bought a shorty antenna...cant figure it out?

[smellmygas]

i bought a shorty antenna off some dude on ebay selling a bunch of them, i finally got the stock antenna off for some reason it was a pita, anyways it looks like the base where the antenna screws in doesnt have threads?? for anyone who have gone to a shorty how did u do it? i got 3 adaptors in the package and some black peice.....what am i doing wrong?
please help!

 

[iwashmycar]

If the adaptor thingys are threaded, i think you put in in the bottom of the shorty and screw in same as stock.

My short ant. has a little allen bolt which looks like it may hold an adaptor, but i bought the car with it so i am not sure

 

[Mustang5L5]

Those antennas look ugly to me and they don't really do much for range.

Why not just shorten the stock antenna? Just tap the ball off the end of the antenna, vut the antenna to desired lenght and reattach the ball. Short thin antenna for $0

 

[HISSIN50]

i think there is a tech article floating around somewhere on shortening the antenna the way Mike said.....but since you have this one already....
what do you mean there is no stud coming out of the base? when i did mine, there was a stud hanging out. the new one threaded right on.
are you missing the stud? sorry if i misread what you said....