Gyrosyn Induction Compass / Directional Indicator Sperry 653894 B-52

Here is the Induction Compass (Directional) Indicator for the Sperry Gyrosyn Compass system used in a number of Cold-War-era US Military aircraft such as the B-52 Stratofortress. See location of the instrument in the photo of a B-52 pilots instrument panel taken at Castle Air Museum. The knob should turn the compass card when depressed, but does not engage.  The case is unattached and can be removed to view the internal mechanism. The electrical connector in the rear has been removed.  Measures 3.25 inches diameter and 9 inches deep.