Altimeter, Tyco, 20,000FT, WWI to 1920's US Navy Japanese model 8DJ28AAN

model 8DJ28AAN

This remote tuner was typically positioned within arms length distance of the pilot in order to mechanically tune the receiving radio to the desired frequency

Truth be told

as well as a hand-written electrical diagram

AN/ARN-30 was used in versions of the following aircraft: UH-1

Altimeter, Tyco, 20,000FT, WWI to 1920's US Navy Japanese model 8DJ28AANHere is an Altimeter used in early military aircraft of the US Navy, very similar to the Type C altimeter used by the Army Air Service from WWI thru 1926. Crudely measured altitude from 0 20,000 ft, which was pretty high for aircraft of that era and requiring supplemental oxygen for the crew to exceed ~12,500 ft based upon modern standards. The knob rotates the face of the dial while the pointer remains fixed to set the present field elevation.