Irwin Darack and his wife, Sue Anne, were tucking two bouncy grandchildren, ages 5 and 7, to bed when they got a big surprise on the television.

The Cartoon Network, the Daracks' tried-and-true sleepy-time channel, was a static gray with no sound - "like in the old days when a TV station went off the air," said Irwin Darack. Fiddling with channel 56 couldn't get

Goosebumps

to life on the TV.

The loss of Cartoon Network in the Daracks' spare bedroom in Bucks County is part of a sweeping change taking place at Comcast Corp., the nation's largest pay-TV system, as it converts to a mostly digital network.

So far, about 70 percent of Comcast's 24.4 million customers have upgraded to digital, leaving about 7.3 million nondigital holdouts who face a mandatory digital upgrade. Comcast customers also have the option of remaining with a bare-bones legacy analog service. There are about 360,000 nondigital holdouts in the Philadelphia region.

The most apparent changes for customers is the cancellation of analog channels that, in some cases, have been replaced with high-definition channels.

In recent weeks, besides the Cartoon Network, Comcast has eliminated analog channels for Style, G4, Leased Access, AMC and C-Span 2 in parts of the Philadelphia area.

Comcast's so-called digital migration holds great promise for the Philadelphia company because it will boost the data-carrying capacity of its network. An analog-only cable network fits 116 channels of programming. A digital-only network fits 1,116 standard-definition channels.

But Comcast could lose customers upset with a final change to digital, which makes many televisions obsolete without a converter box.

And critics say the cable giant's actions are badly timed and adding confusion to a separate, government-mandated program to switch over-the-air broadcasters to digital transmissions Feb. 17.

Consumers Union, the nonprofit publisher of Consumer Reports, said in an Oct. 29 letter to the Senate Commerce Committee that Comcast appeared to be using the over-the-air digital switch to "strong-arm confused consumers into paying much more every month for cable programming they have previously received at no extra fee. We believe the timing of this rate hike is deceptive."

Comcast should adjust cable bills to account for dropped analog TV channels, or distribute free digital-to-analog converter boxes, Consumers Union says.

Joel Kelsey, Consumers Union policy analyst, said in an interview that cable companies should "be rewarding their customers with free boxes or adjusting their rates for the lost channels."

He said the group also got complaints about Time Warner Cable Inc. and Cablevision Systems Corp.

"In some markets, cable companies have removed the TV Guide channel," Kelsey said, leading analog customers to lease a special converter to get the guide. "That is like going to a restaurant and having to pay for a menu," he said.

FCC Chairman Kevin Martin is investigating Comcast and a dozen other cable companies for the analog-channel changes and converter boxes. The FCC sent a letter to Comcast on Oct. 30 requesting information back to November 2006. Answers were due Thursday, but have not been made public.

"The analog customer may be paying the same price even though they have less channels," FCC spokeswoman Edie Herman said.

The National Cable & Telecommunications Association said the FCC's investigation into the cable industry was "a broad fishing expedition." The industry group said in a response Wednesday to the FCC that the investigation was part of Martin's pattern of unreasonable actions toward the cable business.

Comcast's timing of its digital migration is independent of the government program for over-the-air broadcasters, senior vice president Derek Harrar said.

"We are trying to figure out the best way to make this a good solution for our customers," Harrar said. "We are going to do everything we can to bring them into the digital age."

Comcast has developed special offers, code-named Project Cavalry, to keep nondigital customers from bolting to competitors as it goes almost all digital. Customers who face a mandatory digital upgrade will be eligible for a free cable box and two free digital-to-analog converter boxes, or DTAs, Harrar said.

Comcast says it could distribute 25 million DTAs, which are about the size of two decks of cards, to customers in the next year or two.

The company also will maintain a customer's existing cable rate when they are switched to digital, Harrar said. The offer is "not a promotion. It's your package," he said. For those opposed to digital, Comcast will keep a basic analog tier of 20 to 30 local broadcast channels.

Comcast's first full-digital conversion will take place in Salem, Ore., where it has been announced. At this final stage, Comcast will cancel the analog versions of major cable channels, such as CNN, ESPN and Lifetime, a company official said. The company did not say when the final migration would happen in Philadelphia. Most of the markets will be converted by 2010. Some could spill into 2011.

For now, however, the Daracks of Doylestown Township, who have digital service, cannot get the free DTAs from Comcast, and Irwin Darack has been scrambling to find a solution for two TVs without cable boxes.

Irwin Darack lost the Cartoon Network in the spare bedroom and in the kitchen. A Comcast customer service employee told him in an online chat that he could buy a converter box, or lease one from Comcast for $8.90 a month.

The converters Darack found for sale online were for satellite. A Circuit City Stores Inc. salesman told him he could buy a digital-to-analog converter that the government is subsidizing for TVs with rabbit ears, Darack said. But those converters do not work with cable service.

Comcast spokeswoman Jennifer Khoury said Friday that the converters were not being sold in stores.

"It's extremely confusing; nobody knows what's going on," Darack said.

Contact staff writer Bob Fernandez at 215-854-5897 or bob.fernandez@phillynews.com.