This is an example of home constructed crystal sets. Because of the large cost of factory built sets in the 1920’s many wireless enthusiasts chose to build their own receivers only a few components were needed (coil wound on former, crystal, variable capacitor, knobs, brass terminals, wire and headphones. A good outside Aerial & Earth were essential) and they took great pride in the finished appearance. The receiver on the right is unusual in that it does not have a variable capacitance tuning knob and relies on two semi-circles of brass studs connected internally to series tapped coils for course frequency selection.
The minimum weekly wage in 1925 was£1-11s-8d for a 50hour week.