Off-Air Antenna Installation Training

1

Off-Air Antenna Installation Training

2

Overview

• Why install off-air antennas

• Basics of off-air broadcasts

• Antenna Characteristics

• Basic Rules of off-air broadcasts

• DIRECTV approved antennas

• Safety, Preparation, and Installation

• Installation Considerations

• Troubleshooting

• Using Antennaweb

• Commonly Used Terms and Additional Resources

3

Why install off-air antennas

• To allow a customer to view their local area

broadcast channels either in standard or High

Definition

4

Basics of off-air broadcasts

• Over-the-air (OTA) channels are broadcast by local

television stations.

• This signal is broadcast from a transmitter tower. The

signal travels in the air across the surface of the earth in all

directions within a specified area.

• There are two ways of sending the signal: analog and

digital. Analog broadcasts have in most areas been turned

off

5

Basics of off-air broadcasts

• The signal broadcast from the TV tower use to cover channels 2 thru

13 (55MHz to 211MHz) & 14 thru 69 (471MHz to 800MHz) – the

Analog days

• With the move to Digital, the TV broadcasters now utilize channels 14

to 51

• Channels 52 – 69 have been re-assigned by the FCC for other purposes

• An off-air antenna is used to gather these signals and send them to the

ATSC off-air tuner which can sometimes be built into the TV its self.• Since digital TV signals are more "economical" than analog TV signals,

digital signals are able to carry more information while taking up less space as compared to analog signals. With Digital, television broadcasters have the ability to offer more features and more programming (more virtual channels) on their assigned frequency channel.

6

Basics of off-air broadcasts• An ATSC tuner is required to receive digital off-air

broadcasts.

• A digital off-air tuner, which can be either the TV’s tuner or

a tuner built in to a standalone receiver, or an AM-21

• AM-21 uses a USB cable to connect to an HR21/H21 and

newer receiver

• Both the H20 and HR20 have the ATSC tuner built

7

Antenna Characteristics

• There are many types of antennas available on the

market with varying characteristics. These

characteristics are usually described on the antenna

model’s specification sheet. Antennas are also grouped

by a color coding system which is useful in picking an

antenna with specific characteristics. Antennas are

usually described by their:

– Gain

– Directivity

– Beamwidth

– If it is amplified or non-amplified

8


Gain – Describes the available signal

increase of a specific antenna when

compared to another antenna.

9


Directivity – The antenna’s

ability to intercept signals

from one direction and ignore

those from another direction.

Directivity may be referred to

as directionality. The antenna

shown in this image is highly

directional.

10


Beamwidth – The area from which the

antenna can receive and output signals at

approximately equal levels. This area is

described in degrees, and is formed from the

compass angles outlining the area’s

boundary. Usually, the narrower the

beamwidth of an antenna, the greater its

directivity and gain.

11

Antenna CharacteristicsAmplified vs. Non-Amplified

– Amplified antennas do not increase the range of the antenna.

Rather, they should be used when the signal strength is already of

a good quality, but too much cable loss occurs by the time it has

reached the off-air tuner due to long cable runs or multiple pieces

of in-line equipment.

– An antenna that includes a signal amplifier is often referred to as

having a “preamp”. This means that the amplifier is built into the

antenna, rather than being a separate line amplifier.

12

Antenna Selector Pie Chart

This pie chart is used to classify

antennas according to their

reception range and directivity.

These colors match up to those

used on www.antennaweb.org

in making a recommendation

on the antenna required to

receive a particular channel in

a particular area.

ANTENNA SELECTOR PIE-CHART LEGENDYELLOWThe smallest of TV antennas, these receive equally well from all directions. Designs include novel-shaped disks, patch antennas and antennas that attach to satellite systems. These antennas are most effective when signal strength is highest and away from reflecting structures or low areas.

DARK GREENIntermediate in both size and power, these antennas receive equally in all directions. Designs include novel stick, wing-shaped or disk-type antennas with long elements. An amplified antenna is recommended for green channels anytime a long (20 feet or more) cable from the antenna is required, or when more than one device (TV or VCR) is to be used with an antenna. They work best away from reflecting structures or low areas.

