Television without stereo is like driving a sports car with an automatic transmission: It gets the job done, but it's not as much fun.

High-definition TV broadcasting still is years away, but the advanced technology of TV sound is readily available in the marketplace.Nowadays, it's possible to hear brilliant, high-fidelity sound on television, as well to see bright, natural colors. In other words, today's TV soundtrack is nothing less than a high-fidelity, FM stereo broadcast with moving pictures.

People with monaural television are missing an entire dimension of the television experience. Stereo TV creates the illusion of space by "imaging" sounds over two channels, mimicking the way humans hear.

When two-channel TV sound is pushed through larger twin, better-quality loudspeakers, the illusion of space, the depth and source of sound effects and the richness of a musical score are immeasurably enhanced.

And in a nation where the typical American household keeps the tube on for as much as seven hours a day, why not have the best?

It's not that there aren't any programs to watch. ABC, CBS, NBC and the Fox Broadcasting Co. originate all their programs in stereo. NBC has 147 of its 208 affiliates with full stereo capability. That covers about 90 percent of the country. ABC has 87 stereo affiliates of its 225, and CBS about 90. About 40 PBS stations have stereo capability. And even the 133-affiliate Fox has stereo affiliates.

And it's not that there isn't any hardware.

According to electronics industry estimates, stereo color TVs will account for more than 30 percent of the TVs sold this year; in June, stereo color TVs were in 21 percent of U.S. households.

Stereo videocassette recorders - which plug into your home hi-fi system - accounted for about 15 percent of the nearly 10 million VCRs sold this year. By 1991, the industry expects to sell 2 million stereo VCRs.

Don't forget that virtually all movies on prerecorded videocassettes these days have stereo soundtracks, usually with Dolby noise reduction.

Speaking very generally, a stereo VCR or TV will cost $100 to $300 more than its monaural counterpart, but bargains always can be found. And remember, any stereo VCR makes any TV a stereo TV.

There's one other little benefit to a stereo TV or VCR: A setting marked SAP or MTS, which stands for Secondary Audio Program or Multi-Channel Television Sound. The setting puts an extra audio track at your disposal, and PBS has been making good use of it for years.

In New York City, public TV's WNET airs the National Weather Service forecast 24 hours a day - when it's not using the channel for simultaneous language translation or a commentary track for the visually impaired.

PBS series with descriptive narration tracks available this year include "Great Performances," "Mystery!" "DeGrassi High" and "Wonderworks."

PBS' "MacNeil-Lehrer Newshour" is broadcast with a simultaneous Spanish translation.

Denver's KRMA uses the SAP channel for weather reports, and Los Angeles' KTLA has done its local evening news in simultaneous Spanish language translation since 1984.

If you have a stereo VCR, DARE TO EXPERIMENT!

Plug your your stereo VCR's "audio out" lines into your home stero system. Put the speakers on either side of the screen. Voila! You now have a stereo television.

Want to hear the Secondary Audio Program? Push that little SAP button on your VCR and you'll be able to receive the SAP channel.

"You will also be able to record the secondary channel and preserve it for later use," said Nancy Tanny, head of WNET's SAP services. "That's something I know our blind and visually impaired viewers are doing."

Tanny said WNET's weather reports on the SAP channel also generated a number of interesting calls from people who didn't know anything about SAP.

"They were just puzzled about why they were seeing `Great Performances' and getting the weather report," she said.