Starting this morning, Channel 50 will no longer be WFTY but will have the call letters WBDC -- reflecting what vice president and GM Michael Nurse calls "WB50's commitment to the WB Network and our commitment to offering the best in entertainment in the Washington market" . . .

As WFTY, the UHF station began operations in Washington as an independent in March 1986 and earlier this year became the Washington affiliate of the new WB Television Network . . .

Aside from the Warner Bros. prime-time and Kids WB programming that affiliation attracted, WBDC carries Baltimore Orioles games, Atlantic Coast Conference basketball and football and, starting this fall, Washington Bullets NBA and Washington Capitals NHL games . . .

The 47th annual Primetime Emmy Awards won a rare Sunday night for Fox Broadcasting, according to preliminary figures . . .

The Emmys averaged a 15.6 rating and a 24 percent audience share in Nielsen's 33 big city overnight markets. In Washington the ceremonies, which ended right on time, just moments before 11 p.m., averaged 16.2/25 on Channel 5 . . .

Among the big markets, the show did a 20.1/30 in L.A. and a 16.9/25 in New York . . .

A year ago, when the Emmys aired on ABC, overnights in 32 big cities produced a 17.1/26, which turned into a 14.6/23 national count eventually. That included a 15.0/22 on Channel 7 . . .

In midsummer, The Discovery Channel, responding to a request from the producers of the NBC hit show "Mad About You," gave the series permission to use the TDC name in what was to be a continuing story line in the new season -- in which Paul Buchman (Paul Reiser) gets a job turning out documentaries for TDC, and his long hours put a strain on his mar riage . . .

Last week, the Bethesda-based cable channel got a call from the NBC legal department in Burbank, Calif.,informing TDC they'd decided not to use the Discovery name "for legal reasons." So now when the season-opener of "Mad About You" shows up on Sunday, Sept. 24, Paul will take a job with the fictitious Explorer Channel instead . . . Now This

The Oakland Raiders/Washington Redskins game on NBC averaged a 29.0/61 from 1 to 4 p.m. on Channel 4 . . .

Two years ago, then-congressional correspondent Henry Champ left NBC after 12 years with the network to join Canadian Broadcasting Corp. as host of its morning show . . .

After two years of weekly commutes to Halifax, Nova Scotia, Champ has returned to a permanent post at the CBC bureau, where, effective yesterday, he is in charge of the American input for CBC's 24-hour news service. That includes daily air time, starting with an insert of U.S. news into the morning broadcast . . .

When the House telecommunications subcommittee holds a hearing today on the future of public broadcasting, including further authorizations for the Corporation for Public Broadcasting, it will hear from the senior managers of 82 major public TV stations around the country who have sent chairman Jack Fields (R-Tex.) a letter opposing any proposal permitting advertising on public TV . . .

"While appearing to offer an easy solution to public television's funding dilemma, advertising is antithetical to our guiding principles, and is economically unsound," the executives charge. "We believe it would unfortunately lead to the eventual demise of America's most respected and valued television service" . . .

They warn that for "more than 40 years . . . public television has abided by a covenant with its viewers to bring them noncommercial television -- television that answers their needs as citizens in a democracy and not merely as consumers in a marketplace. Advertising would break that covenant, turning America's only public service television system into just one more ratings-driven network" . . .

The managers also mentioned the frequently cited studies that "have concluded that advertising would yield a net loss for the public television system because new advertising related expenses and lost revenue from existing sources would outweigh new advertising revenue" . . .

The letter is to be read at today's hearing, which begins at 1 in Room 2123 of the Rayburn House Office Building . . . Moving Right Along

No sooner had "NYPD Blue" won the Emmy for best drama Sunday than ABC Entertainment lashed out with the announcement that the third-season premiere of the series would be Tuesday, Oct. 24, in its usual 10 p.m. time slot . . .

