Found in a September 1972 Radio Electronics magazine, this circuit uses RCA's CA3020, a multi-purpose amplifier in a round metal 12-pin package.
Other series amplifiers such as the MC3301, MC3401 and LM2900 can be used on this circuit. We...
Crystals from 100 kHz to 1 MHz can be used in this 1957 Raytheon circuit. 4 can have values...
This window comparator configuration is from a 1980 publication. It is a conventional circuit that...