This circuit with a bargraph scale was found in a 90s Popular Electronics. The circuit measures the intensity of a sound in three scales. R14 works as a sensitivity adjustment.
This booster for bands up to 30 MHz, depending on the coil, works by approximation. It is suitable for...
This circuit is one of many that we have in our section. It was taken from the Electronics...
This circuit was found in the February 1980 issue of Radio Electronics magazine. The digital...