Coaxial cable was invented in 1880 (yes, the 1880s) and has been carrying high-frequency electrical signals ever since. Despite the rise of fiber optic and wireless technologies, coaxial cable remains essential infrastructure for cable TV, satellite TV, internet service, antenna connections, and security camera systems.
If you've ever screwed a cable into the back of a TV or modem, you've used a coaxial cable. Here's what RG6, RG59, RG11, and the various connector types mean.
What makes a cable "coaxial"?
The "coaxial" in coaxial cable refers to the shared central axis of the cable's components. From the inside out, every coaxial cable has:
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Center conductor — A solid copper or copper-clad steel wire carrying the signal
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Dielectric insulator — Plastic or foam separating the center conductor from the outer shield
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Outer shield — Braided copper, aluminum foil, or both, surrounding the dielectric
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Outer jacket — PVC or polyethylene protecting the cable from physical damage
The geometry creates a controlled-impedance transmission line that can carry very high-frequency signals (up to several GHz) over long distances with minimal loss or interference.
RG numbers explained
The "RG" prefix stands for "Radio Guide," a US military spec from World War II. The numbers identify specific cable constructions with defined electrical properties. While the original RG specifications are obsolete, the names have stuck.
RG6 — The standard coaxial cable for residential cable TV, satellite TV, and broadband internet. Has a 75-ohm impedance and uses a thicker center conductor (18 AWG) than RG59. Quad-shielded RG6 is often used for satellite installations to reduce interference.
RG59 — Older, thinner coaxial cable with a smaller center conductor (20-22 AWG). Originally used for cable TV and CCTV. Now mostly used for short CCTV runs and audio applications. RG59 has higher signal loss at high frequencies than RG6, making it unsuitable for satellite or HD cable TV.
RG11 — Heavier-duty coaxial cable with a larger center conductor (14 AWG). Has lower signal loss than RG6 over long distances. Used for long cable TV runs (300+ feet), commercial installations, and as a "trunk" cable feeding multiple RG6 drops.
RG58 — 50-ohm coaxial cable used for radio applications, ham radio, and older Ethernet (10BASE2 "thinnet"). Different impedance than the 75-ohm cables above.
RG174 — Thin, flexible 50-ohm cable used for short antenna jumpers and high-frequency test equipment.
F-type connector — The cable TV standard
The F-type connector is what most people picture when they think of coaxial connectors. It's the screw-on connector with the threaded outer shell that you use to connect cables to TVs, modems, and satellite receivers.
F-type connectors come in two varieties:
Compression F-connector — Used by professional installers. Requires a special crimping tool. Provides the best weatherproofing and signal integrity. Used in outdoor installations, satellite work, and any installation that needs to last decades.
Screw-on F-connector — Twists onto the cable using just hand tools. Easier to install but less reliable, especially outdoors. Generally fine for indoor cable TV connections.
The F-type connector is by far the most common coaxial connector in residential applications. Cable internet, satellite TV, antenna feeds — they all use F-type.
BNC connector — The professional standard
BNC connectors (Bayonet Neill–Concelman) use a quarter-turn twist-lock mechanism instead of screws. Push and twist 90 degrees, and the connector locks in place.
BNC connectors are the standard for:
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Professional video — SDI (Serial Digital Interface) connections in broadcast and production equipment
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CCTV systems — Most analog security cameras and DVRs use BNC
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Test equipment — Oscilloscopes, signal generators, frequency counters
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Older Ethernet — 10BASE2 used BNC connectors
BNC connectors are faster to connect/disconnect than F-type and lock more securely than screw-on F-connectors. They're used in environments where the cable might be moved frequently or where vibration could loosen a threaded connection.
Other coaxial connectors
N-type — Larger, threaded connector used in microwave applications, cell tower equipment, and some marine electronics. Designed to be weatherproof.
SMA / SMB / SMC — Small connectors used in RF test equipment, antennas, and some networking gear (Wi-Fi access point external antenna ports often use SMA).
RCA (yes, the same RCA from audio/video cables) — Sometimes used for digital coaxial audio signals (S/PDIF) and component video. Same physical connector as composite audio/video, but with the cable impedance-matched for the application.
TV antenna F-type vs IEC (PAL) — In the US, TV antenna and cable connections use F-type. In Europe and other regions, the IEC 169-2 (PAL) connector is standard — a different shape entirely.
Common coaxial applications
Cable TV — F-type connectors, usually RG6 cable. Modern HD cable boxes need quality RG6 (not RG59) for reliable signal.
Satellite TV — F-type connectors, usually quad-shielded RG6. Higher frequencies than cable TV require better shielding.
Cable internet — F-type connectors, RG6 cable. DOCSIS 3.1 and 4.0 modems use the same physical cable as cable TV.
Over-the-air antennas — F-type connectors, RG6 cable from antenna to TV.
CCTV security cameras — BNC connectors with RG59 (analog cameras) or RG6 (longer runs). Modern HD-SDI cameras need quality RG6 with proper impedance matching.
Ham radio / two-way radio — Often uses 50-ohm RG58 with PL-259, BNC, or N-type connectors depending on the equipment.
Buying coaxial cables
For most residential applications, RG6 with screw-on F-connectors is fine. For longer runs (over 100 feet), more demanding applications (4K satellite), or outdoor installations, look for:
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Quad-shielded RG6 — Two layers of foil + two layers of braid for maximum interference rejection
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Solid copper center conductor (not copper-clad steel) for better long-distance performance
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Compression F-connectors if installing outside or in walls
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UL listed jacket for in-wall installations
For BNC applications, quality matters more — cheap BNC connectors can develop loose contacts and cause intermittent video issues. Look for connectors from established manufacturers like Amphenol or Belden.
At Kentek, we carry coaxial cables in RG6, RG59, and RG11 with F-type and BNC connectors, in lengths from 3ft to 100ft. All cables use solid copper conductors and quad-shielded construction.