The short answer
Both cables are 75 ohm coax, the impedance used for television, satellite, CCTV and broadcast video. RG6 is the larger of the two: a thicker centre conductor and a thicker foamed dielectric give lower signal loss per metre, which is why it became the default drop cable for cable TV and satellite. RG59 is smaller and more flexible, with a thinner centre conductor and dielectric, so it loses more signal at high frequencies and over long runs. It survives mainly in short analogue CCTV runs, older video installations and equipment links where flexibility matters more than reach. Exact RG59 dimensions vary by maker and are taken from the datasheet of the construction quoted.
The "RG" label itself is an old military designation that no longer defines a precise construction. Two cables both printed RG6 can differ in conductor metal, braid coverage, jacket and weight, which is why the desk sources coax by construction sheet rather than by name.
Inside the reference RG6 construction
The reference RG6 on our LAN and coax cable page is built up from public datasheets. It has an 18 AWG centre conductor of about 1.02 mm, a physically foamed PE dielectric of about 4.57 mm, a bonded aluminium foil giving full foil coverage, a braid over the foil and a PVC or PE jacket. Overall diameter is about 6.6 to 6.95 mm, per datasheet. Recognised references for this kind of cable include ANSI/SCTE 74 and the IEC 61196 series, depending on the market.
Two variables matter most. The centre conductor is either copper-clad steel (CCS), usual for CATV, or bare copper (BC), usual for satellite with power feeding and for SDI video. The braid is either aluminium-magnesium wire at around 60% coverage, typical for CATV drop cable, or tinned copper wire at around 95% coverage, typical for broadcast types. Those two choices change weight from roughly 37 to 45 kg per kilometre for CCS with aluminium braid up to roughly 53 to 61 kg per kilometre for bare copper with a dense copper braid, per datasheet.
| Point | RG6 (reference) | RG59 |
|---|---|---|
| Impedance | 75 ohm | 75 ohm |
| Centre conductor | 18 AWG, about 1.02 mm, CCS or BC | Thinner; gauge and metal per datasheet |
| Dielectric | Foamed PE, about 4.57 mm | Smaller; foamed or solid PE per datasheet |
| Shield | Bonded foil plus Al-Mg or tinned copper braid | Often braid only or foil plus braid, per datasheet |
| Overall diameter | About 6.6-6.95 mm | Smaller; per datasheet |
| Signal loss | Lower per metre | Higher per metre, especially at high frequency |
| Typical uses | CATV and satellite drops, broadband, SDI (BC types) | Short CCTV runs, older video links, patch leads |
CCS or bare copper: the choice that trips buyers
At the radio frequencies used by cable TV and satellite, signal travels mostly near the surface of the centre conductor, so a copper skin over a steel core performs well and makes the cable stronger and cheaper. At DC and low frequencies the steel core matters. One public datasheet puts the DC resistance of an RG6 CCS centre conductor at about 100 ohm per kilometre, far higher than bare copper of the same size. That is why satellite installations that send power up the cable to an LNB, and CCTV systems that carry power or low-frequency signals, usually specify bare copper.
The mistake goes both ways. A buyer who needs BC for powered satellite runs receives CCS because it was cheaper; a buyer who only needs CATV drops pays for BC they did not need. The fix is simple: name the centre conductor metal on the spec sheet and check it on a cut sample. A magnet sticks to CCS and not to bare copper, and the cut face shows the steel core. The same logic of naming the metal applies to network cable, where category cable requires solid copper conductors; see CCA vs copper.
Shield, jacket and fire rating
More shielding gives better screening against interference and ingress, which matters in dense urban CATV networks and broadcast studios. Dual-shield RG6 (foil plus braid) is the common default; tri-shield and quad-shield versions add another foil and braid for noisy environments, at the cost of a stiffer cable and larger connectors. Connectors must match the shield build, so the desk confirms the connector type with the construction.
The jacket follows the installation. Indoor runs use PVC with the fire rating the market asks for; in the US, CATV cables carry CATV, CATVR or CATVP type ratings, chosen to satisfy the AHJ. Outdoor and direct-burial runs need a PE jacket and, where specified, a water-blocking compound under the jacket; an indoor PVC cable should not be buried. Rating hierarchies for data and communications cable are covered in NEC cable ratings.
Which one to buy
- CATV and broadband drops: RG6 with CCS conductor and Al-Mg braid, PVC indoors or PE outdoors.
- Satellite with LNB power: RG6 with bare copper conductor.
- SDI and broadcast video: RG6 type with bare copper and dense tinned copper braid; check the datasheet loss figures for the signal standard used.
- Short analogue CCTV runs and legacy equipment: RG59 where the existing connectors and short distances suit it; for new IP camera systems, network cable usually replaces coax, as described in PoE and conductor size.
Distributors stocking both types should keep them clearly separated by print and carton label. RG6 and RG59 look similar on the shelf, and an installer who grabs the wrong reel usually finds out only when the connectors do not fit or the signal level at the far end is too low. Distinct carton colours and a printed conductor metal on every reel label prevent most of those returns.
Packing, MOQ and documents
Coax is usually packed in 1000 ft (305 m) lengths on wooden reels or in reel-in-box cartons, the same carton format as LAN cable. Private label buyers can specify sheath print, reel labels and carton marks. Coaxial cable is commonly declared under HS 8544.20; your customs broker confirms the code from the construction on the spec sheet. MOQ and lead time are confirmed in writing for each order, and depend on conductor metal, braid and jacket because each combination runs as a separate set-up; the MOQ and lead time page explains the approach, and the quote form has fields for conductor, braid coverage and jacket so that offers can be compared like for like.