How to Build a Free Homemade FM Antenna for Radio Signals
Listening to FM radio requires a properly constructed antenna for achieving the maximum signal strength for your FM radio receiver. Although many people are able to make due with something as simple as a length of coat hanger, such an attempt isn't truly a "tuned" antenna that is designed to receive FM signals in the most efficient manner. Thanks to one of the many Low-Power FM stations in the United States, WRYR-LP, an extremely well-tuned and accurate FM antenna plan is now freely available and enjoys a wide circulation on the Internet. Though most parts can be purchased, the antenna may be built for absolutely nothing provided you are willing to do a little extra woodwork and a small portion of time scouting.
Things You'll Need
- WRYR-LP tuned FM antenna plan (free PDF via Internet)
- Sharp whittling knife
- Hack saw
- Two four-foot tree branches, dried, cured
- Wood sealer
- Insulated wire, any gauge, 10 AWG preferred for ease of use
- 300-ohm ladder-line coaxial cabling, suitable length from antenna to your radio receiver
- String (optional)
- Duct tape (optional)
- Pliers with cutter
- Wire strippers
- Soldering iron and solder
- Black electrical tape
Obtain a free copy of the WRYR-LP antenna plan circulating on the Internet. The plan provides detailed information on how to properly tune the antenna to your own listening requirements, rather than a "one-size fits all" approach. The plan is in PDF format and may be found either in the references below or via online web search using your favorite Internet search engine.
Find two reasonably straight tree branches, each about four feet long to start. Use a sharp whittling knife and whittle the branches until they are smooth and straight. Use a hack-saw to cut them to the necessary lengths for the frequency range you have determined, according to the formula in the WRYR-LP antenna plan.
Scavenge the recommended length of insulated wire called for by the plans. To obtain this wire for free, watch for discarded electronic appliances that are being thrown away in your neighborhood. The insulated wire may be snipped off of old discarded toasters, lamps, or other appliances. Try to find a length that is long enough so it doesn't have to be spliced together.
Source, for your antenna, a length of 300-ohm "ladder-line" coaxial cabling of a suitable length to run from your antenna to the connectors on the back of your FM radio transceiver. In an effort to keep your antenna system truly free, drive through your city and pay special attention in locating any properties that may have an old outdated television tower with the traditional ladder line dangling alongside it. Ask the property owners if you can have a length of the ladder-line. You may want to consider offering a small token payment as an act of appreciation, but there is free 300-ohm ladder-line coaxial cabling to be had in many communities.
Connect the two whittled brace limbs together, per the WRYR-LP plan instructions. The support brace these two limbs create should look like an "X" and the center can be secured using anything you may have laying around, including a large amount of kite string, duct tape or anything that will hold the center of the "X" securely.
Run your insulated wire around the "X" support brace and secure the wire at the top/bottom of each end of the limb, as the plan demands. Strip the wire ends and, using a soldering iron and solder, solder the ladder-line onto the two ends of the antenna wire: one side of the ladder line to one end and the other side to the other end of the ladder-line. Wrap the bare wire with black electrical tape.
Hang your antenna from a tree or other elevated structure and run the ladder-line from the antenna to the rear of your radio receiver. Connect the ends of the ladder-line to the connector(s) on the back of your particular receiver and tune your dial to your chosen listening frequency.
Tips & Warnings
- Be sure you are obtaining 300-ohm ladder-line cabling when hunting for it. There are two types that have been used throughout history: 300-ohm and 75-ohm. The WRYR-LP design requires 300-ohm ladder-line. Look at the outer insulation of the cable you are about to cut. If it is 300-ohm, you should see the number "300" on the insulation, with an Omega sign after it.
- Ladder-line is also known as "matched" coaxial wire. It looks like a ladder with "rungs" between the left and right wires. If your radio receiver has a round PL-259 antenna connector, rather than two screws to accept ladder-line, you will have to obtain a PL-259 male connector. Solder one end of the ladder-line to the outside of the plug skirt and solder the other wire end to the center pin. Soldering PL-259 instructions have been included in the references below,