Radio Compass Indicator I-81-A of SCR-269-G and AN/ARN-7 Bf-109 such as the P-38 Lightning

such as the P-38 Lightning

an exceptional example indeed

equipped with twin J-34 engines

The center knob rotates a flexible shaft connected to a rotatable loop antenna

This heavy 8 inch metal calculator was first used during WWII in bombers such as the Lancaster

Radio Compass Indicator I-81-A of SCR-269-G and AN/ARN-7 Bf-109 such as the P-38 LightningThe I 81 A Radio Compass Indicator (aka Pilot's Bearing Indicator) is a component of the Radio Compass SCR 269 G system (which evolved into the AN ARN 7), used during WWII. According to the Airborne Radio Equipment Handbook of the Air Service Command dated 1943, this system appeared in versions of the US Army Air Force bombers B 17, B 24, B 25, B 26, B 29, and transports C 46, C 47, and C 54, as well as in any models of these aircraft used by the US