Data Hacking

82 Part I — Hardware Hacks
and mark eight points that are each exactly 4.75 centimeters (1 7 ⁄8 inches) apart (see
Figure 4-17). These have to be as accurate as you can manage because this is key to the
antenna picking up the right frequency.
FIGURE 4-17: Building the helix coil
4. Drill the helix coil base: To do this you can either use a 1 ⁄16-inch bit to drill a hole at the
last mark nearest each end of the helix coil base or you can use an awl to work through
the plastic pipe.
5. Now you are ready to connect the helix wire to the antenna connection. If you are using
a coaxial connector, all you now need to do is solder the end of the wire to the center
of the connector. This will give you a robust and secure connection. If you aren’t using
a connector, then just solder the helix coil wire to the center wire of the cable you are
using. Pass the free end of the wire from the inside of the tube through the hole located
7 ⁄8 inch from the base end of the helix coil base.