Don't forget to cover it with heat-shrink tubing. Radio Shack has some. Get a length that is about twice the diameter of the wire, slide it on over, and hit it with your heat gun. It will shrink right down to the proper size and it will be good and tight.

Remember, don't just twist the wires together, they have to be soldered. You can twist the wires together then hit heat the wire with a soldering iron, then touch it with the solder. It will flow into the twisted wires and set up perfectly. This does not require a lot of skill to do. You can practice on some spare wire to make sure you got it right then do it on your antenna wire.

And, as Ken said, make sure it's the right length. Longer or shorter will not work well. That will reduce your range. And, as mentioned, range check before flying.

CGr.