We found this circuit in an American publication from 1977. The circuit drives two LEDs according to the control of the inputs. The technology is TTL requiring 5 V to power supply.
This circuit for the 3.5 MHz band (80 meters) was found in an old radio amateur documentation. The circuit...
This circuit was found in a May 1981 Radio Electronics magazine article. The circuit is offset...
This circuit was found in a 90s Popular Electronics. The circuit operates in the range determined...