Yes, coaxial cables differ in several important ways, and using the wrong type can mean poor signal quality, interference, or a setup that doesn’t work at all. The differences come down to cable thickness, the materials inside, shielding layers, impedance rating, and the connectors on each end. Each of these factors determines what a cable can handle and where it belongs in your setup.
The Main Cable Types: RG59, RG6, and RG11
The “RG” numbers you see on coax cables refer to different sizes and performance levels. The three most common are RG59, RG6, and RG11, and they’re designed for very different jobs.
RG59 is the thinnest of the three, with a 20 AWG (smaller gauge) center conductor and thinner insulation. It works best for low-frequency signals below 50 MHz, which makes it suitable for analog video feeds and older CCTV systems. It loses signal faster over distance and can’t handle the frequencies modern cable TV or internet demand. If you find RG59 already installed in a home, it was likely put in decades ago for basic TV.
RG6 is the standard for most residential installations today. Its larger 18 AWG conductor and thicker insulation allow it to carry high-frequency signals for cable TV, satellite TV, and broadband internet. At 1,000 MHz, RG6 loses about 6 dB of signal per 100 feet, which is acceptable for typical home runs of 50 to 150 feet. If you’re connecting a cable modem, a satellite dish, or a TV outlet, RG6 is almost certainly the right choice.
RG11 is the thickest and best-performing option, losing only about 2.5 dB per 100 feet. That lower signal loss makes it the go-to cable for long runs in large buildings, campus installations, or outdoor trunk lines. The tradeoff is that RG11 is stiffer, heavier, and harder to route through walls. It’s overkill for a typical home setup but essential when cable runs stretch beyond 150 feet or so.
Impedance: 50 Ohm vs. 75 Ohm
Every coax cable has an impedance rating, and the two you’ll encounter are 50 ohm and 75 ohm. These are not interchangeable. Using the wrong impedance creates signal reflections that degrade performance.
75-ohm cable is what you’ll find in nearly all home entertainment and internet setups. It’s optimized for low signal loss, which matters when you’re carrying weak signals from an antenna or a cable provider over long distances. The 75-ohm value also closely matches the natural impedance of a standard half-wave dipole antenna (about 73 ohms), making it a near-perfect electrical match for TV antennas without extra adapters.
50-ohm cable is designed for situations where power handling matters more than pure signal loss. It strikes a balance between voltage capacity and power transfer, making it the standard for radio transmitters, Wi-Fi infrastructure, cellular equipment, and two-way radios. If you’re setting up a CB radio, a ham radio antenna, or commercial wireless gear, you need 50-ohm coax.
Solid Copper vs. Copper-Clad Steel
The center conductor inside a coax cable is either solid copper or copper-clad steel (a steel core with a thin copper coating). This distinction matters more than most people realize.
Copper-clad steel is cheaper and mechanically stronger, which makes it fine for basic cable TV connections where the cable only carries a signal. But it conducts electricity far less efficiently. An RG6 cable with a copper-clad steel conductor loses twice as much voltage over the same distance compared to solid copper RG6. That voltage loss becomes a real problem when the cable also needs to deliver power.
Satellite systems are the clearest example. The dish’s receiver (called an LNB) draws its power through the coax cable itself. If you use copper-clad steel, the voltage drop can prevent the LNB from functioning properly, especially on longer runs. This is why satellite installers specifically require solid copper coax. If you’re buying cable for a satellite dish or any system that sends power over the coax line, check the packaging for “solid copper” or “BC” (bare copper) rather than “CCS” (copper-clad steel).
Shielding Levels
Coax cables use layers of shielding around the center conductor to block outside electromagnetic interference from corrupting the signal. The amount of shielding varies, and it directly affects how clean your signal stays.
RG59 cables typically use a single layer of braided metal shielding, which handles low-frequency interference but leaves higher frequencies more exposed. RG6 cables generally combine a foil shield with a braided shield (called dual-shield construction), providing much better protection across a wider range of frequencies.
You can also find quad-shield RG6, which doubles up on the foil and braid layers. Quad-shield cable is worth considering if your cable runs pass near sources of strong interference: electrical panels, fluorescent lighting, motors, or areas with heavy radio frequency activity. For a straightforward home installation with no unusual interference sources, standard dual-shield RG6 performs well.
Frequency Ratings and Internet Speed
Modern broadband internet over coax relies on the DOCSIS standard. The current DOCSIS 3.1 specification uses up to 1.2 GHz of spectrum for data transmission, with the option to extend to 1.8 GHz. That means your coax cable needs to cleanly carry signals well above 1,000 MHz.
This is another area where cable type matters. At 50 MHz, RG6 loses only about 0.6 dB per 100 feet. At 1,000 MHz, that jumps to roughly 6.5 dB per 100 feet. Signal loss climbs with frequency, so a cable that works perfectly for basic TV channels (which sit in the lower frequency range) might cause problems for high-speed internet channels that use frequencies above 800 MHz. If you’re experiencing slow or unreliable internet on a coax connection, old or low-rated cabling is one of the first things to check.
RG6 rated for at least 1,000 MHz (sometimes labeled as “3 GHz” on retail packaging to provide headroom) is the minimum you should install for any new broadband or cable TV setup.
Connectors Are Not Universal
The connector on the end of a coax cable determines what equipment it can plug into, and different connector types serve different purposes.
- F-type connectors are the threaded connectors on the back of every cable modem, TV, and satellite receiver. They pair with RG6 and RG59 cables and are the standard for all residential video and internet coax.
- BNC connectors use a quick-lock bayonet twist mechanism for fast connection and disconnection. They’re common on professional video equipment, test instruments, and some security camera systems.
- SMA connectors are small, threaded connectors used for Wi-Fi antennas, handheld radios, and other wireless equipment. They look similar to F-type connectors but are about 2mm different in size, so they are not cross-compatible despite appearances.
Using an adapter to convert between connector types is possible in some cases, but each adapter introduces a small amount of signal loss. For the cleanest signal, use cable that’s already terminated with the correct connector for your equipment.
Fire Ratings for In-Wall Installation
If you’re running coax cable inside walls or through ceilings, fire safety ratings matter. Cables are tested not just for flame resistance but also for smoke generation, since toxic smoke in enclosed spaces is a major hazard during a fire.
Riser-rated cables (marked CL2R or CL3R) are approved for running vertically between floors and inside walls. Plenum-rated cables (marked CL2P or CL3P) are required in air-handling spaces like drop ceilings and ventilation ducts, where a burning cable could spread toxic fumes through a building’s air system. Plenum-rated cable uses a special jacket material that produces less smoke and resists flame spread. Building codes in most areas require the correct rating for each location, so check what your local code specifies before running cable through enclosed spaces.