This transmitter for the 3.5 and 7 MHz ham radio was found in a 1950s Japan publication. No information was given on the coils and the power supply.
This circuit was found in a 90s Popular Electronics. The circuit uses components from that time,...
Found in a 1966 General Electric manual, this circuit provides a delay in starting. The motor is...
The transistors can be the BC548 and BC558 and the operational can be a 741. The circuit is from...