RG6 vs RG59: Which Coax to Use, and When It Matters

Both cables are 75 ohm coaxial. Both take the same F connectors, both carry a picture, and both are sold in the same aisle. The difference shows up when the run gets long, the frequency gets high, or the cable sits in a bundle with others.

So this is a length-and-signal question rather than a quality question, and the answer is usually decided before you open the catalog.

Quick answer

	RG59	RG6
Impedance	75 ohm	75 ohm
Center conductor	Thinner, typically 20–22 AWG	Thicker, typically 18 AWG
Loss at a given frequency	Higher	Lower
Flexibility	More flexible, easier to route in tight spaces	Stiffer, larger bend radius
Typical role	Short analog runs, patch leads, legacy installations	Longer runs, higher frequencies, satellite and HD analog
Shield options	Usually single braid, or foil plus braid	Commonly quad shield

The names are dimensions, not performance ratings

RG6 and RG59 come from an old military designation system, and the numbers identify a cable’s physical construction rather than a grade. That is why a cheap RG6 and an expensive RG6 can differ substantially, and why "RG6" alone does not tell you whether a cable is suitable.

What actually decides performance is a short list: the center conductor’s size and material, the dielectric, and how completely the shield covers the dielectric.

Where the loss comes from

Signal loss in coax rises with frequency, for both cables. It also falls as the center conductor gets thicker and as the dielectric gets larger in diameter, because both changes reduce the resistance and the field concentration that cause the loss.

RG6 is built larger on both counts. Its center conductor is thicker and its dielectric is bigger, which is the whole reason it loses less signal per unit of length at the same frequency.

This is why the practical guidance is directional rather than absolute:

Run length	Reasonable choice
Under about 15 m, analog video	Either, and RG59 is easier to work with
15 to 45 m, analog video or CCTV	RG6
Satellite, or any run carrying a high-frequency signal	RG6, and check the manufacturer’s attenuation table against the frequency in use
Short patch leads inside a rack	RG59 is often chosen for flexibility

The specific loss figure matters and it is frequency-dependent, so the number to compare is the one on the datasheet at the frequency your system actually uses — not a single figure quoted for the cable.

The center conductor question

Both cables are sold with different center conductor materials, and this is the detail most likely to catch you out.

Solid copper gives the lowest resistance and the best loss figure.

Copper-clad steel uses a steel core with a copper skin. It is stronger, which matters where the cable is pulled or where a messenger wire is attached, and it is very widely used in RG6 for exactly that reason. Its resistance is higher than solid copper, so loss is slightly worse — but for many runs it is an acceptable trade for the mechanical strength.

Copper-clad aluminum appears in inexpensive cable. It is the weakest of the three electrically, and it is worth knowing that the site’s verification guide for copper-clad conductors covers how to check what a cable actually contains, since the marking is not always informative.

For a run where loss is already marginal, the conductor material can be the difference between passing and not. For a short run, it is not.

Shielding, and why RG6 is the one with more of it

The shield’s job is to stop interference reaching the center conductor and to stop the cable radiating. Covering the dielectric more completely does that better.

RG59 is commonly offered with a single braid or a foil-plus-braid combination. RG6 is where quad shield became standard practice: two foil layers and two braid layers, which covers the dielectric far more completely and keeps the layers in contact.

Where the cable runs beside mains wiring, inside a rack with power supplies, or through a building with a lot of electrical noise, that difference is worth having. What quad shield actually means is covered separately, because the term is used loosely in listings.

Connectors and the size problem

Both cables use F connectors, and F connectors are sized to the cable’s dielectric diameter. A connector made for RG6 will not grip RG59 properly, and the reverse is worse.

The practical consequence is that RG59 and RG6 need different connector stock, and a mixed installation needs both. Choosing and fitting coax connectors covers the types and the termination methods.

Scenarios

A four-camera analog CCTV installation with 20-meter runs. RG6, compression F connectors, and the camera power run separate or on a siamese construction. The CCTV coax guide works through the specifics.

A short patch between a wall plate and a television. RG59 is entirely adequate and easier to bend.

A satellite dish run of 30 meters. RG6, and the loss figure at the LNB’s frequency range is the number to check.

An older building being extended. The existing cable is RG59. Extending with RG6 from a splitter is normal and works, provided the splitter and connectors suit the cable in each leg.

A commercial AV installation with runs through a ceiling void. RG6 with the jacket rating the space requires, plus a shield adequate for the electrical environment. The commercial AV selection guide covers the installation side.

FAQ

Is RG6 better than RG59? RG6 has lower loss and usually better shielding. For short runs the difference does not show, and RG59 is easier to handle.

Can I use RG6 and RG59 in the same system? Yes. Use the connector that matches each cable and keep in mind that the run is limited by its worst section.

Which is better for CCTV? RG6 for anything beyond a short run. RG59 works for legacy analog systems over short distances.

Does RG6 carry more channels? The cable does not limit channel count directly. It limits how much signal survives the run, and how much of the frequency band it can carry before loss makes the signal unusable.

Do RG6 and RG59 use the same connectors? The connector type is the same, but connectors are sized to the cable’s dielectric, so the parts differ.

Does the center conductor material matter? Yes. Copper-clad steel is stronger and slightly lossier than solid copper; copper-clad aluminum is worse again.