[JoeLouie]

U-bolts should work just fine. 3" u-bolts are the perfect size for the foot of a Bell dish. Although, you'll probably have to make the bolt holes just a tad bigger to get the U-bolts through. I'm not sure how well 3" u-bolts will work on a 2.5" pole though.

What is the pole made out of?

 

[JoeLouie]

And yes, what Pinza said. I must have completely skipped over the part that said "It seems to be a type of conduit for electrical wires."