This Japanese radio is from the 60s, presenting excellent sensitivity and an output power of 100mW with 6 V power from ordinary batteries. The circuit is of the superheterodyne type.
We found this circuit in a Popular Electronics from 1992. It consists of a voice scrambler used in...
This circuit already uses an integrated circuit from the time. Note the different encapsulation of the...
Found in a 1960s documentation, this circuit uses an operational amplifier from the time and a...