Master Compass Indicator, Flux Gate Compass System AN5752-2 P-38 the knob adjusts the index

the knob adjusts the index pointer for mach speed along the perimeter of the mach speed scale

The dial markings are clear and the glass and case are intact

when it asked that the AN/APG-3 radar (being developed for the tail defense of the B-36) be adapted to the Northrop F-89

As an offshoot of this equipment Ryan have also developed a helicopter hovering aid (AN/APN-97) which presumably uses Doppler signals to tell the pilot whether or not his machine is stationary above ground or sea

boost indicator

Master Compass Indicator, Flux Gate Compass System AN5752-2 P-38 the knob adjusts the indexThe Master Compass Indicator AN5752 2 was an integral component of the WWII era Bendix Gyro Flux Gate Compass System used in aircraft such as the B 17, B 24, and B 29. The 7 component Flux Gate Compass system was designed to provide accurate navigational guidance using the earth's magnetic forces by minimizing interference from the systems of the aircraft, such as its turrets, guns, and engines. A flux gate gyro transmitter typically located within