Coaxial Cable Types Reference: RG6, RG59, and RG11

The short answer

For most modern video and broadband signal work, RG6 is the default 75-ohm coaxial cable: it carries CATV, over-the-air antenna, satellite, and HD signals, and quad-shield RG6 is the common choice for satellite runs because of the higher shielding demand at Ku-band frequencies. RG59 is thinner, has a smaller center conductor, and shows higher loss per foot, so today it is mostly used for short analog CCTV baseband runs, SD-SDI, and low-frequency jumpers rather than high-frequency distribution. RG11 is the thickest of the three with the lowest attenuation per foot, so it is the choice for long trunk runs, typically past roughly 100 to 150 feet where RG6 loss becomes limiting. All three share a nominal 75-ohm characteristic impedance and are not interchangeable with 50-ohm cable.

The 75-ohm versus 50-ohm split is the first decision. RG6, RG59, and RG11 are 75-ohm cables optimized for video and broadband CATV, satellite, CCTV, and SDI. RG58 and RG8 are 50-ohm cables used for two-way RF: ham and CB radio, antenna feedlines, GPS, cellular, Wi-Fi, and test equipment. Mixing impedances causes reflections and signal loss, so the two families should not be substituted. Within the 75-ohm family, attenuation rises with both frequency and length, which is why spec sheets quote loss in dB per 100 feet at specific frequencies. The connector also follows the application: F-type threaded connectors dominate CATV and satellite, while BNC bayonet connectors are standard for CCTV and SDI. Choosing correctly means matching impedance, then attenuation budget, then connector to the equipment on each end.

How to choose between RG6, RG59, and RG11

Start with impedance, because it is not negotiable. RG6, RG59, and RG11 are all nominally 75-ohm cables. If the equipment is video or broadband CATV set-top boxes, satellite LNBs, TV tuners, analog or HD-over-coax CCTV cameras, or SDI gear then you are in the 75-ohm family and one of these three is correct. If instead the run is two-way RF such as a ham radio, CB, scanner antenna, cellular booster, or Wi-Fi antenna feedline, you need 50-ohm coax like RG58 or RG8 and none of the RG6/RG59/RG11 cables belong there. Impedance mismatch creates reflections measured as return loss or VSWR and wastes signal, so this choice comes first.

Once you are inside the 75-ohm family, the deciding factor is the attenuation budget over your run length at your highest operating frequency. RG59 has the smallest center conductor (commonly around 20-23 AWG) and the highest loss, so it suits short jumpers and analog CCTV. RG6 is the general-purpose middle cable (center conductor commonly ~18 AWG) and covers the majority of CATV, antenna, and satellite drops. RG11 has the largest center conductor (commonly ~14 AWG) and the lowest loss per foot, so it earns its extra cost and stiffness only on long trunk runs. Finish by matching the connector, F-type or BNC, to the ports on both ends.

• Impedance first: RG6, RG59, RG11 are 75-ohm (video/CATV/satellite/CCTV/SDI); RG58, RG8 are 50-ohm (two-way RF/antenna) and are not interchangeable.
• RG59: thinnest, highest loss per foot, short analog CCTV and baseband/SD-SDI runs and jumpers.
• RG6: standard general-purpose 75-ohm drop for CATV, over-the-air antenna, satellite, and HD; quad-shield version common for satellite.
• RG11: thickest, lowest loss per foot, long trunk runs typically beyond roughly 100-150 ft.
• Connector follows application: F-type for CATV and satellite, BNC for CCTV and SDI.
• Match all three: correct impedance, adequate attenuation margin at your top frequency, and the connector the equipment uses.

75-ohm vs 50-ohm: two different coax families

Characteristic impedance is a property of the cable geometry, the ratio of shield inner diameter to center conductor diameter and the dielectric constant, not something a connector changes. The two dominant standards are 75 ohm and 50 ohm. 75-ohm coax is optimized for low loss in video and broadband distribution where signals are largely receive-only or low-power, which is why cable television, satellite, terrestrial antenna, CCTV, and SDI all standardized on 75 ohms. RG6, RG59, and RG11 are the common 75-ohm building cables.

