This low-noise, low-drift amplifier was found in a 90's EDN. It can be implemented with modern equivalent operational amplifiers. The font must be symmetrical.
We found this circuit in a 1974 integrated circuit manual. Operational amplifiers can be of...
We found this circuit in American documentation from the 1980s. Transistors can be of general use....
This sophisticated remote field strength meter circuit was found in a 73 magazine for radio...