An estimated 40 per cent of US TV stations plan to make the switchover to digital from 17 February.
This is despite the recent approval of a congressional bill supporting a four-month delay of the transition from analog to digital TV signals.
The major networks – ABC, CBS and NBC – have agreed to continue broadcasting in analog and digital.
However, the three networks only control around 100 of the total 1800 TV stations involved in the switchover.
The Federal Communications Commission said some 681 – or 40 per cent – have either already ended analog transmission or plan to do so after 17 February.
By deciding to become all digital, these local stations will free up some of the 700Mhz spectrum in those markets that companies such as Qualcomm have bought the rights to use.
The switch is intended to free up spectrum for public safety and provide better television viewing.
The US House of Representatives last week voted to delay the mandatory change by four months – to 12 June.
President Barack Obama is expected to sign the bill into law shortly.
But the delayed bill gave television stations, which say they’ve spent millions of dollars preparing and educating viewers of the switch-over, the option to transition to all digital on the original date.
Supporters of the delay were concerned that 20 million mostly poor, elderly or rural households were not prepared due to a shortage of government coupons meant to defray the cost of converter boxes.