This is a classic FM amplifier IF amplification stage configuration. The circuit is from a 1980s documentation. CN is the neutralizing capacitor.
Found in old documentation, this circuit uses special discharge lamps (neon) of the time. The...
This 1968 Texas Instruments circuit uses diacs of the era. SCRs can be modern equivalents according...
This circuit is designed to measure very weak currents, in the order of picoamperes. We found it...