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Subelement T0
Electrical safety: AC and DC power circuits; antenna installation; RF hazards
Section T0B
Antenna safety: tower safety and grounding; erecting an antenna support; safely installing an antenna
When should members of a tower work team wear a hard hat and safety glasses?
  • At all times except when climbing the tower
  • At all times except when belted firmly to the tower
  • Correct Answer
    At all times when any work is being done on the tower
  • Only when the tower exceeds 30 feet in height

It only takes one time that you don't use safety equipment to cause permanent injury or death. The small inconvenience of a hard hat and safety glasses is not worth the risk of injury. Find your motivation , stay safe, and do not die.

Last edited by brendan.m.mccarty. Register to edit

Tags: safety arrl chapter 9 arrl module 22

What is a good precaution to observe before climbing an antenna tower?
  • Make sure that you wear a grounded wrist strap
  • Remove all tower grounding connections
  • Correct Answer
    Put on a carefully inspected climbing harness (fall arrester) and safety glasses
  • All of these choices are correct

Safety comes first in regards to tower work. Make sure that your climbing harness is in working order, fitted tightly and comfortably, and you have safety glasses protecting your eyes.

In addition, a pair of cut resistant gloves would be wise. You don't want any punctures, lacerations, or burns (if you live in a hot, sunny climate) while climbing.

Also, tuck in baggy clothes and remove jewelry or anything that may snag on tower components.

Last edited by bmags96. Register to edit

Tags: safety arrl chapter 9 arrl module 22

Under what circumstances is it safe to climb a tower without a helper or observer?
  • When no electrical work is being performed
  • When no mechanical work is being performed
  • When the work being done is not more than 20 feet above the ground
  • Correct Answer
    Never

Always take the time to get someone to help. Never climb a tower without someone else to help or observe.

Last edited by floresea. Register to edit

Tags: safety arrl chapter 9 arrl module 22

Which of the following is an important safety precaution to observe when putting up an antenna tower?
  • Wear a ground strap connected to your wrist at all times
  • Insulate the base of the tower to avoid lightning strikes
  • Correct Answer
    Look for and stay clear of any overhead electrical wires
  • All of these choices are correct

A grounded wrist strap is for use on electronics and won't help when working on a tower. Insulating the base won't stop lightning strikes and eliminates the grounding system that protects the tower. The only answer that is an important safety precaution is to look for and stay clear of overhead electrical wires. The tower, guy wires and you should be well clear of any overhead electrical wires. Refer to question B06 for more information on safe distances.

Last edited by uhammes. Register to edit

Tags: safety towers arrl chapter 9 arrl module 22

What is the purpose of a gin pole?
  • To temporarily replace guy wires
  • To be used in place of a safety harness
  • Correct Answer
    To lift tower sections or antennas
  • To provide a temporary ground

A gin pole is a temporary mast that is used to lift materials for tower construction. It also supports the materials while they are installed on the tower. It is much safer than lifting materials directly because you can focus on the installation instead of the heavy lifting.

For a diagram and more detailed explanation see "The gin pole: Solution in erecting antenna masts" on iw5edi.com.

Last edited by mk2019. Register to edit

Tags: safety towers arrl chapter 9 arrl module 22

What is the minimum safe distance from a power line to allow when installing an antenna?
  • Half the width of your property
  • The height of the power line above ground
  • 1/2 wavelength at the operating frequency
  • Correct Answer
    Enough so that if the antenna falls unexpectedly, no part of it can come closer than 10 feet to the power wires

None of the other three answers provide any indication of how close the antenna will be to the power line if it falls. Note that this is the minimum and should only be used when necessary. It is better to create more distance than the 10 foot minimum whenever practical.

Last edited by orangutan01923. Register to edit

Tags: safety arrl chapter 9 arrl module 22

Which of the following is an important safety rule to remember when using a crank-up tower?
  • This type of tower must never be painted
  • This type of tower must never be grounded
  • Correct Answer
    This type of tower must not be climbed unless retracted or mechanical safety locking devices have been installed
  • All of these choices are correct

Obviously, the tower must be grounded. Clearly, the important safety precaution is to not climb the tower unless fully retracted. Climbing the tower requires that your hands and feet are placed between the parts of the tower that slide adjacent to each other. You can think of the tower as a possible guillotine that can severely injure and even remove body parts that are in the way if it accidentally slips. Even when retracted, it is a good idea to block the tower to prevent the sections from moving.

