This circuit is from Electronics Now magazine, February 1987. The number of channels is high depending only on the distances of the stations and the losses in the cables.
This circuit was indicated in an old American publication to serve as a Laser alarm system as a...
This circuit, which uses only transistors as active components, was found in a 1987 documentation. The...
This sound meter or sonometer was found in a Popular Electronics from the 80's. The circuit can be...