Coaxial cable connects in three straightforward steps: identify the port, push the connector straight in, and twist clockwise until snug
Coaxial cable — the thick cable with a metal connector on each end — carries TV signals, internet, and sometimes phone service into your home. The connector looks like a small metal tube with a pin in the center. To connect it, you push the connector straight into the port on the back of your device, then twist the outer ring clockwise by hand until it stops. You should not need tools, and you should not force it. If it does not go in smoothly, the connector or port may be damaged.
The cable itself does not care which direction it goes — the signal travels the same way either end. But the port on your device does care. Your TV, cable box, modem, or receiver has one port labeled for incoming signal (usually marked "In" or "Cable In") and possibly others for outgoing signal. Always connect the cable coming from the wall to the "In" port.
Key Takeaways
- Push the coaxial connector straight into the port, then twist clockwise by hand until snug — do not force it or use tools.
- Connect the cable from the wall to the port marked "In" or "Cable In", not to any port marked "Out".
- If the connector does not seat smoothly, stop and check whether the pin inside the port is bent or the connector is damaged.
- A loose connection causes pixelation, signal loss, or no picture at all — tighten by twisting the outer ring, not the cable itself.
Where the cable comes from and where it goes
The coaxial cable enters your home through the wall, usually near where your TV sits or where your internet modem lives. It comes from the cable company's network outside. That cable plugs into your modem if you have cable internet, or into a cable box or TV tuner if you have cable television, or into both if you subscribe to both services.
If you have a cable box (the device that lets you change channels and record shows), the cable from the wall goes into the box first. Then a second coaxial cable runs from the box to your TV. If you have a TV with a built-in tuner and no cable box, the cable from the wall connects directly to the TV's "Cable In" port. If you have a modem for internet only, the cable from the wall goes straight into the modem's "In" port.
Some homes have a splitter — a small metal device with one port coming in and two or three ports going out — mounted on the wall or inside a closet. This lets one cable from the street feed multiple devices. If you see a splitter, the cable from the wall connects to the port marked "In", and the cables going to your devices connect to the ports marked "Out".
How to identify the correct port on your device
Look at the back of your TV, cable box, modem, or receiver. You will see several ports. Coaxial ports are round and about the size of a pencil eraser. They have a small hole in the center (where the pin sits) and a threaded ring around the outside. Other ports — HDMI, USB, ethernet — look completely different and will not accept a coaxial connector.
Once you find the coaxial ports, read the label next to each one. The port you need is marked "In", "Cable In", "RF In", or sometimes "Antenna In". Do not connect to a port marked "Out" or "RF Out" — that port sends signal out of the device, not into it. If the label is worn off or missing, check the device manual or the manufacturer's website by searching the model number (usually printed on a sticker on the back).
The connection process step by step
Hold the coaxial cable so the connector is facing the port straight on. The connector should slide in without tilting or angling. Push it straight in until the outer ring touches the faceplate of the device. You should feel light resistance, but not so much that you have to strain.
Once the connector is fully inserted, grip the outer ring (the threaded part) between your thumb and forefinger and twist clockwise. Turn it until it stops — usually about three-quarters of a turn. The ring should be snug enough that you cannot easily twist it further by hand, but not so tight that you have to use pliers or a wrench. A hand-tight connection is correct.
If the connector does not slide in smoothly, stop when ready. Do not force it. Check whether the pin inside the port is bent (look with a flashlight), whether the connector itself is bent or damaged, or whether you are trying to insert it at an angle. If the pin is bent, the port may need replacement. If the connector is damaged, the cable may need replacement.
Fixing a loose or damaged connection
A loose coaxial connection causes pixelation (blocky artifacts on the screen), signal loss, or no picture at all. If you see these symptoms, the first thing to check is whether the connector is fully seated and the ring is tight. Grip the outer ring and twist clockwise a bit more. Sometimes a connection loosens over time from vibration or temperature changes.
If tightening does not fix it, disconnect the cable and inspect both the connector and the port. The pin inside the port should be straight and centered. The connector should have no visible cracks, bends, or corrosion. If the pin is bent, you can sometimes straighten it gently with a small tool, but if it breaks off, the port is unusable. If the connector is damaged, replace the cable.
Water damage or corrosion on the connector also causes signal loss. If you see white or green oxidation on the metal parts, the connector may need replacement. Some people clean corroded connectors with a pencil eraser, but replacement is more reliable. Coaxial cables are inexpensive — usually under ten dollars.
When you need a new cable or a different type of connector
Coaxial cables come in different thicknesses and quality grades. The most common for home use is RG-6, which is thick enough to carry strong signals over long distances without much loss. Older homes sometimes have RG-59, which is thinner and loses signal more easily over long runs. If you are running a new cable more than fifty feet, RG-6 is the safer choice.
The connector on the end of the cable is usually an F-connector, which is the standard threaded type described above. Some older equipment uses a different connector type, but F-connectors are universal for modern TVs, modems, and cable boxes. If your device has a different port type, you may need an adapter, but this is rare.
Pre-made coaxial cables come in standard lengths — 3 feet, 6 feet, 12 feet, and longer. If you need a custom length, you can buy bulk cable and connectors and assemble them yourself, but this requires a crimping tool and some practice. For most people, buying a pre-made cable of the right length is simpler and more reliable.
Coaxial cable versus other connection types
Coaxial cable is designed to carry radio-frequency signals — the kind that travel over the air or through cable networks. HDMI cables carry video and audio digitally and look completely different. Ethernet cables carry internet data and have a different connector shape. You cannot use one type in place of another.
If your TV has both a coaxial port and an HDMI port, they do different jobs. The coaxial port receives broadcast or cable TV signals. The HDMI port receives video and audio from a streaming device, game console, or Blu-ray player. You may use both at the same time — coaxial for live TV, HDMI for streaming apps.
Frequently Asked Questions
What if the connector twists but does not tighten?
The threads may be stripped or misaligned. Stop twisting and pull the connector straight out. Inspect both the connector and the port for damage. If the threads look intact, try inserting the connector again, making sure it goes in straight. If it still spins without tightening, the port or connector is damaged and needs replacement.
Can I use the same coaxial cable for TV and internet?
No. The cable from the wall splits at a splitter or enters two separate devices. One cable goes to your modem (for internet), and another goes to your TV or cable box (for television). They cannot share the same physical cable, though they may come from the same line outside your home.
Do I need to turn off my TV or modem before connecting coaxial cable?
No. Coaxial connections are safe to plug in and unplug while the device is powered on. There is no risk of electrical shock or damage. However, you may lose signal briefly while you are making the connection, and the device may take a few seconds to recognize the signal again.
Why does my picture get worse when it rains?
Water can enter the coaxial cable where it enters your home, or moisture can corrode the connectors. Check the point where the cable enters the wall — it should have a weatherproof seal or conduit. If water is getting in, a technician from your cable company can install a proper seal. Corroded connectors should be replaced.
What is the difference between a coaxial cable and an antenna cable?
They are the same thing. "Antenna cable" and "coaxial cable" both refer to the same type of connector and signal. The term "antenna cable" is sometimes used when the cable connects to an over-the-air antenna instead of a cable network, but the physical cable and connector are identical.