• Differences between RG-6 and RG-59 cables dictate when and where they're used.Coaxial cable image by lefebvre_jonathan from Fotolia.com
  
  RG-6 and RG-59 are the predominant coaxial cable types in residential use. Coaxial cable is defined by construction. Any signal carrying cable that has the conductor and ground on the same axis is a coaxial cable. In most instances, RG-6 and RG-59 are more than capable of carrying high bandwidth, with the edge over longer distances going to RG-6. The physical differences between the two cables dictates their applications, and knowing them helps you understand why one type is preferable over another depending on the installation.
  
  

Inner Conductors

• RG-6 cabling uses a larger center conductor than RG-59, making attenuation over long distances less of a factor. For this reason, RG-6 is preferred in high-bandwidth scenarios, such as digital cable service feeds that encompass broadband Internet and high definition, and satellite feeds. The larger center conductor of RG-6 means that it has the ability to maintain bandwidths into the gigahertz range, twice that of RG-59.
  
  

Shielding

• RG-59 has a single copper shield, while RG-6 has a foil and braided shield, effectively negating most interfering radio frequency interference. Often times, RG-6 uses four layers of alternating shielding, known as "quad shield." RG-6 is the type of cabling most often seen in delicate satellite installations. The multiple layers block electromagnetic interference from "scrambling" an undecoded digital signal from a cable provider's hub or satellite dish.
  
  

Strengths of RG-59

• RG-59, although possessing less inner shielding, is actually better suited for applications where a video signal is being sent from a video source to a display. That's because the copper shielding on RG-59 rejects interference of 50 MHz and below, while foil shields don't. The shielding effect is one reason why consumer video cabling (such as component video cabling) tends to be smaller than RG-6. Ironically, extra shielding and thickness can be detrimental. RG-59 is not only ideal from a physics and electrical perspective for making video cables, but it potentially reduces the overall cost of projects. Use RG-6 to bring the signal in from the outside, and use RG-59 to carry it from component to display.