What's the difference between RG6 and RG6 Quad Shielded?

[SolidSignal_Mike]

The main difference between these cables is that the RG6 Quad has four layers of shielding. Two of the layers are foil to block out high frequencies, and two are threaded to shield against low frequencies. RG6 just has two layers of shielding, one threaded, one foil. DirecTV and DISH Network recommend you use quad shielded RG6 for their high definition signal. We recommend quad shielded RG6 for all antenna installations. Regular RG6 or RG59 are much more susceptible to interference and can cause a range of problems. Ghosting caused from multi-path is one of the main problems for off-air reception, especially for off-air HD where tuners are more finicky. It is also recommended if you are running multiple cables next each other or if you are close to power lines. These cables have nearly the same dB loss per foot, so the clear advantage is that it eliminates many types interference.

-Mike