LIGHT GREENBigger in size, these antennas boast powerful reception in all directions. These antennas are better for greater distances from the signal source and areas with low signal strength. Styles include metal multi-element antennas. These antennas can be used to reject simple ghost situations. When mounted outdoors on rooftops heights (30 feet or higher), amplified antennas are best used in areas away from reflecting structures or low areas.

REDThese medium-size, multi-element antennas are the most popular rooftop antenna because of their modest size and ghost-reducing characteristics. These are best used if there are any ghost-producing reflective structures near your location.

BLUE, VIOLET & PINKThese are LARGE DIRECTIONAL antennas. (The antennas in the pink and the violet zones require a preamp)Large directional antennas can be used in all map areas yellow through blue, but may require an optional antenna mounted preamp and roof-top mounting when used in violet or pink areas.

http://www.antennaweb.org/

13

Basic Rules of Off-Air Reception

• Outdoor antennas are better – These antennas have a better view

of the transmitting station, receive less interference from other

equipment, and are less subject to multi-pathing from the building

structure

• Higher is better – The higher the antenna’s position, the more

direct signal it receives from the transmitting station

• Closer is better – The antenna should be on the side of the building

that faces the broadcast tower

• Bigger is generally better – The larger an antenna, the more signal

it generally receives

DIRECTV Approved Antennas

Eagle Aspen Part # DTV2BUHF

Used within Metropolitan areas < 25 miles

Winegard Sensar III Bi-directional Part # GS-1100

For use from 0 - 25 miles

Winegard Metrostar Omni –directional Part # MS2000

For use from 15 - 35 miles

• DTV2BUHF – 2BAY UHF ANTENNA (This antenna will work with the 2” mast but does not work with VHF frequency ranges channel designation 2-13)

OTA Antenna Installation

• The existing standard 2” mast with an ODU will not properly accommodate the off-air assembly.

• In many cases the installation will require a second mast to be installed at the customer’s home to accommodate the additional off-air antenna.

• DIRECTV will try to ship as many 1-5/8” masts to the affected markets as possible to aid in installation.

• The current antennas were designed to fit our previous 1-5/8” mast and only DTV2BUHF will bolt properly to the new 2 inch mast assembly.


• In order to attach the MS1000D or GS1100 assembly you may be required to remove the pole clamp to enable the included U-bolt to attach to the 2” mast if a 2” mast is used.


• This installation may require a self-tapping screw to keep the antenna from spinning on the pole or moving up and down on the mast.

• The other option is to replace the existing U-bolt with a 4” U-bolt


• Moving forward, the antenna manufacturer will include the 4” U-Bolt along with the existing 3” U-bolt with the GS1100.

• You will need to use the longer U-Bolt when attaching the antenna to the 2” standard foot and mast or any of the other DIRECTV approved 2” alternative mounts once the option is included in the packaging.

• Please do not attach the antenna to the existing ODU mount.

• Unless absolutely necessary, a separate mount should be used for the OTA antenna.

19

Safety Considerations

• Follow all safety rules and regulations you normally follow

for installation of satellite dishes. In addition to those rules:

– Locate and avoid any power lines or other wiring in the

area.

– Antennas can not be installed closer to a power line the

twice the combined length of the antenna and mast.

– Any antenna mounted on a mast 20 feet or higher

requires more than one person to install.

– The antenna mast and cable must be grounded in

accordance with the National Electric Code.

– Masts over 10 feet tall require guy wires every 10 feet.

20

Steps to choose and install an antenna

1. OTA channels desired and available

2. Pick antennasto bring to thejob site(at the office)

3. Preparation and printouts(at the office)

4. Site Survey(at the customer’s home)

5. Discuss anticipated channels withcustomer

6. Assemble and mount the antenna

7. Point antenna

8. Ground antenna andrun cabling

9. Scan channels usingreceiver

10. Verify scannedchannels matchanticipated channels

11. Fine tune the antenna, if necessary

12. Clean up

21

1. Determine the availability of off-air channels

If a customer expresses an interest in

receiving off-air channels, go to

www.antennaweb.org and click the

“Choose an antenna” button. This tool

predicts the off-air channels that may be

available using the address, whether

there are structures over 4 stories tall,

and the building structure. Enter the

customer’s address and click “Submit”.


22


Antennaweb.org provides you with a

list of available channels, the

antenna required to pick up each

specific channel, and the signal

direction for each channel. Click

here for a detailed explanation of

how to use Antennaweb.

