This circuit provides signals in phase with the input and with the phase inverted. The circuit was found in documentation from the 1990s. Transistors are commonly used.
This transmitter can be mounted in an extremely small box, especially if SMD components are used....
The basis of this circuit is the 723 integrated circuit, not very common today. We obtained this...
Using LM3909 integrated circuits, this circuit was found in an American documentation from the...