This TTL heads or tails circuit was found in the July 1973 Radio Electronics magazine. The LEDs are types of the time. Note the symbolic representation of this component.
This oscillator was found in the November 1986 issue of Radio Electronics magazine. The frequency...
This sophisticated circuit with a low, medium, and high treble filter is from 1990 documentation. The...
This circuit was obtained from a 1998s Popular Electronics. The magazine no longer exists, but the...