Radar Indicator, CS-55ACE, ASD Surface-Search, WWII US Navy Eurofighter Typhoon See photo of the location

See photo of the location of the instrument on the Flight Engineers upper instrument panel from the C-121 flight manual dated 1958

the gyro produced vertical attitude signals which were amplified and transmitted to the autopilot system and indicators on the flight deck of the aircraft

but it is there and shows the spec # and serial #)

It has a calibration mechanism

electrical input is required to test its full functionality

Radar Indicator, CS-55ACE, ASD Surface-Search, WWII US Navy Eurofighter Typhoon See photo of the locationThe indicator is a CS 55ACE indicator for a WW2 US Navy Type ASD surface search radar system. The ASD was the first effective American microwave search radar, and was used in aircraft such as the US Navy's Patrol Bomber Lockheed PV 1 Ventura, PV 2 Harpoon, and Grumman TBF Avenger. Researching the internet reveals that Type ASD X band airborne search radar used this indicator as a B scope (range vs bearing) in US Navy patrol aircraft to detect ships