Adjustable reference (CB21540E)

We found this circuit with 5.3V zener in a Philips publication from the 60s. The op amp could be a modern equivalent.

Infrared alarm (CB7238E)
Found in 1968 Mullard documentation, this circuit uses period components. The transistors are...
Voltage Multiplier (CB20184E)
In the figure we have a modified multiplier circuit that can operate with the sextuplicator with...
Low frequency converter (CB9336E)
This circuit converts signals from the 350 to 500 kHz band to the 4.36 to 4.5 MHz band, enabling...