What is wrong with my Camaro's power antenna?

I have a 1986 Chevrolet Camaro IROC Z28, and it has the power antenna option. However, I dont know what is wrong with it, but it goes up and down as usual, but it doesnt go completely down into the fender the way it should. It stops going down about five inches or so from the fender, and pops 3 times before the little motor stops running. Then, when it goes up, it goes all the way up like usual, but then pops 3 times again, before the motor in it stops running once again. It sounds like something is off track maybe, but I don’t know much about the power antennas in the vehicle. Can somebody help me figure out what is wrong, as well as maybe help me fix this, possibly without the costly replacement assembly?