NEW YORK: The warning message that many US television sets could blackout next February - when the nation's analog signal is switched off - still has some way to travel, according to Nielsen Media Research.

Around 25 million homes coast-to-coast have at least one analog-only TV set and that ten million of those households are  "completely unready" for the digital transition. Meaning all those sets would go dark .

The Nielsen report concludes that Hispanic and African-American homes are disproportionately ill-prepared, despite a $1 billion (€635m; £506m) government advertising campaign and the provision of $40 vouchers to subsidise the cost of set-top converter boxes.

Younger households are also less ready than others.

Says Nielsen svp Patricia McDonough: "Some people expected that senior citizens would be among the most affected. But looking at 65-years-plus households, they are among the most prepared."

The latest data is intended to help local broadcasters assess how much more education is needed - for  example in respect of Spanish-language viewers.

Households that speak only Spanish make up two percent of the US population, but account for 10% of the unready households.

Nielsen evp Sara Erichson expects most viewers to buy new equipment or converters boxes as the 17 February deadline nears but warns: "We believe some households won't take action until they turn on a TV on February 18 and realize they can't watch their favorite broadcast shows."

The DTV transition could have a marked impact on ratings. If older TV sets drop off the radar next February, viewer numbers and ratings will also slide, affecting the local stations and TV networks that sell airtime tied to them.

Data sourced from New York Times; additional content by WARC staff