Baird Mirror Drum Televisor 'kit', built by Harry Arnfield, 1934.

Arnfield was only about 15 years old at the time. From about 1933, mirror-drums and their associated components became commercially available from two or three manufacturers (Baird, Mervyn, Peto-Scott). Like their earlier disc counterparts, Mirror drum Televisors were mostly built by radio amateurs.

The mirror drum, however, could obtain a much larger picture of the semi-experimental television broadcasts then being made by the BBC. 30 accurately located angled mirrors are affixed to the circumference of a drum, one for each line of scanning. Each mirror is inclined at an ever-increasing angle to the previous, which allowed scanning to be performed. A modulated beam of light shines onto the rotating mirrors as they spin, reflecting onto the back of the ground glass viewing surface. Light is provided by a special spherical crater lamp, and modulated by a special Kerr Cell, known as the Baird Grid Cell.

The shop that Harry Arnfield worked at as a Wireless Engineer was called Roland HIll. New Mills has a local historical society. There is a huge arcive of photographs and images of adverts. See N. 13553 Parish magazine, July 1933 where there is little advert for this shop.