50-ohm coax is the standard for two-way radio-frequency systems because 50 ohms is a practical compromise between the impedance of lowest loss (around 77 ohms in air dielectric) and the impedance of highest power handling (around 30 ohms). RG58 (roughly 50-53 ohm) and RG8/RG8X are common 50-ohm cables used for ham and CB radio, antenna feedlines, cellular and Wi-Fi antennas, GPS, and lab test equipment. Connecting 75-ohm cable to a 50-ohm system, or vice versa, produces impedance mismatch: some energy reflects back toward the source, seen as elevated VSWR and return loss, degrading the signal. Use the family the equipment specifies.

The RG designation itself (Radio Guide) originated in the military MIL-C-17 / MIL-DTL-17 specification system. Modern building cable is more precisely described by MIL-DTL-17 or manufacturer part numbers and by series 6, 11, and 59, since generic RG numbers no longer guarantee exact construction. Treat RG6/RG59/RG11 as size-and-impedance families, then read the actual data sheet for shield type, dielectric, and rated frequency.

• 75-ohm family (RG6, RG59, RG11): CATV, satellite, over-the-air antenna, CCTV, SDI, broadband video.
• 50-ohm family (RG58, RG8, RG8X): ham/CB radio, antenna feedlines, cellular/Wi-Fi/GPS antennas, RF test gear.
• 50 ohms is a compromise between lowest-loss (~77 ohm in air) and highest-power-handling (~30 ohm) geometry.
• Mismatching impedance raises VSWR and return loss and wastes signal; do not substitute across families.
• RG = Radio Guide, from MIL-C-17/MIL-DTL-17; generic RG numbers are size classes, not exact specs.
• Always confirm shield count, dielectric, and rated frequency on the actual data sheet, not the RG number alone.

RG59, RG6, and RG11 side by side

RG59 uses a smaller center conductor (commonly 20-23 AWG copper or copper-clad steel) and a thinner overall diameter (around 0.242 inch typical). Its higher loss per foot at high frequency makes it a poor choice for satellite or long CATV runs, but it remains widely used for analog composite/baseband video in CCTV, for short SD-SDI patch runs, and as equipment jumpers. Its smaller bend radius and lower cost are advantages in tight, short runs.

RG6 is the workhorse. A center conductor near 18 AWG, an overall diameter around 0.270-0.275 inch, and a foam dielectric give it lower loss than RG59 across the CATV and satellite bands. Standard dual-shield RG6 handles most drops; quad-shield RG6 (two foil plus two braid layers) adds shielding effectiveness and is common on satellite and in high-interference environments. RG6 is rated to carry the full CATV and satellite IF range, into the low gigahertz, which is why it displaced RG59 for distribution.

RG11 has the largest center conductor (commonly 14 AWG) and the biggest overall diameter (around 0.405 inch), giving it the lowest attenuation per foot of the three. That makes it the trunk and long-run cable, used where RG6 loss would drop the signal below the receiver's threshold, often past roughly 100-150 feet. The tradeoffs are cost, stiffness, a larger bend radius, and connectors and tooling sized specifically for RG11. Many installs run RG11 for the long backbone and transition to RG6 for the final short drops.

• RG59: ~0.242 in OD, center conductor ~20-23 AWG, highest loss; analog CCTV/baseband, SD-SDI short runs, jumpers.
• RG6: ~0.270 in OD, center conductor ~18 AWG, foam dielectric; standard CATV/antenna/satellite/HD drop.
• Quad-shield RG6: two foil + two braid layers for higher shielding effectiveness; common on satellite and noisy sites.
• RG11: ~0.405 in OD, center conductor ~14 AWG, lowest loss per foot; long trunk runs beyond ~100-150 ft.
• Larger center conductor = lower resistance and lower attenuation, at the cost of size, stiffness, and price.
• Common hybrid: RG11 backbone to a distribution point, RG6 for short final drops.

Attenuation: why frequency and length both matter

Coaxial loss is quoted in decibels per 100 feet (or per 100 meters) at a stated frequency, and it rises with both frequency and distance. Loss climbs with frequency mainly because of the skin effect, current crowds into the outer surface of the center conductor as frequency increases, raising effective resistance, plus dielectric losses. This is why the same cable that looks fine at 50 MHz can be marginal at 1000 MHz or at satellite IF frequencies around 950-2150 MHz. Total loss is roughly the per-100-foot figure scaled by the run length, so doubling the run doubles the decibels lost.

