The circuit selected is from the 1960 Mullard transistor reference manual. The circuit is powered by a single 1.3 V battery and the transistors are germanium.
The diagram shows a tone control with the LM381 IC. The circuit is from a Radio Electronics from...
Very simple, this radio control circuit for short distances was found in an Electronic Design from...
From an article in Radio Electronics magazine, May 1989, this circuit requires a dual power...