'How to build a two valve set', No 6, Godfrey Philips cigarette card, 1925.
© Science Museum / Science & Society Picture Library
The reverse of the card reads: 'Panel with condenser fixed. This is a view of the baseboard and back of panel with tuning condenser in place. The four terminals also have been fitted. These are standard 4 B A Bras W O pattern terminals, but may be otained nickel plated if desired. The two nearest the condenser are (top) serial and (bottom) earth connections. The remaining two are for headphones or a loud speaker.'