Periodically, Americans nurtured on television rediscover radio. They find that radio is, basically, TV without the picture tube. It can be very useful.

When TV was zooming to popularity, doleful predictions were heard that radio was on its deathbed.

But if radio is dying there is little visible evidence of it. Anybody who has attempted to buy a radio station recently has discovered that even those with poor signals, even the FM stations with the fewest listeners, feteh sky-high prices.

I was pleased to note that Friday's editions of The Washington Post contained an appropriate reflection of radio's latest rebirth. Friday's Post included a radio column.

There is much to be said about radio, and I hope that in the weeks ahead our radio column will help encourage interest in the medium.

Friday's mention of the all-news format touched on a subject that is of great interest to me. Not too long ago, Washington had three all-news stations: WTOP, WRC and WAVA. They carried not only news but feature material -- specialized coverage of such fields as sports, weather, pets, horticulture, religion, medicine, business, book reviews, reviews of the lively arts and other cultural topics.

Listeners learned when to tune in to hear things of special interest to them, just as they learn to find the comic pages in a newspaper. A friend who is active in the stock market used to tune to WTOP at 21 minutes past the hour for the Associated Press market report and then switch to WRC at 26 minutes after the hour for that station's report from a local brokerage firm. "Each station covered different points," he explained, "and together they gave me what I needed to know."

WAVA and WRC now have abandoned the all-news format, and WTOP's service has deteriorated. I am resigned to its engineering deficiencies, which cause wrong recordings to be played, or to be cued in at the wrong times, or two recordings to be played simultaneously, or to be played in garbled fashion -- things that happen frequently of late. I accept such lapses as I would typographical errors. I assume somebody at the station cries out in pain when they occur and is trying hard to minimize them.

What does concern me is that our only remaining all-news station contains so little news these days.

If the teachers' union or the transit workers' union takes a strike vote at 8 p.m., we may wait for hours to find out whether the schools or the transit system will be in operation the next morning. WTOP has a game in progress, and that takes precedence.

After midnight, WTOP joins the Mutual Network for a talk show. I do not care for talk shows because most of the people who call in are inarticulate and take forever to say something; and after they get it said, it usually turns out to have been not very bright. I especially dislike Mutual's talk show because its host projects an image of rudeness and arrogance.

During the day, when the all-news format is supposedly in effect, WTOP is very busy with commercials and public service announcements (some of which I have memorized) and teasers about upcoming news. Worst of all are the nine zillion commercials that WTOP broadcasts on its own behalf each day to tell us how wonderful the station is. WTOP separates these innumerable recorded announcements with snippets of news.

Features are broadcast in a general time frame rather than at precise times. Among these, the stock market reports must be mentioned as special offenders.

Examplo: CBS News gives the Dow Jones industrial average at about five minutes after the hour, say 11:05 a.m. The Associated Press supplies an update apparently based on 11:15 figures, and the station airs this when it gets around to it, usually between 11:20 and 11:27. Then at 11:55 the station gives its own "update" by repeating the 11 a.m. averages . WTOP's news room apparently is not aware of the AP update it aired a half-hour earlier.

I think there is tremendous need for a good all-news station in every large urban center. Despite the large operating costs associated with an all-news format, such stations can be operated at a profit. WTOP ought to be encouraged to reexamine its practices and policies and chart a new course toward financial and artistic success.

Radio's obituaries were written prematurely by TV enthusiasts, but a clear and present danger does exist. TV can't kill radio, but radio's owners and operators can.