This 80's Exar circuit has a carrier detector for frequencies up to 500 kHz. The circuit uses a company 567 which is still a common component.
Found in old documentation, this circuit uses components that are still common on the market. The...
This circuit is from a 1968 publication. Here we have several types of resistive sensors with...
This traditional 3-channel mixer configuration with FET appears elsewhere on this site. The FET...