23


Since the customer is interested in receiving off-air high

definition programming, click the “Show Digital Stations

Only” button. “View Street Level Map” provides a map of

the transmit station locations relative to the customer’s

address. Discuss the list of available channels with the

customer to determine if an off-air antenna can provide

the desired channels.

24

2. Pick Antenna(s)

Using the street level map and channel list,

choose the antennas to bring to the

customer’s home. For this customer’s

location, a medium directional antenna

(color code red) would likely provide access

to many channels broadcast from the

north-west, but may not allow reception of

the channel broadcast from the south-east.

25

2. Pick Antenna(s)

Always bring at least two or three

types of antennas with different

beamwidths, gain and directivity to

the customer’s home. Pick

antennas that should allow

reception of the desired channels

based on the information from

Antennaweb.

26

2. Pick Antenna(s)

• Picking a specific color-coded antenna does not guarantee

you will receive all channels that also use that color-coded

(or smaller) antenna. The channels received are also

determined by the direction in which the antenna points.

• Additional considerations that may be evident when

arriving at the customer’s home will help you to choose

which antenna to install. These considerations will be

determined by performing a thorough site survey at the

house.

27

3. Preparation and Printouts

Using antennaweb, click on “View

Street Level Map”, then click

“Printer Friendly Map”. Print the

map and the list of digital channels

for the customer’s address to take

with you to the job site. The map

and channel list will be used while

performing the site survey and

pointing the antenna.

28

3. Site Survey

• The site survey should be performed using a compass and the

compass orientation provided by Antennaweb.org. If possible, the

antenna should be mounted near to the satellite dish. When

performing the survey, keep the following considerations in mind:

– Natural Obstacles (Hills, Trees, etc.)

– Man Made Obstacles (Tall buildings, houses)

– Reflective Surfaces

• Obstructions between the antenna and the broadcast stations may

cause a reduction or complete loss of signal.

29

4. Discuss anticipated available channels with the customer

• Based on the customer’s location and surrounding

terrain, it may not be possible to receive all off-air

channels.

• After determining the off-air channels that will

likely to be received from the Antennaweb.org

information and your site survey, discuss the

expected channels with the customer.

30

5. Assemble and mount the antenna

• Assemble the antenna following the

installation instructions that came with that

equipment.

• Find a location on the customer’s home that

has line of sight to the transmit towers.

• Install the antenna as high as possible to

avoid obstructions.

31

6. Point the antenna• Peak the antenna using the highest

desired channel frequency (shown as

“frequency assignment” on the

channel list from Antennaweb.org).

• Once you have pointed the antenna,

check all desired channel frequencies

for signal.

32

7. Ground the antenna and cabling run

• Both the antenna mast and the transmission line must be

grounded to meet the National Electric Code, State, and any

local requirements.

• RG-6 coaxial cable is preferred.

• Note: a single RG-6 coaxial cable must be ran from the off

air antenna to the ATSC tuner

33

8. Verify available channels

Verify availability of desired channels found

using the receiver’s Local Channels scan. These

results should match what was expected from

the site survey and Antennaweb.org

34

9. Fine-tune the antenna alignment

• If not all expected channels are

found, adjust the antenna’s alignment

until the expected channels are

available.

• Azimuth fine-tuning - you may need

to adjust the compass orientation

(azimuth) setting of the antenna.

35

10. Fine-tune the antenna alignment

• Depending on your location and that of the

transmitter towers, you may need to compromise

how the antenna is pointed to receive the desired

channels. It may not be possible to receive all

desired channels, or using an antenna with

different characteristics (beamwidth, directivity,

gain) may be required.

36

11. Clean Up

• As always, once the installation is

complete, clean up any

packaging, loose cabling, and

tools that were used during the

installation.

37

Important Installation Considerations

Terrain – The landscape surrounding the customer’s home has

many impacts on their ability to receive off-air channels. For

instance, if a broadcast station is behind a large hill from the

customer’s location, it may not be possible to receive the

channel from that broadcast station. Trees and other natural

objects may also interfere with the reception of off-air signals.

38


Obstructions – In addition to the terrain, man-made

obstructions, such as buildings and other houses, may be

between the customer’s location and the broadcast station.

These objects may prevent the signal from reaching the

customer’s antenna, or they may cause signal to be reflected,

resulting in multipathing.

