Home brew field strength meter I picked up from a junk sale somewhere, cant remember when or where.
It has a Marconi badge on the front, but I do not believe it is a genuine Marconi device, although a number of components were manufactured in the late 1940's early 1950's.
The internal circuit consists of a 0A8 germanium point contact diode, 1K linear potentiometer, an unknown capacitor and an unknown coil as I do not wish to take it apart to find out. If it is not broken, do not fix it! 
