This minHour teaches you how to create your own FM antenna in order to increase your FM receiver's range. Depending on your preferred range, you can do this by using either coaxial cable or speaker wire.
Using a Coaxial Cable
Gather the necessary materials.
In order to make a vertical antenna from a coaxial cable, you will need the following materials:
- 50 ohm (or 75 ohm) coaxial wire with copper shielding
- FM receiver with a coaxial connector
- 3/8-inch copper tubing
- Wire cutters
- Hacksaw
- Soldering equipment
Calculate the length of your antenna.
This will determine both how much of the coaxial cable you have to strip and how long your copper tubing should be:
- Divide 468 by the frequency to which you want to connect (e.g., 468/108MHz would become 4.3).
- Divide the resulting number by 2 (e.g., 4.3/2 would become 2.15).
- Multiply the resulting number by 12 inches (30.5 cm) to find the antenna length (e.g., 2.15*12 inches would become 25.8 inches).
Cut off one end of the coaxial cable.
While you’ll want to leave one end of the coaxial cable intact in order for it to serve as the connector, the other end will need to be removed.
- You can use your wire cutters or a hacksaw to do this.
Strip half of the antenna’s overall length from the end of the coaxial cable.
You’ll need to remove each layer of shielding until you arrive at the white layer surrounding the coaxial cable itself.
- For example, if your antenna is supposed to be six inches per your calculations, you’ll remove three inches of shielding.
- You’ll need to remove the copper shielding during this process. The easiest way to do so is by making a shallow incision with the hacksaw all the way around the shielding and then attempting to strip it off from there.
Cut the copper tubing to half of the antenna’s overall length.
The copper tubing will comprise the other half of your antenna’s receiver, so it should be the same length as the section that you just stripped.
- Again, if you’re using a six-inch antenna, the copper tubing will be three inches.
Attach the tube to the coaxial cable.
Slide the copper tubing onto the coaxial cable’s stripped end, then slide it down to the
Solder
You can do this by removing the PVC (black) shielding from around an inch of the coaxial cable directly below the unshielded part, peeling it back with a pair of pliers to form a lip, and then using your soldering pen to connect the lip to the copper tubing.
Connect the coaxial cable to your audio receiver.
The remaining coaxial connector should plug into the receiver’s coaxial antenna port, which makes the rest of the antenna placement fairly simple.
Place the antenna.
Once the antenna is plugged in, angle it toward the nearest station and secure it in place if necessary.
- The fewer obstructions between your antenna and the nearest FM station, the stronger your signal will be.
- Your coaxial cable may be stiff enough to stand on its own without needing support, but you can use stables or any adhesive to prop up your antenna as needed.
Using Speaker Wire
Understand when to use this method.
If your connection to an FM station is mostly fine but requires some fine-tuning from time to time, you can use speaker wire as a quick range-extender to improve the quality of your connection.
- Speaker wire is not an ideal solution to long-range issues. If you’re having trouble receiving a signal at all, you should try using coaxial cable instead.
Gather the necessary materials.
In order to craft a crude antenna from speaker wire, you’ll need the following items:
- 10 feet of speaker wire
- FM receiver with clamp-and-hold (or post) FM connections
- Wire strippers
Split three feet of the speaker wire.
Using a knife or a pair of pliers, separate the top three feet of the speaker wire tubes from each other. You should be left with three feet of spit wire and seven feet of intact wire.
Arrange the speaker wire to form a “T” shape.
You’ll do this by bending each of the split wire ends at a 90-degree angle to the seven-foot section of wire.
Strip the bottom two inches of insulation from the speaker wire.
Use the wire strippers to do so. This will expose two bare wires at the bottom of the “T” shape.
Find your receiver’s antenna connections.
These two connections will normally be marked “FM EXT” or “ANT EXT”, but you’ll almost always see “FM” somewhere near the connection; you should also see the word “Balanced” or “BAL” near the appropriate connections.
- FM receivers can have either clamp-and-hold connectors or post connectors. Clamp-and-hold connectors resemble literal clamps, while post connectors resemble knobs with exposed metal between them and the receiver itself.
Connect the bottom of the “T” to the receiver.
Use each of the exposed wires at the bottom of the “T” shape to connect to each of the FM connections.
- If there’s only one FM connection, you can twist the two bare wires at the bottom of the “T” together to form one wire that can connect to the clamp or post.
Place the antenna.
Ideally, you’ll place your antenna as high up and as close to the nearest station as possible. In some cases, this may mean threading your antenna along the top of a wall, or even running it outside.
- You may have to move the FM receiver in order to make this possible.
Tips
- Both antennae constructed here are “balanced” and will be inconvenient to connect to the typical “unbalanced” telescoping antenna.
- Coaxial cables and speaker wire are both fairly cheap. If you already have the proper tools to create your preferred antenna, you can make an antenna for a fraction of the price of purchasing a new FM antenna.
Warnings
- Antennae that are placed outdoors should have weatherproofing measures (e.g., waterproof coating) in place.
- If your antenna is placed outside, you should implement some form of lightning protection.