A new breed of high-tech radio programmers think they've found a better way to give music junkies near-perfect renditions of their favorite hits, from Beethoven to Billy Idol, 24 hours a day.

It's called digital radio, and one day it may be zipping out of Earth orbit directly to your car or portable radio or through your TV set.What digital radio promises is impressive: no more hissing signals fading in and out or booming from the bottom of a barrel. No pops or crackles. Compact disc-quality sound.

Several new satellite companies want to offer it; so do traditional AM and FM radio stations. Some cable companies already are offering digital radio to subscribers, for a price.

Because digital radio can produce such a clear sound, the recording industry is keeping a wary eye on a technology that may spur home taping.

But many observers think there's no stopping it.

Today's radio "no longer is state of the art sound quality," says Robert Mazer, a Washington communications lawyer.

Digital radio transforms sound into the precise binary pulses of computers, whereas traditional analog radio changes sound into electrical signals transmitted as rising and falling waves of energy.

Computer technology can reconstruct digital signals into sound that is a near-perfect copy of the original material, which in the music industry nowadays typically is a digital compact disc.

Testing is under way in Japan, Canada and Europe on satellite-delivered digital radio. In this country, the Federal Communications Commission is considering whether to set aside a portion of the already overcrowded airwaves for digital audio broadcasting.

Whatever happens, the new system may render existing radios obsolete.

Some entrepreneurs are hoping to carve out a market for digital audio carried over the unused portions of a cable TV system's wires. The idea has been spreading across the nation slowly since May when Jerrold Communications rolled out its 17-channel Digital Cable Radio.

Two other cable radio offerings - Digital Planet and Digital Music Express - were demonstrated last month to a cable TV convention in Anaheim, Calif.

Carson, Calif.-based Digital Planet began marketing its 26-channel service to a limited number of Continental Cablevision subscribers in Los Angeles in September. Continental is charging customers $8 for the service, which offers formats including rock, classical and jazz, along with radio and cable simulcasts and several regular radio stations. Some channels have commercials.

Customers get a tuner that is connected between the incoming cable and their stereo receiver, where the digital signal is converted back into analog, with only a slight decrease in sound quality.

Although some might wonder why people would pay for what now is offered basically free on traditional radio, Digital Planet President William DeLany said subscriber response "has been just marvelous."

"There are people out there willing to pay a little extra for high-quality sound," DeLany said in a telephone interview from Anaheim.

DeLany said his company originally had projected 2 million subscribers within two years. But based upon the early results in Los Angeles, the service may attract double that number in two years, he said.

Jerry Rubinstein, chairman of International Cablecasting Technologies Inc. in New York, said his company has commitments for the 30-channel Digital Music Express from cable systems representing 15 million subscribers in Denver, Las Vegas, Nev., Chicago, Seattle, San Francisco and St. Louis, Rubinstein said. It should begin in spring 1991.

The music will be commercial free and uninterrupted, Rubinstein said. A computer even will arrange the order in which songs are played.

Unlike Digital Planet, which will have "moderators" telling listeners what they're hearing, Digital Music Express will offer an optional remote control that displays the name of the artist, the song, album title, record company and catalog number.

"The subscriber will have all the information he wants to buy the CD, be it by phone call or by going into a particular record store to get it," Rubinstein said.

The cable radio executives said they didn't want to alienate the record companies. For that reason, they won't publish advance play lists or play albums end to end.

The recording industry still fears the introduction of digital audiotape recorders, particularly when digital radios begin picking up digital audio broadcasts. To offset the potential loss of revenues, record manufacturers want a performance royalty or a tax on tapes or recorders.

The U.S. Copyright Office is looking into the issue. It also is considering a proposal that digital radio broadcasts be scrambled, thereby turning them into subscription-only services.

Radio stations are urging the FCC to let them provide digital audio, arguing that satellite delivery would weaken the tenets of the 1934 Communications Act that enshrines the concept of "localism."

Radio stations also say satellites would siphon away crucial revenue.

Satellite broadcasters want to use portions of the radio spectrum now occupied by UHF-TV channels 57-66. Broadcasters say that spectrum should be reserved for emerging high-definition TV service.