A bomb went off at KTVX-Ch. 4 last week, and the staff there is still sort of in shock.

No, it wasn't an incendiary device of any kind. It was a resignation - general manager David Woodcock is leaving the station after more than seven years.He's on his way to Los Angeles to become general manager at Disney-owned KCAL.

Not only did it come as a shock on the personal level - Woodcock has to be one of the more popular bosses in town - but it signals the end of an amazing era at Ch. 4. An era that saw the station climb from the local laughingstock to, by some measurements, the No. 1 station in town.

To put it mildly, KTVX was in disarray when it was purchased by United Television Inc. in 1983. Ch. 4's newscasts barely registered in the ratings, and much of the rest of the station's local schedule was just about as bad off.

"A lot has changed," Woodcock understated. "Back in 1983, we were not competitive with the rest of the marketplace. We had a very poor image, and, frankly, that image was deserved.

"It would have been easier to just sign on with a new channel - Ch. 10 or something - instead of trying to overcome the poor image we had."

He said the greatest challenges the station faced were "turning around the news department" and "trying to genuinely convince the community that we were a different station."

And KTVX genuinely has turned things around. Ch. 4 has achieved virtual parity with Ch. 2 and Ch. 5 in the early evening newscast ratings and is a strong third at 10 p.m.

And in the sign-on to sign-off numbers - an average of the ratings of all programs during the broadcast day - KTVX has been No. 1 for the past couple of years.

"To go from No. 3 to No. 1 is something we're very proud of," Woodcock said. "We kind of did what we said we would do, and it's made the difference."

Woodcock is also quick to spread the credit around.

"We've done all this with the people who were already here when I arrived," he said. "A lot of these people have been here longer than I have, and most of the credit should go to them."

Perhaps the most surprising thing about Woodcock's move is that he's leaving Chris Craft/United Television, a company he's worked for for 141/2 years. From 1976-83, he was local sales manager, general sales manager and finally vice president and station manager for the company's Los Angeles station, KCOP.

In 1983, he was given a choice of taking over United's station in San Francisco or the one in Salt Lake City - and he chose Salt Lake City.

"It's hard to be leaving Ch. 4," he said. "After being here for seven years, we're very, very fond of Utah.

"I'm from L.A. I have family there and a lot of friends there. I've always loved California.

"But I'm going to sort of have my cake and eat it, too. I'm keeping my place in Park City, and we'll spend a lot of time there."

And his next challenge is as great or greater than when he took over at KTVX. KCAL, Ch. 9 in L.A., is the No. 7 station in town and has experienced a lot of growing pains since Disney bought it two years ago.

"It's a challenge, but Disney is a great company, and they've made a strong commitment to the station," Woodcock said. KCAL is currently airing five hours of news a day - three hours in prime time.

"They (Disney) put $35 million into news last year," he said. "They certainly have got the money."

Woodcock expects to be in Utah until about mid-April

"They (United Television) have been tremendous to me. I'll be here as long as they need me," he said.

And when Woodcock does head out for California, he'll be missed, not only by his employees but by Ch. 4 viewers (whether they know it or not) - and by one television editor.