The TACANS of my day I seem to remember as linear antenna line radiators on a rotating cylinder. I’m probably wrong and I could very well be just full of sh!t... Navaids wasn’t my specialty. I’m just a dumb ass country boy my wife tells me. :0)
https://en.wikipedia.org/wiki/Tactical_air_navigation_system
http://www.rfwireless-world.com/Terminology/difference-between-DME-and-TACAN.html