DISNEY CHANNEL TO START NEXT WEEK; BY SALLY BEDELL

Next week, Walt Disney Productions will stop wishing upon a star and begin wishing upon a satellite. On April 18 the company that made its name on wholesome films, prime-time series and theme parks will test the allure of its cleancut philosophy in a new arena, cable television, with the Disney Channel. The channel, a 16-hour-a-day collection of Disney classics such as ''Dumbo'' and $45 million worth of new programs, will be beamed by satellite to cable subscribers around the country.

The service is intended for viewers who are ''disenfranchised from the main thrust of mass culture,'' said James P. Jimirro, president of the Disney Channel, in his office overlooking the sunny San Fernando Valley. Those viewers, in Mr. Jimirro's view, are families turned off by what he described as ''the repetitiveness and low mental level'' of network television and by the proliferation of Rrated motion pictures in neighborhood theaters.

Views on the Prospects

With its reliance on the Disney name, a vast library of films and cartoons not available elsewhere on television, and an investment of more than $100 million in new programs over the next three years, the channel is regarded by many industry experts as the most promising program-service in cable television in recent years.

But the Disney Channel arrives at an unsettled time in cable programming. It follows the recent failures of CBS Cable, a cultural service that lost more than $30 million; and the Entertainment Channel, featuring quality films, series and plays, which lost more than $50 million. Consequently, some analysts wonder whether the Disney Channel has a wide enough appeal - to adults as well as children -for cable subscribers to pay $8 to $11 extra a month to receive it.

''Will there be enough families with children to go for it? The answer is probably yes,'' said Paul Kagan, a cable-industry analyst. ''Whether there are enough adults without children depends on the quality of their feature films.''

The Disney Channel will initially be available to 4 million subscribers in nearly 400 cable systems around the country. So far neither Manhattan Cable or Group W Cable, the two services in New York City, has agreed to offer the channel, although cable companies in Lynbrook, L.I., and Haverstraw, N.Y., have picked it up. Viewer Total Unknown

Disney officials were unable to estimate how many actual cable viewers had signed up so far. Mr. Jimirro said that one cable owner, Tele-Communications Inc., had received 21,000 orders for the Disney Channel on its 175 systems around the country.

''That seems pretty doggone good after one week of selling,'' said Mr. Jimirro, a genial enthusiast of the Disney cause. Mr. Jimirro said he anticipated having 500,000 subscribers by the end of this year and close to 2 million at the end of 1984, when the channel is projected to begin making a profit.

The principal lure for viewers, according to company officials, will be the traditional Disney fare. Many of these programs have been buried in Disney vaults for decades. However, with a few exceptions, such as ''Alice in Wonderland'' and ''Mary Poppins'' 15 of the most popular films - including ''Fantasia,'' ''Snow White,'' ''Bambi'' and ''Lady and the Tramp'' - will not appear. The reason, Disney officials say, is to avoid home taping by viewers on video-cassette recorders.

Planners at the channel are also counting on the nostalgic appeal of old cartoons and television shows such as ''Davy Crockett'' and ''Zorro'' to baby-boom viewers who are now parents with children of their own. A new series called ''Mousterpiece Theater'' will offer vintage cartoons introduced by George Plimpton in a droll send-up of the public-television series narrated by Alistair Cooke. New Series Being Offered

While one-third of the channel will have recognizable Disney images, Disney executives are hoping that viewers get hooked on its 12 new series. Among these programs are ''Welcome to Pooh Corner,'' a daily half hour of stories and songs featuring life-size puppets of the A.A. Milne characters; ''Wish Upon a Star,'' in which youngsters live out such fantasies as becoming a magician or a Marine; ''Five Mile Creek,'' an adventure series based on Louis L'Amour tales, and ''You and Me, Kid,'' a daily show of activities for parents and young children.

For adults, the channel will offer two magazine shows from Disney's new Epcot Center in Florida. There will also be G-rated films such as ''Can Can'' and ''Popeye,'' starring Robin Williams and Shelley Duval. However, Disney officials concede that they have fewer of these movies than they originally anticipated.

Some analysts believe Disney will have trouble competing with the three conventional networks as well as Home Box Office, the paytelevision service, which has beefed up its family programming in anticipation of the Disney arrival. ''There is clearly an appetite for family programming, but the question is whether people are willing to pay $10 a month simply to get away from sex and violence,'' said one Wall Street analyst who declined to be named.