I have to apologize for the briefness of this page, but I will get around to filling it out in time. The Navy ARD receiver was a niche capability that came out of a certain amount of desperation, as you can see from the equipment. At the same time, it exhibits the best of the technology that was available at the time.
The receiver portion of the system.
The slide tuned antenna. This was mounted on the fuselage of the aircraft so that the stubs protruded through a hole into the windstream,
usually at a 45 degree angle to receive both horizontally and vertically polarized signals. A 6H6 thermionic diode vacuum tube was mounted in the end of the line
to provide diode detection of the signals. Various length stubs were screwed into the open hole
on the left end to match the anticipated frequency range of targets of the particular ferret mission.