Wi-Fi Antenna Wire: Connect Radio to Antenna

Updated 14 November 2026 · Standard formula, shown below

Connecting a Wi-Fi antenna wire to your radio (router or adapter) is a straightforward task that improves signal strength and stability. This guide covers the physical connection, whether you’re replacing a damaged cable, extending an antenna, or installing a new one. You’ll need the correct cable type, connectors, and basic tools.

What You’ll Need

Wi-Fi antenna cable (typically RG174, RG316, or LMR195) with the correct connectors
RP-SMA or SMA connectors (male/female as required by your device)
Wire strippers or a sharp knife
Crimping tool (for connector installation) or pre-made cable
Soldering iron and solder (if not using crimp connectors)
Multimeter (optional, for continuity testing)
Heat shrink tubing or electrical tape

Step-by-Step

Identify the connector type on your radio. Most Wi-Fi routers and adapters use RP-SMA (Reverse Polarity SMA) female connectors. External antennas typically have RP-SMA male. Check the label or look at the center pin: if there’s a hole in the center of the connector on the device, it’s RP-SMA female; if there’s a pin, it’s SMA female.
Choose the correct cable. Use a low-loss cable like LMR195 for runs under 10 feet, or LMR400 for longer runs. The cable must have the correct connector on the radio end (RP-SMA male for most routers) and the antenna end (usually N-type or RP-SMA).
Prepare the cable (if making your own). Strip the outer jacket about 1/4 inch (6 mm) from the end. Carefully trim the braided shield so it’s flush with the jacket. Strip the inner dielectric (insulation) about 1/8 inch (3 mm) to expose the center conductor.
Attach the connector to the cable. Slide the connector’s outer shell over the cable first. Then push the center pin onto the exposed conductor and crimp or solder it. Slide the shell up and crimp the ferrule onto the braided shield. Ensure no stray wire strands touch the center pin.
Connect the cable to the radio. Align the connector’s keyway with the radio’s port. Screw it on clockwise until finger-tight. Do not overtighten; use a wrench only if necessary, and hold the radio’s connector with another wrench to avoid stress.
Attach the antenna end. Screw the antenna onto the other end of the cable, again finger-tight. If the antenna has a pivot joint, position it vertically for best performance.
Route the cable safely. Avoid sharp bends (minimum radius about 10 times the cable diameter), pinching, or running alongside power cables. Use cable clips or ties to secure it without crushing.
Test the connection. Power on the router and check the Wi-Fi signal strength on a device. If it’s weaker than before, check for loose connections or damaged cable.

Common Mistakes

Using the wrong connector type. Mixing SMA and RP-SMA will not fit or will damage threads. Always verify.
Overtightening. This can strip threads or crack the connector. Finger-tight plus a quarter turn is usually enough.
Poor cable routing. Sharp bends or kinks increase signal loss and can break the center conductor.
Leaving exposed shield touching the center pin. This causes a short, degrading signal or damaging the radio.
Using a cable that’s too long. Every foot of cable adds loss—keep it as short as possible.

Tips

Use a pre-made cable with connectors already attached if you’re not comfortable with crimping or soldering—it’s more reliable.
If you’re extending an antenna, place the antenna as high and as clear of obstructions as possible.
For outdoor installations, use weatherproof connectors and seal with silicone tape or a weatherproof boot.
Label the cable ends (e.g., “radio” and “antenna”) to avoid confusion during setup.
Test with a multimeter: the center pin should have continuity with the center conductor, and the outer shell with the shield, but no continuity between center and shell.

Troubleshooting

No signal or very weak signal: Check all connections are snug. Verify the cable isn’t damaged (visually and with a multimeter). Try a different cable if possible.
Signal works but drops intermittently: Likely a loose connection or a cable that’s being flexed. Tighten, and consider a strain relief.
Connector won’t screw on: Check for cross-threading or wrong type (SMA vs RP-SMA). Do not force it.
Radio doesn’t recognize the antenna: Some routers have a detection pin; ensure the connector is fully seated. If the antenna has an amplifier, make sure it’s powered.
Signal is worse than before: The cable may be too long or of poor quality. Try a shorter, higher-quality cable. Also, ensure the antenna is oriented correctly (usually vertical).

Frequently Asked Questions

What’s the difference between SMA and RP-SMA?

SMA has a male pin on the plug and a female socket on the jack. RP-SMA reverses this: the plug has a socket, and the jack has a pin. Wi-Fi gear commonly uses RP-SMA to prevent connecting standard antennas.

Can I use a TV coax cable for Wi-Fi?

No. TV coax uses different impedance (75 ohms) and connectors (F-type). Wi-Fi needs 50-ohm cable and specific connectors. Using the wrong cable will cause signal loss and may damage the radio.

How long can the antenna cable be?

It depends on the cable type. For RG174, keep it under 3 feet; for LMR195, up to 10 feet; for LMR400, up to 30 feet. Longer runs require thicker cable to minimize loss.

Do I need to solder the connector?

Not necessarily. Crimp connectors are reliable if you have the right crimping tool. Soldering is also fine, but avoid cold joints. Pre-made cables are easiest for beginners.

Why does my router have two antenna ports?

Many routers use MIMO (Multiple-Input Multiple-Output) for better speed and range. Each port handles a separate data stream. Connect antennas to all ports for best performance.

Can I connect two antennas with a splitter?

No, a splitter divides the signal and increases loss. Instead, use a router that supports multiple antennas or use a single high-gain antenna.

Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.