Loewe multiple valve radio receiver, late 1920s.

'How to build a two valve set', No 22, Godfrey Philips cigarette card, 1925.

Burndept Ultra IV radio receiver, 1923.

Frenophone loudspeaker amplifier, 1922.

Frenophone loudspeaker amplifier, 1922.

5-valve R1 Radio receiver, 1922.

Tuning device for Mullard Raleigh PM broadcast receiver, 1927.

Cosor 'Melody Maker', all electric radio receiver, 1931.

Cosor 'Melody Maker', all electric radio receiver, 1931.

'How to build a two valve set', No 13, Godfrey Philips cigarette card, 1925.

Marconi's first tuned transmitter, 1897.

Marconi's first tuned transmitter, 1897.