We found this circuit in a 90s Radio Electronics. The circuit generates frequency-modulated 220 kHz signals. The components used are still common.
This mixer uses only four passive component and can be used with high impedance sources. The input and...
This circuit was found in a Popular Electronics of the 90s. The resistor R4 determines the load...
This circuit was found in an American 1980s documentation. The transistors admit equivalents and the...