This analog meter circuit was found in the September 1989 issue of Radio Electronics magazine. The source must be dual, and the table gives the resistors for the various scales.
This oscillator with crystal for overtone operation was found in an old American documentation. The coil...
In the figure we have a basic PLL circuit with the LM567 or equivalent. The circuit is from a 1977...
The A3906 integrated circuit from Allegro MicroSystems (www.allegro.com) consists of a single...