Data Hacking

84 Part I — Hardware Hacks
FIGURE 4-19: Partly completed helix coil
8. Continue winding all the way to the top, taking care that the coils are equally spaced
and smooth, and add hot glue to keep it in place as you go. When you get to the top,
pass the wire through the hole and back inside the tube. Use pliers to pull the wire
tightly through the hole, and bend it up toward the top of the pipe (see Figure 4-20).
Secure this in place with more hot glue. Cut the wire off, leaving about 6 millimeters
( 1 ⁄4 inch) from where it makes the turn inside the pipe so it will stay in place.
9. Connect the antenna to the GPS and test it for proper operation.
10. Optionally, glue the cap to the top of the antenna and ensure that all your joints, connectors,
and glued parts are sound.
A diagram of the finished antenna is shown in Figure 4-21.
You can now think about attaching the antenna. No matter what you do, however, don’t attach
anything metallic to the ground plane (use glue or nylon nuts and bolts).
You can add glue some rubber-covered magnets to the base for automotive use. Make sure that
these are strong magnets and test them to see how secure they are.