This circuit generates rectangular signals from 2 Hz to 20 kHz using an operational amplifier. The circuit is from 1984 Radio Electronics. The power supply must be symmetrical.
Suggested by Motorola documentation from the 1980s, this circuit can be implemented with...
This oscillator reaches 50 MHz with an overtone crystal. The circuit is from Electronics Now...
This modulator circuit for low intensity signals is from old documentation. The integrated circuit...