1923 · Galena Crystal Receiver · Work 805 of 1,871
A crystal wireless receiver of 1923 on a table in the front room of a terraced house in London on a winter evening, a box of polished red-brown mahogany twenty centimetres across, its lid closed, its sloping top a plate of dark brown ebonite with a large black knob on a round brass plate, at its right a small horizontal glass cylinder with brass end caps holding a silver-grey crystal and a fine bent wire, headphones on a green cloth cord worn by a woman in a knitted cardigan seen from behind, a man bending over the glass cylinder, firelight from the right.
What it was used for
The Gecophone Crystal Detector Set No. 1 of the General Electric Company Ltd. was a 1923 broadcast receiver with terminals for aerial, earth and headphones. A cat's whisker on a piece of crystalline galena rectified the signal; per the Science Museum the set needed no batteries but used the power in the radio waves themselves to drive the headphones. In 1923 it cost 5 pounds 10 shillings. With the recommended aerial of about 100 ft and a 20 ft earth wire it could receive signals up to 30 miles from a BBC transmitter; 2 pairs of headphones could be connected at once.
What was new
Like all commercially made British broadcast sets of the time, the set carries the stamp "Type Approved by Postmaster General", which the Science Museum dates to between November 1922 and September 1924; per Electronics Notes only a British-built set from a member company of the British Broadcasting Company could carry it, the Gecophone No. 1 under approval number 102. The barb is in the price: of 5 pounds 10 shillings, 7 shillings 6 pence, that is 6.8 per cent, went to the BBC as a royalty. The listener paid the broadcaster by buying the receiver - and listened through headphones, not a loudspeaker.
What the sources leave open: Science Museum and Electronics Notes give different ranges (30 miles with a 100 ft aerial at the museum, about 25 miles per the sales literature at Electronics Notes). This is not a contradiction: one states an aerial, the other reports the brochure. Sales figures are unverified; Electronics Notes only infers a large quantity from serial numbers.