We find this encoding circuit in an American 1980s amateur radio documentation. The circuit can be implemented with equivalent modern components.
Microchip's MCP6411 Operational Amplifier can operate at voltages of 1.7 V and has a quiescent...
This amplifier for public address was found in English documentation from 1967. The transistors are from...
In its first version this article was written in Portuguese for a Brazilian magazine and...