When going to the trouble of feeding coax through a building for a satellite TV installation – especially if you have spent time fishing cables through small holes and wall gaps – you will not want to ruin the whole installation for the want of these small plastic bushings.
Used correctly a feed thru bushing will help prevent damage to the insulation of the coax cable by preventing it from rubbing on any abrasive or sharp surfaces.
If you just leave your coax poking out of a hole then the chances of it chaffing against a plaster or brick wall are high. Even after a short period of time this can easily wear the insulation of standard RG6 coax cable.
Correctly installing coax with a feed thru bushing can also reduce the chances of RF interference entering the outer braid of the coax cable especially when feeding the cable through sheet metal casings where other electronic devices are present.
If the braid touches the casing it can easily induce annoying interference on your TV. This is sometimes extremely difficult to fault find post installation. A few of these plastic devices can prevent an awful lot of headaches down the line.
A feed thru bushing can be used in almost any surface, simply drill a hole to the recommended size and feed onto the end of the coax cable (after it has been fished through the wall). Do not push the bushing into the wall hole before feeding the cable through – this may seem common sense but its an easy mistake to make.
The feed through bushing is designed to grip the coax slightly so you will not want any additional friction preventing your cables from being fed through the hole in the wall.
The bushing is then simply pushed along the cable and should fit in the pre-drilled hole securely.