This circuit is from documentation from 1965 but can be easily implemented today using modern transistors. We can use BD136 for Q1 and TIP42 for Q2. The TIP must be equipped with a heat sink.
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...