[Boatanchors] Unknown coil

[Michael A. Bittner]

Can anyone help me identify what unit this coil was original meant for?  It is 2-inches in diameter by 2.25-inches long and is marked L-107.  It has a coupling coil inside that can be rotated for minimum to maximum coupling via the shaft that projects out at one end at a 45-degree angle.  Its rugged, quality construction suggests a military unit of some kind. 
https://www.dropbox.com/gallery/56278480/1/L-107?h=9e44f3 

Please click on the pictures for full size views.  Mike, W6MAB