How to Split a Cable TV Line

by Joe Murray

    Cable TV wire comes in three types: RG-6 (heavy duty all weather above and underground), RG-11(medium duty indoor-outdoor) and RG-59 (light duty indoor). All three are coaxial; that is they have at least one layer of negative ground shielding and a center pole of copper-coated solid wire wrapped in plastic. When adding another TV receiver or high speed cable Internet, the single line entering your home or office needs to be split into two or more lines to accommodate the new devices. To do this you need a 75 ohm coaxial line splitter available in two, three, four or more outputs and additional cable. Signal loss can occur if output demand exceeds input signal strength (see Warnings).

    Step 1

    Determine, measure and cut the length(s) of wire you need to travel from the cable splitter to the device(s) requiring the cable signal input. Keep in mind that you want the cable to be unobtrusive and fixed to the ceiling, wall or floor. Add six to twelve inches at each end to avoid kinking in the coax.

    Step 2

    Affix the “F” connectors (the type that attaches to your cable box and 75 ohm TV inputs) to the ends of the coax wire lengths -- strip off one half-inch of outer coating, peel back the insulation and cut a quarter-inch of inner shielding to expose the copper coated solid center conductor. Slip the “F” connector over the end of the coax and push down until the copper coated solid center conductor pokes through the end of the center tube of the “F” connector.

    Step 3

    Crimp the “F” connector to the end of the coax; use the crimping tool on the wire ring at the coax cable end of the connector. Check the firmness of your connection by attempting to turn the “F” connector gently. If it turns at all, remove the connector and start over with a new connector. Test the cables with a continuity checker or circuit checker by touching each end to the probes. Do this for both the outer ground and the inner copper coated center wire. If the checker does not light up to show a closed circuit for both, remove the connectors from each end and start over with new connectors.

    Step 4

    Connect the main coax line to the input of the splitter by screwing it on the tip and securing it with the pliers. Connect the other coax lines you have made to the output of the splitter. These will generally be labeled with “-3dB” or similar, signifying the amount of line loss created by splitting the coax signal. Connect the other ends to the devices requiring coax cable input. Tack down the coax using cable tacks.

    Tips

    • If you are only running two wires a short distance (one to three feet), purchase pre-cut RG-59 cables. Making your own wire lengths is generally less expensive than buying pre-made up wires if more connections and longer distances are involved. For lengths over three feet and any outside cables use RG-11.

    Warnings

    • Ask your cable company what the signal strength coming into your home or office is in dBs (signal strength measured in decibels) and how many splits are allowable before a line amplifier is required. Do not attempt to split the signal if it is less than 3dBs.

    Required Items

    • Coaxial TV cable
    • Cable splitters(s)
    • “F” connectors
    • Cable crimper/cutter
    • Cable tacks
    • Pliers
    • Continuity or circuit checker

    About the Author

    Joe Murray San Francisco, CA, US Joe Murray began writing professionally in 1980. As a technical writer, he authored numerous white papers, journals and articles for publications and websites for Hewlett Packard and Intel. Since retiring, Murray has written several home-exchange travel articles for KnowYourTrade.com and CHECtravel, among other outlets. He holds a Bachelor of Arts in philosophy from Santa Clara University. Murray has made more than 50 vacation home exchanges worldwide.

    Photo Credits

    • Comstock Images/Comstock/Getty Images