This circuit with 1% regulation aims at replacing mercury cells. We found it in a 1967 documentation. Transistors can be replaced with modern equivalents.
Found in an old documentation about neon lamps, this circuit has the frequency basically...
This simple standing waveform (ROE or SWR) meter is used to adjust antenna matching with...
This is the traditional configuration of a high-pass filter with an operational amplifier, such as...