This circuit can be used as an answering password system in a store, office, or other location. The circuit is from Intersil using components of the time. The circuit is from the 80's.
This oscillator was obtained in a 1960 transistor manual from Sylvania. The transistors are from...
This sensitive MW receiver was found in a publication of year 1958., The circuit uses germanium...
This circuit for crystals from 100 to 500 kHz was found in an American documentation from 1954. The...