TODAY’S delve into the Lancashire Telegraph archives has unearthed this fascinating glimpse inside one of East Lancashire’s biggest employers.

Taken in 1973, the photograph shows workers at Mullard’s in Blackburn soldering leads on to flat foil capacitors in the as part of the production of circuit boards.

Mullard’s was one of the first companies to move on to the Whitebirk Industrial estate in the 1930s and before the outbreak of the Second World War it was producing 6.5million valves a year for radio sets.

The advent of the TV age saw production demands shift and the Blackburn factory was at the forefront and by the the time this picture was taken the factory occupied a site measuring 46 acres of land and employed over 5,000 people, primarily producing components for televisions.

By the 1980s the factory was one of the world leaders in CD technology.