Control Unit C-4, of ARN-7 Automatic Radio Compass, B-17, B-24, B-29
Here is a WWII-era Control Unit for the ARN-7 Automatic Radio Compass system used for direction finding and homing. The receiver function tunes from 100-1750 kHz across 4 bands, which were selected by rotating the center knob below the frequency band window. The center knob rotates a flexible shaft connected to a rotatable loop antenna.
The ARN-7 system (see diagram), were one of several generations of radio navigational systems installed in an aircraft such as the heavy bomber B-24 Liberator, B-17 Flying Fortress, B-29 Superfortress, and medium bombers and transport aircraft.
The unit is in reasonable cosmetic condition and all mechanical features appear to operate. The rear panel is absent and 3 sides have slight indentations, see photos. One internal component has a date stamp of 1944. Measures ~8 inches square by 4 inches deep (including tallest knob). A very cool item to add to your collection.