This is the typical circuit of a local oscillator for a superheterodyne FM receiver. The circuit was found in a 1980s documentation and is typical of early and early receivers.
This amplifier was found in an 80s component manual. The circuit can be used for media recovery....
This is a bridge for the measurement of low value resistances and high values too. The circuit...
This digital mixer uses CMOS integrated circuits. The circuit was published by us in a magazine...