This circuit that uses a loop antenna was found in a 1924 publication. The circuit has several supply voltages and sets of audio and RF coils.
This oscillator uses a small transistor amplifier or radio output transformer. We found it in a...
This small transmitter circuit has a range of about 100 meters, and the antenna must be connected to...
In the figure we have the way to connect several 555 to obtain sequential operation. The component...