What Does a Coax Cable Look Like? How to Identify Coaxial Cable at Home

Published: June 14, 2026

A coax cable is usually a round, somewhat stiff cable with a single center conductor inside. For TV and cable internet, it often has a threaded metal F-type connector with a small center pin. Once you have identified it, the next step is choosing the right type of coaxial cable for the signal and distance. If you are looking behind a TV, cable box, antenna, or cable modem, the coaxial cable is usually the round cable that screws onto a matching threaded port. It looks different from Ethernet, HDMI, USB, and power cables.

Quick Answer

A coax cable usually has these visible features:

Feature	What to Look For
Shape	Round cable, usually thicker and stiffer than many low-voltage wires
Connector	Threaded metal connector on many TV and internet cables
Center pin	One small metal pin in the middle of the connector
Common colors	Black, white, gray, or beige
Common location	TV wall outlet, cable modem, cable box, antenna, satellite receiver

For home TV and cable internet, the most recognizable coax connector is the F-type connector.

Identification Checklist

Use this checklist if you are trying to identify a loose cable at home:

Check	Coaxial Cable Clue
Connector shape	Round metal connector rather than a rectangular plastic plug
Center contact	One center pin or one center socket
Attachment style	Often screws onto the device for TV and internet use
Cable stiffness	Usually stiffer than Ethernet or thin audio cables
Jacket printing	May say RG6, RG59, RG11, 75 ohm, quad shield, CATV, or coax
Port label	Device port may say Cable, ANT, SAT, RF In, or Coax

Do not rely on color alone. Coax cables can be black, white, gray, or beige depending on the installer and jacket type.

Where You Usually See Coaxial Cable

Coaxial cable is common in home entertainment and internet setups.

Place	Why Coax Is There
Behind a TV	Connects TV antenna, cable box, or wall TV outlet
Cable modem	Brings cable internet signal from wall outlet to modem
Wall cable outlet	Connects the home to cable TV or broadband service
Satellite receiver	Connects satellite dish signal to the receiver
Outdoor antenna	Carries over-the-air TV signal indoors
CCTV system	Carries video from camera to recorder in older systems

If a cable screws onto a round threaded jack, it is very likely coaxial cable.

How to Identify an F-Type Coax Connector

The F-type connector is the standard connector for many TV, cable modem, satellite, and antenna connections. Look for:

A round metal connector
A threaded nut that twists onto the device
A single center pin
A matching threaded port on the TV, modem, wall plate, or cable box

The center pin is often the center conductor of the cable itself. Avoid bending or breaking it, because a damaged center pin can cause poor signal or no connection.

Coax Cable vs Ethernet Cable Appearance

Coax and Ethernet are often confused because both may be used in an internet setup. They are easy to tell apart by the connector, and the networking differences are covered in more detail in the coaxial cable vs Ethernet cable guide.

Feature	Coaxial Cable	Ethernet Cable
Connector	Round metal connector, often threaded
Plug shape	Circular
Contacts	One center pin
Common cable names	RG6, RG59, RG11
Typical use	Wall outlet to cable modem, TV, antenna
Ethernet connector	RJ45 plastic plug
Ethernet plug shape	Rectangular
Ethernet contacts	Eight small metal contacts
Ethernet cable names	Cat5e, Cat6, Cat6A
Ethernet use	Router, computer, switch, smart TV, access point

If the plug looks like a wider phone-style rectangular plug, it is probably Ethernet. If it screws onto a round threaded port, it is probably coax.

Coax Cable vs HDMI Cable Appearance

HDMI cable is also common behind TVs, but it looks very different from coax.

Feature	Coaxial Cable	HDMI Cable
Connector shape	Round
Connection style	Often screws on
Signal	RF TV, antenna, cable modem signal
HDMI connector shape	Flat, wide, trapezoid-like
HDMI connection style	Push-in
HDMI signal	Digital video and audio between devices

Use coax for antenna/cable/satellite signal paths. Use HDMI between a TV and devices such as a streaming box, game console, Blu-ray player, or cable box.

What Is Inside a Coaxial Cable?

Even though you usually only see the outside jacket and connector, a coaxial cable has multiple layers inside.

Layer	Purpose
Center conductor	Carries the signal
Dielectric insulation	Keeps the conductor centered and separated
Shield	Blocks interference and contains the signal
Outer jacket	Protects the cable

This layered design is why coaxial cable is thicker and stiffer than many ordinary low-voltage wires.

What Does a Coax Wall Outlet Look Like?

A coax wall outlet usually has a small round threaded connector on a wall plate. It may be labeled "Cable," "TV," "SAT," "ANT," or not labeled at all. You connect a coax cable by aligning the center pin with the hole and tightening the connector nut by hand. Do not force the connector if the pin is bent or the threads do not line up.

How to Tell If a Coax Cable Is RG6 or RG59

RG6 and RG59 can look similar. The easiest way is to check the printing on the cable jacket. If you are comparing outside diameter, the coax cable size chart explains the approximate differences. Look for markings such as:

Marking	Meaning
RG6 or RG-6	Common modern TV/internet coax
RG59 or RG-59	Older video or CCTV coax
75 ohm	TV/video/cable-style impedance
Quad shield	Extra shielding layers
CL2, CL3, CM, CMP	Installation rating

If the jacket is not readable, RG6 is usually slightly thicker than RG59, but measuring or reading the label is more reliable.

Common Mistakes When Identifying Coax Cable

One mistake is confusing coax with Ethernet. In cable internet setups, the coax cable connects the wall outlet to the modem, while Ethernet connects the modem or router to network devices. Another mistake is assuming any round cable behind a TV is coax. Some power, audio, and component cables may also be round. The connector is the key: coax usually has one center pin and, for TV/internet, a threaded metal connector. For actual TV replacement cables, use the guide to the best coaxial cable for TV.

What Competitor Guides Often Miss

Many simple identification guides show only a TV coax cable with an F-type connector. That is useful for home users, but it is not the whole category. Coaxial cable can also use BNC, SMA, N-type, RCA, MCX, MMCX, and other connectors depending on the application. For a home user, the most likely coax cable is RG6 or RG59 with an F-type connector. For an electronics technician, radio user, or lab user, a coax cable may be a 50-ohm RF cable with BNC, SMA, or N-type connectors. The cable is still coaxial because of its internal structure, even if the connector looks different from a TV cable.

FAQ

What does a coaxial cable look like?

A coaxial cable is usually a round cable with a single center conductor. For TV and cable internet, it often has a threaded metal F-type connector with a center pin.

What does a coax cable connector look like?

A TV or internet coax connector usually looks like a small round metal nut with one center pin. It screws onto a threaded port.

Is a coax cable the same as an Ethernet cable?

No. Coax has a round connector and usually one center pin. Ethernet has a rectangular RJ45 plug with eight small contacts.

Is a coax cable the same as an HDMI cable?

No. HDMI has a flat, wide push-in connector for digital audio and video. Coax is round and often screws onto a TV, modem, antenna, or wall outlet.

Where is the coax cable on a modem?

On a cable modem, the coax port is usually a round threaded metal connector. It is often labeled "Cable" or "Coax."

What color is a coax cable?

coaxial cables are often black, white, gray, or beige. Color alone does not identify the cable type; check the connector and jacket markings.

For cable types, sizes, TV use, and internet use, see the full Coaxial Cable Guide.

About the Author

MOZ Official Authors

The MOZ Electronics engineering team publishes practical guides on electronic components, connector standards, wireless modules, and procurement best practices for engineers and buyers worldwide.