This amplifier was found in Burr-Brown documentation from the 90's. The gain can be programmed by resistor Rg as per the table given in the diagram. The power supply must be symmetrical.
This circuit was found in an Electronic Design from 1967. The circuit uses two triacs being T2...
Found in old American documentation, this circuit can use crystals between 27.5 and 33 MHz...
This shield from the 60's uses a germanium transistor of the time and a common type of relay of...