It has been 16 years since the first cable system came to the metropolitan Washington area, but you still can't get MTV rock videos in the District.

By the time a D.C. system is built and the rest of the metropolitan area is connected to cable, cable companies will face challenges unforeseen a decade ago: A potpourri of exotic new video technologies will compete with cable service, and cable service thefts will continue to force operators to use more complex systems.

By 1989, the National Cable Television Association estimates, all construction in the area finally will be complete, except for a few, sparsely populated pockets.

Virtually all of Northern Virginia is now wired for cable. "There are well-established systems that have been in operation for several years, so if you live in Alexandria, Arlington or Reston, cable service is available," said Steve Tuttle, managing editor of TV Digest.

"Montgomery County and Prince George's County have just been franchised in the last couple of years and are all under construction, with portions of those communities having service; Fairfax is mostly built," he said.

Rates for basic service range between $10 and $12 a month, and the systems offer varying numbers of channels with similar entertainment choices, he said.

Congress has deregulated rates cable operators can charge, except in areas where specific rate freezes are outlined in the franchise. In those areas, cable companies still are permitted to raise rates 5 percent a year, Tuttle said.

Washington just last year awarded its cable franchise to District Cablevision Inc., a private company partly owned by a combination of local shareholders, including Robert L. Johnson, president of Black Entertainment Television. The system also is owned by large multi-system cable operators Tele-Communications Inc. and United Cable and will be built by the Chesapeake & Potomac Telephone Co.

The company was told it must begin building in the next 15 months and must have the system completed by 1989.

The reason the process has taken so long boils down to politics and need, said Winfield M. Kelly Jr., who worked for Storer Communications Inc. Storer, which owns 300 cable systems in 22 states, held the franchise for the northern half of Prince George's County, but has sold it to Prime Cable of Maryland Limited Partnership Inc., a privately held company Kelly has joined.

"In the Washington area, if you wet your index finger you pick up about 14 channels with conventional TV , and there was not a great hue and cry for cable," Kelly said.

Cable was first used in the 1960s to provide conventional TV signals to rural areas. But new cable programming and satellites that could beam cable service anywhere revolutionized the business in the 1970s.

"It became the darling of Wall Street, and many companies decided to get into the industry pell mell," Kelly said. Groups of local investors formed to bid for lucrative franchises, competing with the numbers of channels they could provide.

With the frenzy came delicate political decisions. "The political process was slow so that every community could be assured they wouldn't be criticized for granting franchises for political reasons," he said. "City councils had to choose between five and six very important groups of their friends and didn't want to do that."

It also was difficult for city councils to choose between technologies. As the technologies became more advanced, they "caused some additional problems," Kelly said. For example, cable systems have been computerized to prevent theft of service, but that modification has interfered with the ability of cable customers to use videocassette recorders.

The National Cable Television Association (NCTA) estimates theft of service cost cable operators between $500 million and $700 million last year.

Cable companies are expected to make major inroads against service rip-off artists through using more sophisticated, computerized cable technologies. But consumers may have to adjust to the viewing inconveniences that some of the new "secure" technologies cause.

Theft of service, easily accomplished through buying a bootleg converter box or tampering with a box to allow reception of cable channels without payment, is subject to federal and state prosecution, said Ed Dooley, a spokesman for the NCTA.

Amnesty programs throughout the country have been set up to let people turn in their boxes without fear of prosecution, and, in San Diego alone, 130,000 tampered boxes were turned in recently, he said. Cable operators provide converter boxes to customers that regulate how many channels a customer receives. The number depends on the fee paid.

Older cable systems allow thieves to tap into many channels using tampered boxes or other devices, said Fern Krauss, a spokeswoman for Tribune-United Cable Co. in Rockville, which won the franchise to wire Montgomery County in 1983.

Newer, computerized cable systems cannot be tapped with a tampered converter box. Some systems also send fewer channels of service into the house at a time -- a drawback to customers who might want to record a program on one channel while watching another or who want the ability to watch two different shows on two different sets.

Christopher M. Young, vice president of operations for Arlington Cable Partners, which assumed the Arlington franchise originally granted to a predecessor in 1973, said he is looking at the newer computerized technology. Currently, cable outlets leading up to homes or apartments must be physically inspected for signs of theft, he said.

"We don't like that new approach because it prevents people from watching more than one program on more than one set at a time," he said. "My system works better because it is simpler." But theft of service also is easier, he added.

Cable-ready television sets, meant to eliminate the need for a converter box, also are rendered obsolete because they are not built to operate with new computerized systems.

Such problems came to the attention of the Montgomery County Council recently.

"I cannot watch one cable station and record another one," said Gail Ewing, assistant to council member Esther Gelman. "The fact that I have a cable-ready TV is just a waste of money because I have to have their converter box," she said.

Service problems, such as quality of the picture, experienced by start-up companies have for the most part been eliminated, said Ewing. The council is said to be concerned, however, that the cable technology has evolved in response to the theft problem into something different from what the council thought it was getting.

"This is a national problem faced by all cable systems," said Tribune-United's Krauss. "It is not unique to us . . . All of the cable operators are looking toward securing their systems and programming signals."

One advantage of the newer computerized technology, however, is lower maintenance costs to cable operators. Because the equipment is computerized and often located on utility poles, customers need not be inconvenienced by service calls, said John Schmuhl, vice president and general manager of Tribune-United.

Creating "confidence that their property will be treated well" also is crucial, he said. The cable company assumes all responsibility for leaving backyards the way they were found, repairing the damage from ripping up the yard to install cable, he said.

Cable faces stiff competition from regular television provided free of charge and videocassette recorders, which allow would-be customers to simply buy or rent a tape of a movie instead of subscribing to cable service.

"Viewers are becoming their own programmers," said NCTA's Dooley. "They are choosing from a wide array of program services that come to them directly from the satellites, from scrambled over-the-air signals, from microwave services and, of course, videocassette recorders and cable," he said.

"The pattern nationwide has been these systems alternatives to cable usually are viable until cable comes to town," said TV Digest's Tuttle. "Instead of getting one or four channels for $20 you can get 40 or 79 channels for the same $20."

Still, Prime Cable's Kelly said he expects cable to be so firmly entrenched by the 1990s that it will be "even more competitive" because of its large market share.

"The question for the consumer is what is the most cost-efficient and exciting service, and that's what we are going to find out," said NCTA's Dooley.