In this interesting circuit from Popular Electronics, the output voltage is the square root of the input voltage. Equivalent operational amplifiers can be tried out.
This 25 W phase photo control was found in a 1965 General Electric publication. The circuit uses a...
The circuit below uses common JFET transistors, which can be the BF245 or MPF102 amplifying video...
This circuit was found in a 1997 documentation. It works as a booster for VHF and UHF signals...