Based on Texas Instruments documentation, this circuit serves for sensor interfacing. The circuit is based on the LF411, but other operational ones can be used.
This simple field strength meter was found in a 1967 documentation. The transistor is germanium, and the...
This is yet another version of the light-controlled oscillator that can be found on this website. This...
Found in a 1969 documentation, this circuit for the 20 MHz band does not use a transformer. The circuit is...