We found the circuit of this Japanese transistorized commercial receiver in a documentation from the 1960s. It is a radio for the medium wave range with 6 transistors and 9 V power.
The basis of this circuit is a CA3130 operational amplifier. The transistor can be BC548, and the...
This circuit, found in a 73 magazine for radio amateurs, is used in radio localization. The...
This circuit is from an American magazine Popular Electronics of March 1991. The circuit produces both...