Capacitance hat

This is a device sometimes found at the end of an element. It can be a cross, a disk, a ball, a loop, or just about anything conductive. It makes the element behave as if it is longer, maybe 10%-30% longer than it really is. It can save space with almost no drop in performance. Capacitive hats are uncommon in TV antennas. (The Channel Master 3671B has six capacitive hats.)