said by Bluetrue:
...instead of using quad shield, they want to use dual coax with a "messenger" wire. They want to run the dual shield from the dish to close to the electrical service and install an 18 inch ground wire from the ground block to the service ground. So far so good (although the total cable length will be about 175 feet). However, to ground the dish and radio, they want to use the messenger wire to connect from the dish to the ground block.
I gotta say that your description has me completely baffled. If the dish is close enough to your service entrance to use an 18" ground wire, why on earth bother with an otherwise useless "messenger ground"? And 175 feet of it as well !! I don't get it.
Messenger wire is a functional component of aerial cable
, meant to support the weight of the attached cable. Because if/when the center conductor is permitted to stretch, its resistance value increases as the gauge (diameter) decreases. Result - signal attenuation. If/when the shielding is permitted to stretch, it will simply break and separate. Result - loss of signal ground path. The sole purpose for messenger wire is to prevent stretching of suspended cable. Besides that, messenger wire is typically 17ga steel, not even copper clad. Hughes requires ground wires to be minimum 10AWG copper or 6 AWG aluminum.
Aerial cable is also UV-resistant, since it's assumed to be typically installed in direct sunlight. But aerial cable is NOT flooded
- which means it does not have the waterproofing necessary for direct bury applications. I think you'd grow old trying to find flooded (direct bury) cable with a messenger wire, that is otherwise suitable for use with a HughesNet system.
Even though FSB 050518.1C suggests it's an acceptable installation procedure, I strongly disagree with Hughes about running the ODU ground wire through the cable block. The wire between the ODU and common ground represents the electrical ground (primary DC return path and lightning prevention). The wire between the cable block and common ground represents the signal ground (DC zero reference and alternate DC return path). The two should NOT intersect, except when both ultimately arrive at the common ground. And it's best when the distance between the cable block and the modem is LONGER than the distance between the cable block and the common ground point.
Alden - relative to your comments, I do
endorse the general use of QuadShield, but not for the reason you imply. There is nothing to support an assumption that QS is universally better on longer runs. QS is engineered primarily as a low noise cable
, nothing else. The key to long cable runs is to actual READ the specs on the cable before you even buy it. If it has an acceptable loss figure, whether or not it's of QS construction - is irrelevant. Example; Hughes FSB 060316.1a approves CommScope 5729 (dual shield) for 1 watt runs up to 276 feet. They approve Perfect10 Quad for 1 watt runs up to 277 feet. So you can see in this case, there's no "length" advantage to using that particular quad cable.
As a side note, I also strongly disagree with Hughes FSB 060316.1a where it implies Quad shielding provides a viable electrical ground path. As above, shielding should be relied upon for signal ground only. Solid copper or aluminum should be the default electrical ground, all the way from the ODU to common.
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