Iain Logie Baird, TV curator at the national media museum and grandson of John Logie Baird (inventor of the first television) will be judging entries from across England, Scotland, Northern Ireland and Wales.

Invented in 1936, televisions became a mainstay in UK living rooms in the 1950s with the arrival of public service broadcasting, and the search is on to find any working sets which date from the 60s, 70s or even earlier.

The owner of the most ancient telly will win the chance to have it upgraded to ensure it's ready for the digital switchover. They will also receive a new Panasonic Viera Plasma TV, home cinema system and a Humax digital receiver and recorder, worth a total of £1,600. Five runners up will each receive a state of the art digital recorder from Humax.

"There is a serious message behind this competition," said Jon Steel of Digital UK. "It is a myth that viewers need a brand new television to make the switch to digital. Even televisions which screened the Queen's Coronation or the first moon landing, can be converted. Switching to digital needn't be costly."

The UK's digital switchover is already underway and is gathering pace. Over five million households will switch this year, including three million in the Granada region in November.

If you think you have a working old set which is in with a chance of winning, send us the make, model and age of your TV, plus a photo of it, by clicking here or via post to Oldest TV competition, Digital UK, The Met Building, 22 Percy Street, London, W1T 2BU.