We found this configuration in a 70s American documentation. The circuit makes use of operational amplifiers of the time. Modern equivalents can be tested.
This circuit of old documentation is based on an operational amplifier that is no longer used...
This configurable CMOS configuration for frequencies up to a few megahertz was obtained in an...
This circuit is from a 1968s Motorola documentation. The load can range from 10 to 100ohm and the...