Many are starting to feel that using RG-6 60% shield is "shorting the customer" as Quad Shield is all that is recognized by Structured Wiring manufacuters like On-Q, Leviton, Channel Plus...
Arrrf! Those idiots will specify anything without a real reason.
RG-6 with a bonded foil under a 60% braid is fine for almost all installations. Only time you may want to use something with more shielding (and that is not necessarily "quad shield") is if you have RF ingress problems- and you would probably have to be next to a high power transmitter of the right frequency to have them.
Keep in mind that all cables of a type will exhibit the same attenuation. This means that, for instance, all RG-6 size cables with a foam dielectric will all have the same attenuation and regardless of the shielding. So using a "quad shield" cable will only cost you more money and make installation more difficult because it is larger and less flexible.
Notice also that I said RG-* size cables. That's because the actual RG cables have a solid dielectric, solid copper center conductor and a copper braid shield. Though these are still available (preferred for video applications) the cables we generally use are not RG design at all and only maintain the original sizes- 59, 6 and 11.
... On a CCTV project, I specify RG59 for circuitry within an equipment rack or group of racks for ease of interconnection. Coax going out of the room (or into the room) is RG6. RG6 is better for long runs.
Unless your runs are VERY long RG-59 size cable is fine. This is because video will never exceed 6Mhz and the attenuation in that range is low even for RG-59.
CATV which can go to 750 or 1000Mhz and satellite which goes to 1450Mhz requires a lower loss cable to be able to run it any distance.
-Hal
[This message has been edited by hbiss (edited 10-12-2004).]
