This circuit was found in the January 1991 issue of Radio Electronics magazine. The circuit uses integrated circuits of the time and the coils depend on the tuned bands.
This timing circuit was found in old documentation. The technology is CMOS. The supply can be made...
This circuit was found in a 1967 General Electric documentation. Tunnel diodes can oscillate at very...
This circuit can be used in a signal level indicator with LEDs. The circuit is from an Electronics Now...