What's the Difference Between RG6 and RG6Q Cables?

Chances are you have a coaxial (sometimes called RG), cable running into one or more of your gadgets and devices. These cables are typically used for television and high speed internet and there is a single silver pin at at least one end, encased in a screw-on bracket.

Although markings on the jacket distinguish the type of coaxial cable you are using, the wires are largely identical with only minor weight and size fluctuations. But the model does make a difference. Let's look at some of the differences between various coaxial cables.

Most RG cables follow a familiar structure. There is an insulated inner conductor (usually copper or aluminium) shielded by a copper foil and encased in black or white plastic. The conductor carries the signal while the insulation and shield maintain the conductor's integrity. Insulation comes in various thicknesses, which increases the diameter of the cable and accordingly influences size and weight, although the differences are usually microscopic.

One of the things that various coaxial cables have in common is the classification of their insulation. Since these cables often run outdoors, the effects of the environment--rain, snow, and so on--are of paramount consideration. The average coaxial cable has a classification of MIL-C-17, which is the standard grade required to protect the inner workings from common environmental damage. Other coaxial cables--those used in more extreme locales--boast the heavy duty classification of M17/74, which is military grade. M17/74 insulation degrades at a much slower rate than its MIL-C-17 equivalent, and protects the signal more completely. Coaxial cables can also be run underground.

RG59 cables used to be industry standard for in-home connections, but RG6 models are gradually taking over. Note that the RG6 is not the same as the RG60, which is a rare kind of coaxial cable and difficult to find (you probably don't need to worry too much about it).

The name of the game here is conductor size, with the RG6 boasting increased diameter and thus increased conductivity at frequencies of 50 megahertz or higher (RG6 cables can handle up to 1.5 gigahertz). More signal equals superior picture for your home entertainment system, and more speed for your internet connection. At this stage, you really want to be running the RG6 or RG6Q, as the quality of high definition has improved over time and the frequency of the broadcast has also increased. Standard high-definition runs at a 37 megahertz signal, so RG59s can handle it easily, but the RG6 is generally better with less signal loss.

There is a caveat, however. Bigger is not always better, as certain sizes are intended for specific voltages and broadcast frequencies. A conductor can be too large for the information flowing through it, and this can create various undesirable effects such as "ghosting"--an image that stutters or doubles up on itself. For this reason, each RG cable is intended for a specific use. The RG6s, for example, run at too high a frequency for things such as video projectors or composite connections. Sticking in the most powerful cable to your television will not necessarily improve the picture.

With RG6 cables comprising most home-entertainment set ups, knowing the difference between the two types is paramount. The main thing that distinguishes the RG6 and the RG6Q is the kind of inner shielding used to insulate the delicate wires. The superior "quad" shielding of the RG6Q minimizes outside disturbance and thus maintains a higher integrity of signal. The difference in diameter also increases the amount of voltage than can be passed through the conductor, with RG6Q cables allowing more room for the electricity to do its magic. As technology improves and more and more competing signals reach the airwaves this increased insulation will become increasingly important--especially as 4K takes hold of the market.

RG11 cables function in the same way as RG6s, but have better insulation and a larger diameter. They are one step up from their RG6 sisters.

The RG8 and RG213 variety of coaxial cable are used when an especially high voltage--higher than the RG6 devices--is required to carry the signal from antenna to device--an example being a two-way radio tower. They are often used to broadcast VHF and UHF signals, although they can also be used for picture or data.

In these cases, a high voltage increases the chance of signal loss, so the strength and width of the cable must be amended accordingly. The RG8 models max out at 4,000 volts between conductor and insulation, while the RG213 can go to 5000 volts. Accordingly, the RG213 cables are wider in diameter, slightly heavier (around 10.6 lbs vs. 10.5 lbs) and more fragile in higher temperatures. RG213 cables, however, offer an improvement in insulation quality, so aside from the heat, they are more sturdy and degrade less quickly.

As mentioned before, the RG6 varieties of coaxial cable are the ones you will most commonly encounter with your home appliances, although for the most powerful systems, RG11 works best. The RG6Q is best for consumer grade telecommunications, and unless you have a radio tower in your backyard you won't need to worry about the other kinds. RG 59 cables can handle older television frequencies and are fine for a security camera network.

To summarize, the considerations you should take into account when choosing an RG cable are:

• The location in which you'll be running the cable and grade of insulation.
  
• The diameter of the inner conductor, the space available for the voltage and signal, and
  
• The amount of electricity required to power your desired appliance.