In the return episode, tactfully called "E.R.," Det. James Martinez (Nicholas Turturro) faces paralysis after being wounded in the line of duty, while the squad snarls over the news that his assailant is a government informant -- and may be allowed to walk (frankly, I wouldn't want to be that guy on Oct. 24) . . .

Meanwhile, "Murder One," the new Steve Bochco courtroom drama, will warm up the audiences for "NYPD" (and hopefully gain its own appreciative fandom in the process) by taking up the "NYPD" Tuesday slot for three weeks in a row, starting Sept. 19, before moving to its regular timeslot in Death Valley, i.e., the 10 o'clock Thursday hour opposite NBC's "ER" . . .

(Wide-awake TV Column fans will have already realized that Tuesdays, Oct. 10 and Oct. 17, at 10 are unaccounted for. ABC assures us that Game 1 of a major league baseball league's championship will be seen on the 10th, while no decision has been reached about the 17th) . . .

ABC also announced that Robert Mitchum will guest star as Marshal MacBride's pa on the Monday, Sept. 25, episode of "The Marshal," which will air on Channel 7 at 2:30 a.m. that Friday night (or Saturday morning) . . .

A spokeswoman for CBS Entertainment yesterday confirmed that the network "is in the process of negotiating a development deal" for the rights to Truman Capote's "In Cold Blood." Brooks Barton added that "it's too early in the process to comment further" . . .

Variety reported yesterday that the rights to the fact-based book, which Columbia turned into a chilling movie in 1967, recently reverted back to the Truman Capote Literary Trust and that "after somewhat feverish bidding," producer Robert Halmi, Hallmark Entertainment and CBS paid more than $550,000 for the book, which CBS aims to turn into a miniseries . . .

Elyse Weiner has been named producer of fX cable network's "Under Scrutiny With Jane Wallace" . . .

Weiner is a former producer for "ABC World News Tonight" and "World News Now" and has been with the Wallace program for a year. She replaces Richard Cohen, who reportedly will remain with fX to develop new political programming for the network . . .

NBC News anchor Tom Brokaw will chat with the much-interviewed Gen. Colin Powell on next Monday night's "NBC Nightly News" in a special edition of the show's American Close-Up segment, usually seen on Fridays . . .

The interview was conducted at City College of New York about 10 days ago. CCNY, says Brokaw, "is where it all began," when the former chairman of the Joint Chiefs of Staff and possible 1996 presidential candidate joined the ROTC . . .

Last Thursday's MTV Video Music Awards telecast -- which took a bite out of the big network audiences -- averaged a 6.4 rating and a 10 share, attracting some 6.3 million viewers, according to MTV . . .

The cable network noted that viewership was up 5 percent from last year's awards cablecast, at a time when audiences for awards shows on the telly generally have been dropping. The ratings are based on an MTV universe of some 61 million cable homes . . .

United Paramount Network (UPN), which is seen on Channel 20 here, will expand its prime-time entertainment schedule to a third night early next spring -- during the week of March 6 . . .

UPN already airs programming from 8 to 10 p.m. on Mondays and Tuesdays, as well as a two-hour movie at noon Saturdays and an hour of children's programming at 10 a.m. on Sun days . . .

No details yet on the additional programming but Paramount reportedly has quite a few projects in the pipeline. UPN currently is affiliated with some 150 stations around the country . . .

More Ratingzzz Newzzz: Sen. Packwood's appearance on ABC's "20/20" averaged an 11.7/22 in the Friday night national count. He drew a 13.3/24 on WJLA here . . .

Saturday night, Fox introduced its revised lineup, which produced a 6.6/12 for the night. The new "Prestone Episodes" debuted with a 6.0/11 in the 33-city overnights, which included a 10.0/19 on WTTG here . . .

On Sunday, the WB network introduced four new series and averaged a 2.2/4 in the 33 overnight markets. Each national ratingzzz point represents 955,000 TV homes; a local point, 18,835 TV homes . . .