Introduction

Often overlooked, the coax cable within a TV system is just as important as each of the other components. Not all coax cable is the same. This page will explain the different types of coax cable and explain which coax cable is the most preferred to use within your TV system. There are three different types of coax cable often used. They are RG-6, RG-11, and RG-59. The major differences include how much shielding the cable contains, size of the center conductor, and the material type of the center conductor. The best coax cable to use, within an over-the-air TV system, is a RG-6 Quad Sheild with a solid copper center conductor for cable lengths less than 100 feet. For coax cable lengths longer than 100 feet, the RG-11 Quad Shield with solid copper center conductor is the best coax to use.

RG-59 Coax Cable

RG-59 coax cable is the smallest, thinnest, and the cheapest cable when compared to RG-6 and RG-11. The most common RG-59 cable contains only one, thin layer of shielding. The most common RG-59 cable does not contain a solid copper center conductor. Instead, it contains a copper-clad center conductor. The copper-clad conductor is NOT solid copper. Copper-clad is a much cheaper and less effective material than solid copper. A thin layer of copper is placed around the outer edge of the cheaper material. This is one reason why RG-59 causes a significant amount of signal loss within a TV system. Secondly, a preamplifer recieves is power through the coax cable. The preamplifier is located near the antenna and its power adapter is located at the opposite end of the coax cable, near the TV tuner. The preamplifer power adapter send power through the coax cable to the preamplifer. An RG-59 cable cannot send power very well. As a result, the preamplifer may loose power and the TV signal will become degraded. A good coax cable will contain a solid copper center conductor. Secondly, RG-59 normally contains only one small layer of shielding. This is not enough shielding to keep away interference from the sun, weather, and near by electronic devices. With all of the signal loss and the high susceptibility of adding interference, the RG-59 coax cable is NOT recommended for use within an over-the-air TV system.

RG-6 Coax Cable

RG-6 coax cable normally includes a solid copper center conductor. The RG-6 coax cable normally includes either a dual layer shielding or a quad layer shielding. If you are running a coax cable with a length less than 100 feet, the RG-6 quad-shield is the preferred cable that should be used within your TV system.

RG-11 Coax Cable

RG-11 coax cable is the most expensive among the three cable types. The RG-11 coax cable normally includes a solid copper center conductor. The RG-11 coax cable normally includes either triple layer shielding or quad layer shielding. If you are running a coax cable with a length more than 100 feet, the RG-11 quad-shield is the preferred cable that should be used within your TV system.

Comparison of Coax Cable Specifications

Coax Cable Specifications
Characteristic	RG6	RG11	RG59
Center Conductor Size:	18 AWG	14 AWG	22 AWG
Most Common Center Conductor Material:	Solid Copper	Solid Copper	Copper Clad
Maximum Distance:	100 ft.	400 ft.	----
Diameter:	0.275 in.	0.405 in.	0.242 in.
Shielding:	Two-Layer & Quad-Layer	Three-Layer & Quad-Layer	One Thin Layer
* Signal Loss:	6 dB/100 ft.	2.5 dB/100 ft.	10.9 dB/100 ft.
Impedance:	75 ohms	75 ohms	75 ohms
Flexibility:	More Flexible	Less Flexible	Very Flexible
Bandwidth:	1 Ghz	3 Ghz	----

* - Calculated at 539 Mhz. This is directly in the middle of the UHF band (470 Mhz.-608 Mhz.)

Conclusions and Recommendations

1.) Use RG-6 coax cable for lengths up to 100 feet. Quad-shield is preferred. Dual-shield is acceptable. Make sure the center conductor is solid copper.
2.) Use RG-11 quad-shield for coax cable lengths greater than 100 feet. Quad-shield is preferred. Make sure the center conductor is solid copper.
3.) Avoid using RG-59 coax cable.
4.) Avoid any TV antenna that has a coax cable permanently attached to it.