Viewers who weren't ready for the digital television switch Friday were probably wondering why Adam-12 appeared on screen at noon instead of the Channel 8 news. Or, at 12:30 p.m., Dragnet.

But most viewers seemed aware that Friday marked the end of the analog TV era, as all over-the-air broadcasts across the U.S. are now in digital format only. Those who weren't probably saw static, or, if the signal swapped with another channel in the change, the wrong program.

ABC affiliate WFAA-TV (Channel 8) flipped the switch at noon Friday to turn off its analog signal and go digital.

By 4:30 p.m., the station had received about 600 phone calls from viewers.

"Most calls were from people who know what's going on and have specific questions," said Dave Muscari, vice president for product development at Channel 8.

It appeared to be a relatively smooth landing after what Muscari called "the largest single public awareness effort in the history of the United States."

Muscari estimated that broadcasters, the federal government and others ultimately spent more than $1 billion and more than a year on the education program.

Even so, the Federal Communications Commission estimated in late May that 6.67 percent of Dallas-Fort Worth households with TVs – more than twice the national average of 2.9 percent – weren't ready for the switch, which had been postponed from its original date of Feb. 17.

But Brian Hocker, vice president for programming at local NBC affiliate KXAS-TV (Channel 5), said Friday afternoon that the number of viewer calls was lower than expected after the station turned off its analog broadcast at noon.

"Fortunately, we were prepared for the worst and didn't experience that," he said.

The larger prime-time audience had not tuned in, though, and he anticipated that calls may increase later in the day.

KXAS-TV and other stations said they have special phone banks open all weekend to walk viewers through the process of buying converter boxes, connecting the hardware and scanning in their new digital channels.

Fox affiliate KDFW-TV (Channel 4) is manning a 24-hour phone bank through Monday to field viewers' questions. Kathy Saunders, vice president and general manager of KDFW and sister station KDFI-TV (Channel 27), said most callers right before the switch were asking how to set up converter boxes rather than how to acquire them.

"This week definitely took a turn," she said of the shift. "The positive news is they have their converter box."

Craig Birch, district sales manager for Fort Worth-based RadioShack, hit the streets Thursday to make sure employees at Dallas-area stores could answer customers' questions.

Birch said customers' queries changed in recent weeks from seeking clarity on what's happening to finding out how to be ready.

RadioShack spokeswoman Wendy Dominguez said the company also has hosted community forums in English and Spanish, offering hands-on instructions on getting ready for the switch.

KDFW has been broadcasting stories about companies that can help set up new equipment and about walk-in education centers people can visit. The station also posted instructions on its Web site and has hosted live Web chats with viewers.

Other local stations have also been working for months to educate their viewers.

For viewers who have not obtained a digital-ready TV or converter box, KDFW and KXAS will act as two of the roughly 100 "analog nightlight" stations nationwide that will maintain an analog signal after the change.

Both stations are broadcasting nine-minute videos explaining what to do to restore service.

"I feel that we're doing everything in our power to help our viewers make sure they are as informed as possible," Saunders said.

Local and national efforts appear to have mostly worked, based on information from local stations and the FCC.

A few hours after the switch, the FCC reported that it received more than three times as many calls on Friday as it did on Thursday.

"The FCC and stations have dealt with a number of smaller issues in the field, but most of the things have been resolved fairly quickly," the agency said in a written statement.

"No major issues across the board to report beyond general reception issues, which the FCC will be dealing with on a case-by-case basis and may take some time."

At a Best Buy store in Oak Cliff, customer traffic was light a couple of hours after the switch.

Jonathan Vasquez bought his converter box in October and was prepared for the transition.

"I think it's pretty cool," he said. "Not having to adjust the antenna is nice."

Sherron Greeson bought her converter boxes earlier this year, but she and her husband had not set them up because of a recent move.

"I don't think much of it," she said of the required change. She was out while her husband was at his mother's house, where after at least an hour he had not been able to install the converter using the on-air instructions.

"As far as the actual change-over, I think it's difficult."

glinch@dallasnews.com; vgodinez@dallasnews.com