TV Antenna to the TV Part 1 – What's In-Between is Important
You bought that brand new antenna so you could cut the cord and get full quality free TV instead of paying for those compressed, less than optimal pictures from your satellite or cable supplier! That's great, but what else did you get to make sure those high-quality HD signals from the antenna get to your TV set? That can be just as important as buying the right antenna! The quality of those components, and the workmanship to install them can make all the difference.
So, what do you need? For most installations, good quality coaxial cable, good quality compression "F" connectors, and a good quality splitter if you need to connect more than one TV set, is all you will need to get those high quality signals all the way to the TV set. Poor quality components and poor installation practices will all degrade your signals before they get to the TV set. In this article, we'll give you a high-level overview for these components. In later articles, we'll discuss each component and good installation practices in more detail.
One issue to keep in mind is that cable and splitters will cause signal loss, so cable lengths need to be kept short and direct. If long cable runs are needed, an antenna preamplifier or a distribution amplifier may be required. Amplifiers will be the subject of another article (also, amplifier information is available on the Channel Master website).
Coaxial cable comes in several sizes. The recommended cable for OTA installations is RG6. This is a 75 ohm coaxial cable a little over ¼" inch diameter (0.275 inch) A high quality RG6 cable will have good protection against unwanted interference leaking into the cable. Usually, what is called "tri-shield" cable will do the job. This cable has a layer of tape, a layer of braid, and another layer of tape between the jacket and the insulation over the center conductor. Black cable is recommended for outdoor use since it is UV stabilized and the jacket won't get brittle and break over time. It's important that the cable doesn't get flattened or bent too tightly when installing it. That will degrade its performance and cause excessive signal loss.
"F" Connectors are critical as well. It is important that they are installed correctly onto the cable and are tightened properly onto ports (connector installation instructions are on the Channel Master website). Compression connectors are recommended since they do a better job of sealing the connector/cable interface from water. If water gets into the cable or interface between the connector and the port, it will degrade the signal quality and strength. Channel Master "F" connectors include a lock washer to keep them tight, and two O-rings to completely water seal the entire connector and port to which it is attached.
If multiple TV sets need to be connected to the antenna, you will need to use a splitter. These are available with 2, 3, 4 and 8 output ports. You should use a splitter with enough ports for the TV sets you have because the more ports on the splitter, the higher the signal loss going through it. Use a 2-way splitter for two TV sets, not an 8-way splitter. Since splitters have a major impact on the performance of your OTA installation, high quality splitters should be used to ensure the best signals to your TV sets. It is always best to locate the splitter in a central location and run individual cables to each TV set from that central location. You can place splitters in multiple locations, but since each splitter causes more signal loss, installing them along a single cable run is not recommended. It is much easier to control the signal levels by centralizing the splitter and using "home runs" to each TV set.
As I mentioned above, cable and splitters will cause signal loss, and to get the best signal to each TV set, those losses must be controlled.
|Signal Loss at Channel 35 (600 MHz)|
|RG6 Coaxial Cable||5.1 dB per 100 feet of cable|
|2-way splitter||3.9 dB per port|
|3-way splitter (unbalanced)||3.9 dB on one port and 7.5 dB on the other ports|
|4-way splitter||7.5 dB per port|
|8-way splitter||11.5 dB per port|
In a later article, we'll discuss how to design your installation to minimize losses, and when to consider using distribution amplifiers to help get the best signal quality to each TV set.