ON AND OFF THE AIR:
* What makes a television series click with viewers? The question arises again with some good, good news for many viewers: CBS' quirky "Northern Exposure" (Mondays at 10 p.m., Channel 11) has not only been renewed by the network, but given a two-season commitment.
One consistent feature of every good show applies particularly in this case: It does not rely solely on one or two star characters. For "Northern Exposure's" fictional town of Cicely, Alaska, (actually Bellevue, Wash., where the show is taped) just teems with engaging characters.
Yes, the slowly growing attraction between Fleischman (Rob Morrow) and Maggie (Janine Turner) provides a key part of the mix.
But producers John Falsey and Joshua Brand have allowed a number of other regulars to project an uncommon depth and believability.
Media Monitor is particularly fond, for example, of the taciturn native receptionist Marilyn Whirlwind (Elaine Miles) and philosopher/disc jockey Chris (John Corbett).
Others may favor the May/December romance between Shelly and Holling (Cynthia Geary and John Cullum), the innocent wisdom of tribally adopted Ed Chigliak (Darren E. Burrows) or the domineering bombast of Maurice (Barry Corbin).
* On the other side of the series survival ledger, ABC's Saturday series "Capitol Critters," which premiered in late January, is entering into the uncertain future of "hiatus."
Seven episodes of the show from Steven Bochco about the animal residents of the White House made it on the air, and six are in the can. No word on when they might be seen.
* Those nice nightly reruns of "Late Night With David Letterman" on cable's Arts & Entertainment network (7 p.m. Monday through Friday) apparently will also disappear as of September.
NBC said last week that it had a three-year contract with A&E for the shows, but that an annual review was built into the deal. And Mr. Letterman reportedly objected to continuing the reruns past the first year.
* Remember "Muskrat Love," the simpering, big hit record from The Captain and Tenille? Forget it. Singer Toni Tenille is much better with the pop standards of "Those Fabulous Forties," one of tonight's specials in Maryland Public Television's ongoing pledge drive (at 11 p.m.).
Hal Linden ("Barney Miller") is Ms. Tenille's co-host, and the show follows another airing (at 9 p.m.) of "Big Ballroom Bash," seen in the first weekend of the membership drive.
* WNUV's (Channel 54) 8 o'clock movie tonight is a good one. In "Max and Helen," a gripping, made-for-cable drama/love story, Martin Landau plays Nazi-stalker Simon Wiesenthal, and Treat Williams and Alice Krige persuasively portray a couple sundered by the Holocaust.