This circuit is from an American documentation from 1975. The single junction transistors can be 2N2646 and the signal must be applied to the input of a good amplifier.
This 6-transistor transistor radio is a RCA product from the 1960s. The circuit is powered by a 9...
This variable voltage reference uses a Norton operational amplifier. The voltage is adjusted at...
This circuit is from Radio Electronics magazine, November 1974. The supply voltage depends on the...