This 1980s circuit was found in Motorola documentation. The circuit uses period components that admit of equivalents. Light feedback in a modern version can be done by optical fiber.
This timer circuit was found in a 1980s documentation. The integrated circuit is the 555, which...
This crystal-controlled circuit was obtained from a 1980s documentation. The power supply should be 5...
In the figure we have an IF amplifier step using a MOSFET. The circuit was found in a 1980s...