39


Multipathing – Multipathing occurs

when the signal from the broadcast

station reaches the antenna at

varying times. This often occurs

when the antenna receives the signal

sent directly from the station, but

also receives the same signal

reflected by another object.

40


• Distance from the broadcast station – The longer the broadcaster’s

signal travels, the weaker it will be. Choosing the right antenna for

the desired channels will help.

• Digital off-air broadcasts are still in their infancy. This leads to some

additional considerations that may impact what channels the

customer may receive.

– Many broadcasters do not yet have permanent broadcast stations.

– Broadcasters are not yet legally required to provide full-time digital

signals.

– Some digital channels may not broadcast all the time.

41

Troubleshooting

• This troubleshooting section lists

commonly experienced issues with

the most common resolutions.

• Match the symptom of what you are

experiencing or seeing on the screen

for troubleshooting steps for the

issue.

42

Troubleshooting - Interference

Herringbones or images from another channel -

Occurs when another channel is on a close

frequency. A directional antenna may be required,

or traps and filters can solve the problem.

1. Try adjusting the antenna’s alignment or location.

2. Try using a more directional antenna.

3. Try using traps or filters.

43


Co-channel interference - Occurs when

another station is broadcasting on the same

frequency, and is usually resolved by using a

directional antenna.

1. Try adjusting the azimuth of the antenna

2. Try relocating the antenna

3. Try using a more directional antenna

44


Electromagnetic interference – Bright static

across the screen with a whining or grinding

noise that is often caused by appliances and

power lines.

1. If the source of the interference is outside the

home, try using a more directional antenna.

2. Try unplugging from the electrical outlet each

device in the home that could be causing the

interference.

3. Contact the power company.

45


CB / Ham Radio Interference – Rolling, fading, or

disappearing picture, with the voices of the radio

operator in the TV audio.

1. If you can identify the source of interference,

contact the person and inform them of the

interference.

2. Contact the FCC if you can not identify the

source.

3. A high pass filter (one that eliminates

frequencies below 54 MHz) may need to be

attached to the input of the receiver.

46


Airplane flutter – Rolling picture

or a picture that fades in and

out, often occurring when in the

flight path of low-flying

airplanes or near an airport.

1. Try using a highly directive

antenna.

47

Troubleshooting

• Multipath – Multipathing occurs when a reflected signal is

received at a different time from the primary signal.

Multipathing can appear on one channel but not on others

due to the differences in frequency and wavelength of the

channel.

– Multipathing will show up as freezes in video or pixelizing.

– Avoid installing an antenna adjacent to a structure that could

reflect the signal, such as a large building or structure.

– Install a more suitable antenna for the location. A more

directional antenna will block multipath better than a less

directional antenna.

48

Troubleshooting – Proper use of amplifiers

• If you have a strong signal reading at the antenna, but

have low signal by the time it reaches the receiver,

you may need to consider using an amplifier.

• Amplifiers only compensate for signal loss due to long

cable runs or pieces of in-line equipment, such as

splitters.

• If you are not receiving adequate signal readings at

the antenna, this indicates that the antenna needs to

be peaked or a different antenna may be required. An

amplifier would not help for this situation.

49

Using Antennaweb.org

Antennaweb is a great

reference for picking and

installing off-air antennas.

After entering a customer’s

address, you will receive a

screen similar to the one to

the right.

50

Using Antennaweb

On this screen, you have the option to see the list of all

channels, only digital channels or only analog channels,

and view a street level map of the transmitter towers

relative to the address you entered. Each channel also

lists information helpful in picking and pointing the

antenna, which is described on the next slides.

51

Using Antennaweb

1. A star (*) under DTV indicates the channel is broadcasting a digital signal.

2. Antenna type is color coded according to the Antenna Selector Pie Chart, and

also lists if the antenna needs to pick up UHF or VHF signals to receive that

channel.

3. Call sign is the channel call letters. In addition to the call letters, some channels

have additional letters following the call sign. In this example, “-DT” indicates a

digital signal. You may also see “-LP” for low power, or “-CA” for Class A stations.

4. Channel is the channel number assignment that would show up in the satellite

receiver’s Program Guide. The “.1” indicates the channel has the ability to

multicast.

