This high-impedance probe for oscilloscopes was found in a July 1958 Radio Electronics magazine. The circuit did not include a power supply.
The ZN414 integrated circuit consists of a complete radio from the 1980s. This single receiver...
This variable high pass filter covers the range from 23 Hz to 700 Hz with the components used. The...
This circuit is from documentation from Analog Devices from the 90s. The circuit uses operational...