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.
This circuit is from a 1976 Motorola CMOS manual. It can be implemented with modern Darlingtons like...
In the figure we have the way of modulating or controlling the frequency of a relaxation...
The purpose of this circuit is to monitor the operation of an alternator in cars with a 12 V...