Wireless Set Number 18

Wireless Set No. 18 was the first mass-production man-pack radio station for the British soldier. Made by Pye, the set consists of separate tuneable transmitter (TX) and receiver (RX) units mounted in a back-pack.

If you are on CCF Ops, the trick was show the poor sap about to pick the 18 Set up just how light it is, then fit the integral battery in in the base of the case. Collapse of stout party.

If got your set at a rally, you had to make your own power supply. You either got the filament or HT voltages wrong but in any event you killed a good few valves.

The valves used were fragile 2 Volt filament types. The internal valve filament support springs fractured during rough handling of the set, a way of getting out of Wireless RT Training. Another way was to remove the valves and throw them against a wall at dusk. In the failing light, the satisfying pop was met with a blue flash.

The set used a sectional vertical rod aerial to inflict minor RF shocks to junior ranks. Alternatively a long wire ground aerial could be used to make the set heard over greater distances. In CCF Service, that was the last thing you wanted.

Production was from 1939 to 1945, range 6 - 9 MHz and transmitter RF output about 0.25W, not really enough for a decent RF burn.