No, what is below the U is not electrically part of the antenna, just for support. Still it's wasted when it can be used to build another antenna, you only need enough to connect to the main support. Here it comes, don't say it, you'll leave it there. Just don't come crying to me when the first strong wind bends it over and you can't make another J-pole with bent tubing.
There's something spooky about a large Black woman with 7 pin tube sockets stuck to her forehead.