"Well we've had our fun," Rich Little says early in his ABC special tonight. He can only be speaking for himself. "Rich Little's Washington Follies," at 8 o'clock on Channel 7, is to fun what chocolate egg creams are to diet - anathema.

As rigorously unamusing as the Little show is, "Alan King's Second Final Warning," another ABC comedy special, at 10 p.m. on channel 7, seems even more disagreeable, partly because it is staged as King's personal tantrum on behalf of the middle-class homeowners of America. The portly pied piper of polyester protest grows more grating and less hilarious each year.

King's hour at least has a handsome surface. He operates out of a futuristic set suggesting NewsCenter 4 crossed with Dr. Frankstein's lab. But the material, by eight laggardly writers, is barren. King seems more and more the clone of Howard Beale, mad prophet of the airwaves in Paddy Chayefsky's "Network," except that Beale made more sense and had the decency to pass out now and then.

The Rich Little show takes one hour to spoof and lampoon Washington and politics with far less effect than Johnny Carson achieves on even the worst nights of his monologue. In addition, the special epitomizes ABC's cynical cross-plug philosophy of untertainment; the "guest stars" are Dick Van Patten of ABC's "Eight Is Enough" (Van Patten also guest stars on the King special), Robert Guillaume of ABC's "Soap," Tom Bosley of ABC's "Happy Days," and Suzanne Somers of ABC's "Three's Company."

All of them are ABC's miserable - with the possible exception of Somers - and tend only to get in the way of Little's adroit impersonations, which are losing whatever conceptual integrity they once had because the writers force them into ill-fitting formats and formulas. Little might as well hang it up if he's going to put his talent to such abysmal endeavors.

On both shows, the writers have tried to pass off ugly tastelessness for irreverence and so we have Little as Truman Capote complaining about a "fever blister" on Jacqueline Kennedy's lip and Little as Carol Channing observing that the late Lyndon B. Johnson is picking up his wife Lady Bird by the ears. King's show features a sketch about a married couple's lovemaking being interrupted by their little boy - a real shriek if one is into smut.

Because the subject matter is rare for local television, a two-part special on "The Dynamics of Black Radio," starting tonight on "Harambee" at 7:30 on Channel 9 and concluding next week has to be welcome, but it tries to cover far too much at once.

Producers Les Edwards and R. Dwight Bachman suffer from muddled priorities and quirky editorial judgment. An opening history of blacks in radio is enlivened by an interview with ex-Washingtonian Harold Jackson, "the first full-time black announcer" in radio and now a New York station executive. Unfortunately, the interview is over before it's begun, and the program goes on to daily with such uninteresting topics as disco music.

It's clear that a Washington broadcaster who huffs and puffs that "communications must meet the needs of the community" should have gone straight to the cutting room floor, and that if the subject of radio ratings is going to be brought up, there should be some discussion about why listening patterns change so swiftly though TV viewing patterns do not.

Still, the half hour is put together in a basically fluid, straightforward way, and if the script is pocked with such slim insights as, "These people are obviously having fun" over disco footage, a good number of provocative questions are raised.

"Black Radio" marks a frustrating first plunge; what the producers ought to do is get back to Jackson and devote an entire show to him. He could probably tell more about the development of black radio through his own experiences than can be gleaned from a cursory overview like this one.