This sample and hold circuit is from a 1969’s documentation. However, it can be built with modern equivalent components, including the matched pair of transistors.
Found in a 90s 73 magazine, this circuit uses an unusual component today which is the XR2206. |...
This random noise or white noise generator was published in Radio Electronics magazine in July...
This circuit was found in Philips documentation from 1967. The phototransistor is from that time,...