This receiver for the AM band with 6 transistors was manufactured in the 60's in Japan. The power is made with 9 V and the circuit is of the super heterodyne type with FI of 455 kHz.
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...