IF YOU switch on the TV in three weeks' time to find a blank screen in lieu of the final match of the State of Origin series, don't be too alarmed.

On July 9, all free-to-air channels in the Clarence Valley will be moved to a new location on the broadcast spectrum, meaning viewers will have to retune their digital televisions, set-top boxes or digital TV recorders to access their favourite channels.

Temporary interruptions to all services are expected on the day, and the Department of Communications has warned service shortages before and after the retune may occur due to work being carried out on the transmission site.

Grafton's Harvey Norman electrical franchisee John Stewart expects to see an influx of people concerned their television is broken when the switch is made next month.

"About two years ago, one of the stations moved to a different frequency and many thought their TV was faulty," Mr Stewart said.

"It caused problems last time and it's going to cause problems again this time."

To combat this, Mr Stewart said all Harvey Norman staff would be trained on the changeover to help it run as smoothly as possible for Valley residents.

"Because most people are on digital, it's an automatic process but one problem we face is a lot of people lose their TV manuals," he said.

"We'll assist people (with directions) to retune them as we can, just as a service."

Clarence Valley's retune is part of a national program expected to be complete by the end of 2014.

Find out more at www.retune.digitalready.gov.au

How do I retune?

Start by pressing the 'menu' button on your remote then look for 'set-up' options.

Select words like 'channels' or 'auto-tuning' and follow the prompts.

When the scan finishes, you should be able to receive all digital TV channels.