Using the 723 integrated circuit, this power supply has the voltage determined by R2 and R3, which can be changed. The circuit is from a Radio Electronics magazine from July 1971.
August 2017 - Mouser Electronics is announcing the availability of TDK ICS-52000 microphones with...
This circuit, which can be used as a shield or in other applications, can be found elsewhere on...
This crystal or galena radio was found in documentation from the 1990s. The earpiece must be a...