This small analog TV transmitter was found in an Electronics Now from the 90s. The range is around 20 meters, and the coils are according to the channel on which you want to receive the signal.
This circuit was found in an Electronics World of 1968. It can be applied to any modern triac and...
This circuit is from a documentation from the 70s. The transistors are types of germanium of the...
Obtained from a 1996 documentation, this circuit uses common components and has a voltage gain of 200...