How To Use Your Existing Cable or Dish Coax For Antenna Installs

If you are contemplating cutting the cord and going with an antenna and a broadband subscription for Netflix, Hulu and whatever else then one of the hardest parts is rewiring your home. In many cases homes that already have a Dish or Cable TV subscription have existing coax to each room. The quality of the install including the layout, coax type and equipment such as splitters will differ based on the age of the home and the service you have.

In this how to we will cover the reuse of existing coax cable to provide an easy method for installing your antenna while preserving a connection for your cable modem. If you are using DSL or FIOS then your data connection may be separate and in this case your install might be easier.

The first thing you should understand is that antenna signals are on the lower end of the mhz scale. They run from about 54mhz for channel 2 up to UHF frequencies that can get in to the 800mhz range. Cable and Dish installs normally require the lower frequencies that antenna covers up to and beyond the highest TV signal spectrum. You can see this when you are buying splitters. Antenna Splitters are 1ghz or below and cable and dish splitters are rated up to 2000mhz. This means what you have should be more than capable to cover your antenna that has lower requirements.

This was a thing back in the 1980’s when people had just wired their homes for antenna with coax and wanted to install a dish or cable. In the beginning cable only went to 1ghz like antennas and things worked fine but once cable modems and dvrs with on demand were introduced a lot of homes had to rewire and replace all their splitters.

Although most of your wiring and splitters should work you could still run into problems and we will cover that.

Now that you have decided that you want to move on to an antenna for local broadcasts you should visit www.tvfool.com and run your signal report. You want to use your coordinates if you can which you can find by finding your home on Google Maps and then clicking on it. A small popup will appear and give you your coordinates. Place them in the box on tvfool and then make sure you are adding the height of the antenna. For single family homes with antennas in their attics or on their roofs this is important because 10 feet will make a difference and you might even need to install a roof antenna with a pole extension for best results. Some people may even need a free standing antenna tower that can be 50 feet tall but you will have to check on your local regulations on how high your tower could be.

Now that you have your signal you need to know what the nmDb ratings are for the stations you want. If all of them are over 35nmDb then you are in luck and you can go with an attic or roof antenna and expect to get great results without an amplifier. If you have lower signals or signals from more than one direction you will need an amplifier to boost your signals and you will either need a rotor to turn the antenna or you will need two antennas to pickup more than one direction. Eight Bay antennas are an option for people with signals in two directions but they will not pickup VHF so look at your chart and see if any of the stations are REAL CHANNEL 13 or below. If they are you will need a VHF antenna to pick them up. When buying your antenna you may see some UHF antennas that say they can pickup VHF but normally that is only for stations with very high signals of 50nmdb and higher and stations over real channel 11 to 13. They also do not do well in distances over 25 miles.

So, you have your TVFool Report and your Antenna or Antennas selected. Now you need to wire them to all of the rooms where you want television.

 

Wiring Your Antenna With Existing Coax Cable

The first thing you want to do is inspect your wiring and devices. If you have Cable TV go outside to the box on the side of your house and see if you have more than one wire running from your home into the cable box. If you do you probably have individual runs to each room. If you do not then your wiring is split inside your home.

Since you probably also get broadband off a cable modem you want to make sure that you have a single wire running from the cable modem to the cable tv box outside your home so that it gets good signal. An easy way to find out which wire is running to the cable modem is to attach a tv and open your window. When you hear the tv go off then you know you have the right one. Keep that wire attached to the cable companies splitter.

The rest of the wires in your home and all the outlets should run off of the remaining wires. The easiest way to do this is buy your own box that is similar to the cable companies box and hang it near the cable box and transfer all your home wires into it except the cable modem wire. Now you can install your antenna on your roof or in your attic and only need to run 1 wire down to your new box.

Some homes might actually run 1 wire from the cable box outside into your basement and then do the split there. You will have to track that down and find out.

The hard part. If your home was wired with many splitters inside your basement or attic to attach one room to another room instead of running single wires from each room back to a primary splitter then you may need to rewire your house.

Every time you add a 2 way splitter you cut the power of the antenna signal by about 3db.. each drop of 3 db means a 50% reduction in power from your antenna to your television. Having the fewest splitters and connections or cuts in the wire preserves the signal from your antenna.

One good thing is you can often use your existing wire to tape a new wire to and pull it through the walls. Running wire is not that difficult but it does take time and is often best done with someone to help. You can do all the work yourself but expect to take more time as you run from the basement or attic into rooms to pull the wires through.

One option if you have existing wiring that goes through a series of splitters and you find you have good signal on some outlets and poor signals on outlets at the end of a few splitters is to just run that one wire for that room back to a common point.

Another option is to add a distribution amplifier that is use to take the single wire feed off your antenna and then attach all of your home wall wires. An amplifier can come in 2 to 8 ports and the 8 port models are great if each room is individually wired but the 2 port can also bump up signal high enough to overcome all your splitters and bad wiring.

Update all your coax wire connectors with compressing fittings

Another thing that is a real must is to install good connectors on your wires. If a cable installer did the work they probably used compression fittings. You can buy them and the tool online and they do a much better job than the crimp connectors or screw on type.

Concerns for Dish Owners

Lets quickly cover some of the unique problems dish owners may have. The first thing is will you be using your dish pole to mount your antenna. If so then simply detach the dish and connect the wire to your antenna. Then make sure your antenna is properly grounded with a ground wire that is run down the side of your home into the ground on a grounding rod.

Much easier is to pull that wire back into the attic and then mount your antenna inside your attic. This is a strong possibility for many people but others will need a roof mount or sidewall mount antenna that is outside your home. Outside mounting will improve your signals considerably but you must run an independent ground wire to the antenna or you could blow out your televisions or cause a fire if lightning strikes. And it doesn’t have to be a direct strike it can be many yards from your antenna.

The next thing is Dishs are powered so you will have to decide if you are going to keep the dish and add the antenna or remove the dish. If your provider doesn’t want the dish back when you end your service then you can keep it in place. If you are continuing your dish service for premium channels then you will need a special splitter that is called a power passing splitter.

One wire off the splitter will go back into your home (or you can make the connection in the attic to keep it dry) and one wire off the two opposite side ports will go to the dish and the other to the antenna. The dish side will require the power passing port.

This can get more complex if your antenna requires a preamplifier at the antenna. In that case you will have to add a small wire out of the port to the antenna and then install your power inserter for the preamp. Then you can install the preamp and then run a wire to the antenna.

So it will be…

Home -< split to antenna and power passing side for the dish .. then on the antenna side add the power inserter for the preamp if an amplifier is needed and then the wire to the antenna.

If you draw these wires on a diagram before you begin you will be much happier when you are working.

 

Final Note

Ok so laying out your wiring is important especially if you need to use a preamplifier and a distribution amp.

Your best situation is when each room in the home has its own wire run to the dish or to the cable box on the outside of the house.

You can use distribution amplifiers to boost signal in homes with many splitters and poor wiring.

You can also choose to remove your dish or keep it installed. Antenna signals will not cause problems for dish installs normally because dish is much higher on the frequency scale than antenna signal.

Finally for antenna users and Cable TV subscribers you can not mix those signals.

If you have an antenna you can not connect it to a live coax off your cable tv box you must remove all the wires from the box and use your own splitter or distribution amp to improve signals.

A single wire from your cable modem should be run to the cable box outside your home.

So Cable and Antenna wont mix.. Dish and Antenna can mix but you will need a special splitter. Often you can ask your dish installer for advice or maybe they will install the antenna for you. I know they will install one for you at a cost but thats not something you want.