321 4

52

Using Antennaweb

5. Network indicates the channels network affiliation.

6. City and State are the location from which the channel is broadcast.

7. Live Date may be blank if the channel is already active. It will list “TBD” if

it is not yet determined if the channel is active, a date in the future when

it is scheduled to be available, or “Testing” if the channel is testing their

digital signal.

8. Compass Orientation is the direction in which the antenna needs to

point to receive the signal. This is similar to the azimuth angle used

when point satellite dishes.

8765 6

53

Using Antennaweb.org

9. Miles From indicates the distance from the address you entered to the

transmitter tower. This distance helps you to determine the antenna to

use. For instance, you could not use an antenna with a range of 30 miles

to pick up a channel broadcast from 50 miles away.

10. Frequency Assignment is the actual frequency on which the channel is

broadcast. This may or may not correspond to the channel number listed.

The Frequency assignment should be used when peaking the antenna,

rather than the channel number.

109

54

Commonly Used Terms

• Amplifier – Boosts the strength of received signal but does not increase

antenna range. Amplifiers are use to account for signal loss due to long cable

runs or in-line equipment, such as splitters. An amplifier for an antenna can be

either a “line amplifier”, meaning it is installed on the coax cable running to the

receiver, or a “preamp” (preamplifier), which is built into the elements of the

antenna. Both types of amplifiers require a power inserter to be installed.

• Attenuation – A decrease in strength of a signal as it is transmitted by wires

from one point to another. Also referred to as cable loss.

• Beamwidth – The area in which the front of an antenna can intercept signals,

which is formed by the compass angles outlining the area’s boundary.

• Directivity – The ability of an antenna to pick up signals from one direction

while ignoring those received from other directions.

• Frequency Assignment – Indicates the frequency on which that channel

broadcasts. This number does not necessarily correspond to the channel

number.

55

Commonly Used Terms

• Gain – An increase in signal strength, which indicates how much more signal

it delivers than a single element antenna under the same conditions.

• Multicasting – A digital channel can use all of its bandwidth to broadcast

either one station in high definition (HD), or multicast up to four alternative

standard definition stations in the same bandwidth. The primary channel

shows with a “.1” at the end. If the station multicasts, there would be three

additional channels, with the same primary channel number, but having “.2”,

“.3”, and “.4” at the end. Many digital stations choose to multicast during the

day, and then will switch to an HD feed for primetime.

• Multipath – Occurs when the signal from the broadcast station reaches the

antenna at varying times. This often happens when the antenna receives the

signal sent directly from the station, but has another object reflecting the

signal back to the antenna.

• OTA – An abbreviation used that refers to over-the-air channels.

56

Commonly Used Terms

• Propagation Type – Classifies antennas based on the direction from which they can receive

off-air signals.

• Polar Plot – A graph that identifies the antenna’s

characteristics such as beamwidth or directivity.

The two polar plots shown here

illustrate the beamwidth and directivity of

a directional antenna, or one that picks up channels

only from one direction, and a bi-directional antenna, or one that picks up channels from

two directions.

• Transmit Towers – Used by the TV station to broadcast the TV signal

• UHF – Ultra-high frequency channels are those from channels 14 through 69, whose

frequencies are located in the UHF band. Digital off-air channels are usually found in this

range.

• VHF – Very-high frequency channels are those from channels 2 through 13, whose

frequencies are located in the VHF band. VHF is sometimes broken into two segments: low

VHF (ch 2-6), and high VHF (ch 7-13).

57

Helpful Links

• www.antennaweb.org – Use this website to look up recommended

antennas, get information about antenna reception patterns, and answers

to frequently asked questions.

• http://www.winegard.com/offair/index.php – Provides information and

specifications on the antennas listed in this training, as well as answers to

frequently asked questions.

• http://www.fcc.gov/mb/facts/otard.html - Provides information on off air

antennas

• http://www.hdtvprimer.com/ANTENNAS/basics.html - Provides

information on TV broadcasts and commonly used terms and equipment.


http://www.winegard.com/offair/index.php

http://www.fcc.gov/mb/facts/otard.html

http://www.hdtvprimer.com/ANTENNAS/basics.html

http://www.hdtvprimer.com/ANTENNAS/basics.html

Off-Air Antenna Installation Training

Documents

Transcript of Off-Air Antenna Installation Training