WASHINGTON - ALL US television stations have switched from analog to digital broadcasts and the number of households without a signal has been dramatically reduced, the Federal Communications Commission (FCC) said on Saturday.

'All full-power television stations in the United States have ceased analog transmission and are now broadcasting only in digital,' an FCC statement said.

Neilsen Co said on Wednesday that 2.8 million US households - 2.5 per cent of the television market - were 'completely unready' for the switch.

'Younger, African-American and Hispanic homes are disproportionately unready, while the elderly are the most ready,' according to Nielsen.

'Up to three million household were unprepared at the beginning of the week,' acting FCC chairman Michael Copps said in a conference call with reporters on Saturday. 'Over the course of the weekend we'll get much closer to zero,' he said.

Mr Copps said 'only a handful of stations' of the nearly 1,000 making the switch on Friday reported any problems including one in Memphis, Tennessee, which had to deal with a tornado.

He said the FCC help line had received some 317,000 calls from people who were having difficulty making their television work but only 'three per cent of the calls were from people who were unaware of the transition.' Ten per cent were from people who were aware but unprepared.

Major TV networks such as ABC, CBS, Fox and NBC were among those making the switch on Friday.

In a statement, Mr Copps said the 'historic transition to digital TV is an important step forward in US broadcasting, offering consumers access to more free over-the-air programming as well as higher quality pictures and sound.

'The transition also frees up valuable airwaves for emergency communications and advanced wireless services,' he said. -- AFP