This was a very expensive set when new, costing GBP68-8-0 (about half the price of a very basic motor-car). It is sometimes referred to as the 'Straight Eight', (although the valves are not arranged in a straight line like the cylinders of a straight-eight car engine). The detector, nick-named the 'Kirkifier', was invented by H.L. Kirke, a member of the Marconi 2MT team in 1922 and later head of the BBC Research Department.