We found this circuit in a Radio Electronics from December 1963. The circuit combines valves and transistors and has a high input resistance. The circuit is powered by two batteries.
This time base circuit for the oscilloscope was obtained from an Electronics Now from the 90s. The...
This is the traditional configuration of a high-pass filter with an operational amplifier, such as...
Found in old American documentation, this receiver receives modulated infrared signals and...