I picked up an AN-29-C collapsible whip antenna this weekend at an Army-Navy store. It extends to 12' 10 3/4" which is a half wave at 37.2 MHz. Does anyone know what piece of gear this is from? There is a cap on a chain which covers the top and it has a threaded stud on the bottom. Looks like a 5/8" thread. Any help is appreciated. 73, Rick kf4ar