Found in a 1965 General Electric Hobby Manual, this timer was originally created to operate with photo magnifiers of the time. The circuit can be adapted for other purposes.
This booster for listening to signals in the range from medium waves to 30 MHz was found in a 1998...
In the figure we show our first circuit that consists of a simple touch switch capable of driving a...
Using a 7400 we have a short-wave transmitter from 4 to 9 MHz, shown in the figure. The coil...