In the figure we have a basic PLL circuit with the LM567 or equivalent. The circuit is from a 1977 documentation.
This circuit was found in a Popular Electronics from the 90's. The frequencies depend on the...
This alarm with the 555 integrated circuit is from an EDN from the 90s. The circuit directly...
This crystal oscillator produces a signal in the 27 MHz band, depending on the crystal. The...