With broadcast TV stations preparing to switch to all-digital signals early next year, about 5.3 million U.S. households have taken the government up on its offer of discount coupons for a gadget to ensure their sets will continue to get the picture.

Each U.S. household is eligible for two $40 coupons toward the purchase of converters that sell for about $60, and most have asked for the maximum. The National Telecommunications and Information Administration said Tuesday that 10 million coupons had been requested since the program began Jan. 1. About 856,000 households in California have submitted applications.

"We're doing a pretty good job so far," Meredith A. Baker, head of the telecommunications agency, said at a Senate hearing. "We have a lot more work to be done."

Redemption is going much more slowly, because consumers need to wait for manufacturers to roll out the boxes and for retailers such as Best Buy Co. and Wal-Mart Stores Inc. to stock them. As of Friday, 280,128 coupons had been redeemed, about 17,400 of those in California. The government started mailing the coupons in February, and Baker said the backlog of requests was being worked through.

Lawmakers continue to worry about awareness among consumers; many still don't know that the transition is coming next year, according to recent polls.

On Feb. 17, all full-power TV stations must turn off their analog signals and broadcast only in digital. Although the new method will deliver better pictures, people who use antennas and don't own newer digital sets will need a converter box or their screens will go blank.

"We all just pray this works," said Sen. Ted Stevens (R-Alaska), who is particularly concerned about rural residents who rely heavily on antennas.

As many as 20 million homes get only over-the-air signals. Cable and satellite TV subscribers will get the new signals through those systems, but millions of those homes have extra sets that use antennas. Broadcasters have estimated that 70 million U.S. televisions could need converter boxes.

The Senate Commerce Committee summoned Baker and Kevin J. Martin, chairman of the Federal Communications Commission, on Tuesday to update them on the transition. Sen. Daniel K. Inouye (D-Hawaii), the committee's chairman, told Martin that raising consumer awareness and ensuring a smooth transition should be the top priority of the FCC and the telecommunications agency this year. He requested monthly updates.

Martin said that although awareness was rising, federal officials and a private coalition led by broadcasters still had work to do.

"Too many Americans remain confused about what they need to do about the digital transition," Martin said.

The coupons are a key to the transition, the federal government's way of helping ease the pain of the change, which is designed to free up TV airwaves for public safety use and wireless services such as high-speed Internet access.

Congress allocated $1.5 billion to a program to deliver as many as 33.5 million converter box coupons. Resembling plastic gift cards, they are encoded and must be used within 90 days. That deadline worries Consumers Union because the boxes have been slow to hit stores. On Tuesday, the group urged federal officials to extend the deadline or allow people to reapply if their coupons expire.

People can apply at www.dtv2009.gov or by calling (888) DTV-2009.

jim.puzzanghera@latimes.com