This circuit, with printed circuit board, is from an article in Radio Electronics magazine from May 1971. The circuit uses the C106 which was already a common component at the time.
This circuit was found in a 1967 American documentation. The switching diode (tunnel) used is an...
This sample and hold circuit is traditionally configured and uses an operational amplifier with...
This oscillator with emitter follower was found in an American documentation from the 80's. The...