In relative terms and at the same frequency, RG59 has the highest loss per 100 feet, RG6 sits in the middle, and RG11 has the lowest, following the center-conductor sizes. As an order-of-magnitude reference at CATV/satellite frequencies, RG6 loss runs on the order of a few dB per 100 ft at low VHF and rises to roughly the high-single-digits to low-teens dB per 100 ft near 1 GHz depending on construction; RG11 runs noticeably lower and RG59 noticeably higher at the same frequency. Always use the specific data sheet for design, since foam versus solid dielectric, copper versus copper-clad steel, and shield construction all shift the numbers.

For design, build an attenuation budget: take the source level, subtract cable loss at your highest operating frequency over the planned length, subtract splitter and connector losses, and confirm the result stays above the receiver's minimum. When RG6 cannot meet the budget over a long run, RG11 or an active amplifier is the usual remedy. Because decibels are logarithmic, every 3 dB is a halving of power, and 10 dB is a factor of ten, so small per-foot differences compound over long distances.

• Attenuation is quoted in dB/100 ft (or dB/100 m) at a specific frequency; both frequency and length increase it.
• Loss rises with frequency mainly from skin effect (current crowds the conductor surface) plus dielectric loss.
• At equal frequency: RG59 highest loss, RG6 mid, RG11 lowest, tracking center-conductor gauge.
• Satellite IF band is roughly 950-2150 MHz; loss there is much higher than at VHF, driving cable choice.
• 3 dB = half the power, 10 dB = one-tenth the power; small per-foot losses compound over long runs.
• Design by attenuation budget at the top frequency; use the real data sheet, not generic RG numbers.

Connectors, shielding, and applicable standards

Connector choice follows the application, not just the cable. F-type connectors are threaded 75-ohm connectors standard on CATV, broadband modems, and satellite equipment; they use the cable's own solid center conductor as the connector pin, which suits RG6 and RG11. BNC connectors are bayonet-mount and are the standard on analog CCTV, SDI video, and much test and broadcast equipment; 75-ohm BNC is used for video and SDI while 50-ohm BNC exists for RF, and the two are mechanically similar but electrically distinct. For serial digital video, SMPTE defines the SDI family, with SD-SDI at 270 Mbps, HD-SDI at 1.485 Gbps (SMPTE ST 292), and 3G-SDI at 2.97 Gbps (SMPTE ST 424); higher SDI rates shorten the usable coax distance and reward lower-loss cable.

Shielding matters as much as the conductor for interference rejection. Dual-shield RG6 pairs a foil with a braid; quad-shield adds a second foil and second braid for higher shielding effectiveness, useful near strong RF sources. Braid coverage percentage and foil quality determine how well the cable rejects ingress and prevents egress. For outdoor and buried runs, use cable rated for the environment (UV-resistant jacket, flooded/gel-filled for direct burial), and for in-building plenum spaces use the correct fire rating.

Installation is also governed by codes and standards. The National Electrical Code (NFPA 70) Article 820 covers community-antenna television and radio distribution coaxial cabling, including bonding and grounding of the shield, and NEC and NESC rules govern clearances. Grounding and bonding of coax entering a building is a safety requirement, commonly tied to the building's grounding electrode system, and ANSI/TIA-607 addresses telecommunications bonding and grounding practice. Structured-cabling layout follows the ANSI/TIA-568 family. Follow the equipment vendor's return-loss and impedance specs when terminating.

• F-type: threaded 75-ohm connector for CATV, cable modems, and satellite; uses the cable center conductor as the pin.
• BNC: bayonet connector standard for analog CCTV and SDI; 75-ohm (video) and 50-ohm (RF) versions differ electrically.
• SMPTE SDI rates: SD-SDI 270 Mbps, HD-SDI 1.485 Gbps (ST 292), 3G-SDI 2.97 Gbps (ST 424); higher rates shorten reach.
• Shielding: dual-shield (foil+braid) for standard drops, quad-shield (2 foil + 2 braid) for satellite and high-interference sites.
• NEC (NFPA 70) Article 820 governs CATV coax and shield bonding/grounding; ANSI/TIA-607 covers telecom bonding/grounding.
• Match jacket rating to environment: plenum-rated indoors where required, UV/flooded for outdoor or direct-burial runs.

Frequently asked questions