Control Unit, C-149/ARN-6 Radio Compass System B-36 The instrument is in exceptional

The instrument is in exceptional but experienced condition given its age

but the stamped service date is illegible

Here is an example of a Speedometer of the type used in the WWII-era US Army M-4 Sherman Medium Tank

A description of the system appears in Flight International in January 20th 1938

Control Unit, C-149/ARN-6 Radio Compass System B-36 The instrument is in exceptionalThis is a terrific example of a C 149 Control unit for the aircraft receiver R 101 of the Radio Compass AN ARN 6 system 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 AN ARN 6 system evolved over time, originally using a control box similar