Step 1: Materials and Tool you need.
-Altoids Can/Base of sorts
-Broken Antenna. A dowel or something similar will do fine, although probably less portable
-Magnets. I used NeoDymium magnets from an old hard drive, they seem a bit TOO strong for this purpose, so I suggest weaker magnets for the base, and maybe, a strong one on the string.
-2 Paper Clips. I made the mistake of making them too long, therefor attracting the pendulum to the antenna. This is OPTIONAL, since hot gluing it will work fine, and probably better, although sacrificing portablility.
-Hot Glue sticks. For gluing the pole's base, use hot glue or somthing strong to hold it togethe.
-Drill. Power drill or hand dril is fine, although use something to make it drill straight, else it'll slide off. Basically, something to make a hole big enough for the antenna/pole to fit through.
-Hacksaw. A power saw is acceptable if your antenna is the strong kind(with layers inside of it so it's thicker), but a hacksaw is great for cheaper, thinner antennas.
-Hot Glue Gun. To attach holder for pole/antenna.
-Marker. Use it to estimate measurement, since there is no true need for a ruler here, you can estimate the lengths you need and it'll work out fine. You can just estimate using your hands too.
-Bench Grinder or File. Cutting the antenna WILL leave the sides roughed up, and you need to file/grind it down or else it'll cut you.