We found this circuit in the Radio Electronics magazine of May 1977. The circuit has the frequency given by the components according to the formula next to the diagram.
This circuit is from old documentation. The operational amplifier is uncommon nowadays. The...
This memory flip-flop must be powered by 5V voltage. The circuit stores 1 bit. ...
This simple preamplifier was published in Radio Electronics magazine in February 1958. The battery...