Tachometer, Electrical, 12,000 RPM, Luftwaffe Fl.20266 Drehzahlanzeiger Aerial Refueling and 3 inches by 3

and 3 inches by 3

and was made by Hartmann & Braun

The knob situated below the display rotates to oil reservoir 1 thru 4 (see photo of display partially rotated)

Tactical Use of B-29 Equipment

Briefly stated

Tachometer, Electrical, 12,000 RPM, Luftwaffe Fl.20266 Drehzahlanzeiger Aerial Refueling and 3 inches by 3Here is a nice specimen of a WWII era electrical Switchable Tachometer, or Drehzahlanzeiger, as used in versions of the German Luftwaffe jet aircraft Me 262, He 162, and Ar 234. This tachometer received electrical signal from a generator located proximal to the engine drive to indicate engine speed, from 1,000 12,000 RPM. According to our friends at DeutscheLuftwaffe: Since the Jumo 004 engines were only reliable up to approx. 9,000 rpm, the