Actually, if you purchased the top QD, all you need is a standard old CB whip with the standard thread they all have, 3/8x24.
By the way, they're all .2 inches at the base, and contrary to popular belief, every single standard 102 inch SS whip is made by the same company, no matter who's name is one it. What's more, they aren't in the antenna business; they're a machine shop.
Alan, KØBG
www.k0bg.com