Outdoor antennas must be grounded for best reception and protection against lightning strikes. Indoor and attic antennas do not need to be grounded. However, when an indoor antenna cable is longer than 30 feet, some people recommend grounding the antenna/mast because it might help reduce static electricity build up which reduces reception.
ANTENNA RESTRICTIONS PROHIBITED
Federal law prohibits restrictions (by governments, community and homeowners' associations, and other entities) that impair the installation, maintenance or use of antennas used to receive video programming. Masts higher than 12 feet above the roofline may be subject to local restrictions. The FCC's webpage OTA Reception Devices Rule has more details, also see the Electronic Code of Federal Regulations webpage Title 47, Subchapter A, Part 1, Subpart S.
ANTENNA POINTING ANGLE
Point the antenna in the towers direction, commonly measured in degrees off of True North, several degrees different from Magnetic North for most locations. Magnetic north varies with location, and slowly changes over time. When using a compass to point an antenna, account for the difference between True and Magnetic north. The National Oceanic and Atmospheric Administration (NOAA) website has detailed information and a calculator for Magnetic Declination. Note that local conditions could effect a magnetic compass reading. If possible use landmarks to confirm or establish true north.
The antenna should be mounted as high as possible and have a clear line-of-sight (no hills, structures, trees, etc.) to the broadcast towers.
Mast are typically 18-gauge galvanized steel tubes that are 5 or 6 feet long with a 1.25 inch outer diameter. Some mast are designed to connect for extended length. A single section is strongest, two sections (10 or 12 feet) is acceptable in many locations.
Avoid installing near overhead utility lines, especially power lines. The power line electromagnetic fields can cause interference or signal reduction, and the lines are dangerous to work around.
Mast Ground Wire
COAX GROUND BLOCK
ANTENNA EARTH GROUND
The earth ground can be a ground rod (Figure 1), or the electrical service electrode ground system (Figure 2). The National Electrical Code (NEC Section 810) connects to the service ground. The service ground can be accessed by clamping the ground wire to the metal pipe running straight into the ground from the power meter or fuze / breaker panel. The ground wire can also be connected to the fuze / breaker panel ground bar instead of the pipe.
Figure 1 - Common Installation|
Figure 2 - NEC compliant Installation|
Some installations use an additional (optional but not required) ground rod close to the ground block, when the block is not close to the service ground. The NEC calls for a ground rod depth of 8 feet. A cold water metal pipe running into the ground makes a good ground (rod). Make sure the underground pipe is not plastic (PVC). The NEC specifies the ground connection be within 5 feet of the point the pipe enters the ground. The ground rod and service ground should then be connected with AWG 6 copper wire.
An antenna mast or cable within 5 feet of a swimming
AWG - American Wire Gauge
TOOLS AND PARTS LIST
Basic tools needed include a ladder and assorted screwdrivers, wrenches, sockets, and maybe a hammer etc. You will also need a wood and/or concrete drill, and appropriate drill bits and screws, for mast mounting.
A multiple antenna system requires a signal combiner / splitter to enable signals from all antennas to go down one cable. A signal splitter is (also) a signal combiner. Combining signals has the same loss as splitting signals, signal loss is the same for both directions. Also see Signal Splitters / Combiners loss.
TV Antenna Installation
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