How to Build an FM Antenna Out of Coat Hangers
FM radio signals are directional, so tuning in weak signals can depend to a great deal on the antenna you're using to tune them in. The simple dipole antenna design is easy to make from basic materials and provides a big step up in performance from a simple wire antenna. In addition, it can be positioned so that it can optimally tune in weak stations. You can make one of these out of quite simple materials.
Things You'll Need
- Coat hangers
- Wire cutters
- Needle nose pliers
- Sheet metal screws
- Cable staples
- Matching transformer
- Coaxial cable with F-type connectors
- FM receiver with antenna input
Cut and straighten two lengths of coat hanger wire so that you have two straight wires that are each 52 inches in length. A pair of pliers and a pair of wirecutters will make this easier than bending with your hands alone.
Make a small U-shaped loop on one end of each wire with a pair of needle-nose pliers. Sand the metal around the loop ends of the wires with medium-grit sandpaper to remove any paint or plastic coating on the wire.
Cut a rectangular piece of plywood, measuring 1 by 12 inches, with a saw. In the center of the board, screw in two 1/2-inch sheet metal screws until they are about 1/4 inch into the wood.
Loop the U-shaped ends of the wires over the screws so that they're positioned underneath the head of the screw–one wire per screw, with the wires parallel to the long side of the rectangular piece of wood.
Hammer a cable staple into the wood block, pinning the wires into position on the block. This prevents them from slipping out of position during use.
Slide the U-shaped tabs of 300- to 75-ohm matching transformer under the sheet metal screws on the wooden block, one per screw. Then tighten down the screws with a screwdriver until the ends of the wire and the transformer tabs are firmly held together against the wood block.
Connect a coaxial cable to the other end of the matching transformer by screwing the cable's F-type connector into the transformer. Connect the coaxial cable to the FM receiver, turn the receiver on and position the antenna so that it provides the best signal.
Tips & Warnings
- When positioning your antenna, remember that "high and clear" is best–high off the ground, and clear of any obstructions.