Actually the Belden 1694a cable is RG6 and the cable has better shielding then the Canare cables mentioned here.
Its SMPTE ratings for HDTV, Component and Composite are higher as well. It meets the specs over longer lengths than the Canare cables. The Belden 1694a cable is used by most Broadcast and production facilities including Lucas THX. These specs are all available on the Belden web site so you can compare them yourself.
Rememebr if you are going the DIY route make sure you invest in high quality connectors or you may as well use cheap and inferior cable.