This Vox circuit uses a specific Motorola component. We found the circuit in the 1990 Linear Databook of the same company. The transistor must be in accordance with the switched load.
This circuit was found in the December 1957 Radio Electronics magazine in the patent section. It...
The integrated circuit used is equivalent to the 555 and the transistor can be the BC558. R1 and...
This configuration, which requires a symmetrical power supply for the 741, can be implemented with other...