Homemade 75 Ohm FM Antenna

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If you have an FM receiver with a jack for an external antenna, you'll note that the jack is usually specified for 75-ohm antennas. If you're unfamiliar with an antenna design, building an antenna that will work at a specific resistance may seem like a difficult task. But it actually isn't--you can build an antenna that works with a 75-ohm input fairly easily and inexpensively.


Step 1

Cut a 30-inch length of 300-ohm twin lead cable. Don't be concerned that the cable is a 300-ohm cable and you're making a 75-ohm cable. The cable is merely used as the active element that receives the signal.

Step 2

Remove 1/2 inch of insulation from the both ends of the cable. Twist together the separate leads at each end of the cable.

Step 3

In the middle of the cable, cut one of the two elements of the cable and remove 1/2 inch of insulation from either side of the cut with your wire strippers.


Step 4

Solder each bare wire from the middle cut to one of the tabs of a 300- to 75-ohm transformer.

Step 5

Connect one end of the coaxial cable to the transformer by plugging it in.

Step 6

Connect the other end of the coaxial cable to the antenna input of your receiver.

Things You'll Need

  • 300-ohm twin-lead cable

  • Wire cutters/stripper

  • Ruler

  • 300- to 75-ohm transformer

  • Soldering iron

  • 75-ohm RG-6 coaxial cable with F-Type connectors


300-ohm to 75-ohm transformers can be bought at most electronics supply shops.