A modern-day update of Sir Douglas Hall’s famous Spontaflex circuit

This updated version of the Spontaflex receiver is presented with a more powerful single i.c. addon audio amplifier, extends coverage through the medium wave band, and uses currently available components that are assembled on printed circuit boards. Using just two transistors, the tuner section retains all of the sensitivity of the original design. The set will receive a.m. and s.s.b. signals.

The receiver is assembled on three separate printed circuit boards, comprising a tuner section, a coil pack, and an audio power amplifier. This arrangement has been adopted so that readers can more easily modify the design to suit their own requirements, or to use coils and an amplifier already to hand.