Recently I was talking to a guy that is cutting the cord and he wants to install an antenna and use the existing Coax in his home that has been patched together by a few different Cable and Dish Companies.
In his explanation there are four rooms in his home that he wants to hook to his TV Antenna. There are a Series of Splitters that have been installed along the lines to add additional rooms. His antenna signal is medium quality and he is wondering what he can keep because he doesn’t want to fish line through the walls.
Ok so lets look at this example because it is probably something that most of us will go through. Normally when an older home was wired for its first Cable TV service back in the 1980’s to late 1990’s the customer was only receiving TV Signal and a lower quality of cable RG-59 was installed. If you have this cable it is within the specs of TV Antenna signal range which is 0 to 900mhz. The splitters that were installed are also within range of antenna signals.
From the later 1990’s to today higher end services were installed in Cable TV Customer’s homes from Cable Modems to Pay Per View. These new services need an upgrade to the cable and splitters just to work. Interactive Cable TV and Cable Modems need a wider bandwidth and they need to be bidirectional. Today if you have Coax Installed in an existing home you should have RG6 and 1Ghz to 3Ghz Splitters. A 1Ghz bidirectional splitter and RG6 should be enough for all current services but if a higher end splitter is used that is also ok.
Wiring Layouts can vary by installer. Some installers don’t care about cutting into existing line and adding as many splitters as there are outlets in the home. The problem with having splitters is that they reduce the power of the signal passing through them. Also every time you cut into the line and add a connector or splitter you are introducing noise.
The Preferred Method of Wiring Homes for Cable or Antenna TV
Today the best method for running coax cable in your home is to run an individual line from each wall outlet directly to the demarcation point. The Demarcation Point can be where your Cable TV Service Box is or where the line from your Antenna Enters your Home.
You should use the best available Coax even if you never plan to install Cable or Dish because higher quality cable means less noise.
RG6 Cable comes in two types. Copper Plated Steel Cable is the most common however if you are using a Dish or if you are installing an Antenna with a Pre-Amp you should use Solid Copper Core Cable. Solid Copper allows electricity to flow back up the line and a preamp is a two part device that has a amp at the antenna and a power supply that is hooked to the coax inside your home. The Power Supply shoots the DC Voltage up the Coax Line to the PreAmp to power it. Also if you were to some day install a Dish a solid copper core allows the Dish Tuner to talk to the antenna and do whatever it does.
Most important though is that Copper is many many times better at conducting TV Signal than Steel. When you install an antenna you are capturing very weak electrical signals that run through the air from the TV Station’s Broadcast Antenna. The best Antenna would be made out of Silver and then Copper .. then aluminum and many steps down to steel. The difference between Copper and Steel could mean you lose a huge amount of signal even if the coax is using quality copper coated coax. But Steel is much less expensive and it is stronger.
For the consumer Copper Core Coax is really not that much more expensive if you are only buying 1000 feet or less but if you are a Cable TV installer who loads their Van with boxes of 1000 foot long spools every day the cost is important.
When wiring the average home you might see a $15 to $35 increase depending on the price of copper.. yes Copper prices do Vary and so will your cost.. You might find the same spool of wire in February is 30% less than in September because of demand. Not many people are installing coax in the middle of winter.
Distribution Amps vs Splitters
Once you get your cable in to each TV from the Demarcation Point the lengths of the wire may need a little boost.
Unlike Cable TV where the voltage of the signal is constant your Antenna Signal and Power through your home can vary by season if you have trees that block the signal in summer or snow on your roof in the winter. It can also vary by weather conditions if there are storms. And amazingly enough if you are in a weak signal area Sun Up and Sun Set will also have an effect on your signals not to mention all of the electrical disturbances that happen from neighbors and power grids and everything that happens when people wake up. This is why you can sometimes pull that distant TV station in really well late at night but not at all during the day.
If your signal is weak on Cable the Service Guy can pump up your Amp Settings outside your house at the box.
This is basically what a Distribution Amp does. It overcomes the loss in signal due to all your splitters, connectors and long lengths of coax.
These amps are inside your home and often have an adjustment setting for strength.
They are available from 1 to 8 ports and can cost from $20 and up depending on your need.
Don’t Mix your Cable Modem on these circuits. Always have a direct line from your Cable Modem to the Cable Company’s Box for the best results.
Splitters should be avoided at all costs but when you do need to split a cable you should only use a splitter with the fewest number of ports.
When you add a port on a Splitter or on a Distribution Amp each new port cuts the signal in half. So if a straight cable has 100% then a 2way split gives each split 50% and then each additional port would be a division of the straight 100% signal… .
When you get all the way out to a 8 way splitter you might as well just give up if you are on an antenna because so much of the signal is lost in just splitting to each TV .. this is why you use a distribution amp to make that 8way split and the Amp adds about 3db of extra power to each port to compensate for the 8 way split.
A Distribution Amp should not be considered a signal power amplifier .. it should be considered as a device that helps compensate for the loss of signal due to cutting wires, adding connectors and splitting them.. It just makes you come out about even.
Final Note
For Review the best method of installing cable is to install home run cables to each tv. Use a high quality Coax and for best results RG6 Solid Copper. If you do need to split your coax use a splitter with the exact number of ports you need.. ones with more ports will suck the life out of your signal because even if a cable is not attached the internals have already cut that power into more slices.
If you have great signal when you attach a TV directly to the line coming into the house but not at the TV Outlet.. then you might need to upgrade your wiring, reduce the number of splits in the line and install a Distribution Amp to overcome all the loss due to cable and splitters.
Best results can often mean just swapping out one or two small things or it can mean a total rewire of your home. If you are dealing with weak signal in a rural setting you must consider doing what is necessary to get every last bit of signal so new parts or cable can mean the difference of TV or no TV.