax Supervisor Moore. "What matters is the economics of the situation, and you can't control that."

In neighboring Arlington and Alexandria, local officials have first-hand experience with the frustrations that accompany changing economic times. Arlington Telecommunications Corp. promised extensive local programming when it won the county's franchise in the early 1970s, but then pleaded financial problems for years before providing the promised services. Alexandria's locally owned cable system was sold last year to The Tribune Co., the giant media company that owns the Chicago Tribune, after its original owners said economic problems endangering their system.

Wary of finding themselves caught in the same trap, several Fairfax supervisors have criticized the county's two bidders, Media General Inc. and Fairfax Telecommunications, Inc., saying their proposals are too ambitious in light of the current economic situation. "I don't see how they can possibly provide the services they're talking about at their proposed rates, given what they are promising," says Supervisor Thomas M. Davis III, maintaining neither company can lay wires through the county as fast as they say they can. "These people are basing their estimates on numbers that aren't there."

Both companies insist they can deliver what they promise, and the county has said that it will make a decision about the franchise award June 28.

In the long run, does it really matter whether the Washington area gets its television programs via the cable or by some other means? "Without a cable system, we would lose all the nonentertainment services" that cable can provide, says Sue Buske, executive director of the National Federation of Local Cable Programmers. "Things like local access programming, the ability to transport data by wire, home security, shopping and banking at home--all that stuff isn't entertainment, but a cable system could provide it."

"I don't see what you need all those channels for," says Stanley S. Hubbard, of Hubbard Broadcasting Inc., whose Minnesota firm is among eight companies bidding for Federal Communications Commission approval of its plans for direct broadcast satellites. "All people want is 12 to 15 channels of programming, and if they can get it without a cable, why not?"