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Tags: safety towers arrl chapter 9 arrl module 22

What is considered to be a proper grounding method for a tower?
  • A single four-foot ground rod, driven into the ground no more than 12 inches from the base
  • A ferrite-core RF choke connected between the tower and ground
  • Correct Answer
    Separate eight-foot long ground rods for each tower leg, bonded to the tower and each other
  • A connection between the tower base and a cold water pipe

The general idea of grounding a tower is to provide a short, direct path for high voltage/current lightning strikes to ground. If a single ground rod is used, it increases the distance required and drops the efficiency of the grounding system. A single four-foot grounding rod is not adequate to handle typical electrical energy generated in a lightning strike. Clearly, the ferrite-core RF choke is of no use, as it is used in electronic circuits. In addition to that, connecting the tower to a cold water pipe poses a serious safety concern for people who might be near the plumbing in the house the water pipe connects to. The best answer is long (8-10ft) grounding rods, one for each tower leg, that are bonded to the tower and to each other.

Last edited by nbiggers2023. Register to edit

Tags: grounding safety towers arrl chapter 9 arrl module 22

Why should you avoid attaching an antenna to a utility pole?
  • The antenna will not work properly because of induced voltages
  • The utility company will charge you an extra monthly fee
  • Correct Answer
    The antenna could contact high-voltage power lines
  • All of these choices are correct

It should be pretty obvious that any antenna should be far away from power lines, both to avoid accidental contact and to avoid interference. Also consider that installing and maintaining the antenna exposes you to the risk of accidental contact with the power wires as well.

The all are correct answer, however, is false. First the answer about 60Hz radiations affecting the SWR says they are coming from the feed line, when they actually would be coming from the power lines. Second, induced currents in the antenna might damage the transceiver if they were strong enough, or be received as static or unwanted noise (aka, interference) if they were at the right frequency, but this does not mean the antenna would be malfunctioning per se: The antenna would actually be functioning exactly as intended, turning radio waves into electricity.

Last edited by the_lab_cat. Register to edit

Tags: safety antenna arrl chapter 9 arrl module 22

Which of the following is true when installing grounding conductors used for lightning protection?
  • Only non-insulated wire must be used
  • Wires must be carefully routed with precise right-angle bends
  • Correct Answer
    Sharp bends must be avoided
  • Common grounds must be avoided

Sharp bends, which includes right angles, must be avoided. While non-insulated wire is generally used for grounding, it is not required. For example, metal straps may be used instead of wires, but you won't see this commonly. Common grounds are recommended. The best grounding system uses conductors that are as short and straight as possible.

"Short and Direct"

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Tags: safety grounding arrl chapter 9 arrl module 22

Which of the following establishes grounding requirements for an amateur radio tower or antenna?
  • FCC Part 97 Rules
  • Correct Answer
    Local electrical codes
  • FAA tower lighting regulations
  • UL recommended practices

Because the grounding system falls under an electrical installation, it is governed by local electrical codes. Most local codes are based on the National Electrical Code (NEC), so in most cases they will just refer you to the NEC. You should be aware that local codes vary dramatically throughout the United States in terms of who can inspect and approve electrical installations, so it's always a good idea to check with your local code enforcement office to find out what the requirements are.

In Article 100 of the NEC, the local electric codes are governed by the term Authority Having Jurisdiction (AHJ), which is defined as “An organization, office, or individual responsible for enforcing the requirements of a code or standard, or for approving equipment, materials, an installation, or a procedure.” Grounding requirements would fall under their jurisdiction.

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Tags: rules and regulations grounding towers antenna arrl chapter 9 arrl module 22

Which of the following is good practice when installing ground wires on a tower for lightning protection?
  • Put a loop in the ground connection to prevent water damage to the ground system
  • Make sure that all bends in the ground wires are clean, right-angle bends
  • Correct Answer
    Ensure that connections are short and direct
  • All of these choices are correct

Use large wires over short distances on a direct path to the grounding rods - Lightning is high voltage, high current electricity, short and direct paths will lessen the chance of electricity to jump to nearby conductors.

The answers of using loops and right angles are the opposite of using short and direct connections. Lightning is high voltage, high current electricity.

Bends in the wire may allow the electricity to 'jump' from the wire to nearby conductors, thereby defeating the grounding system.

The longer the wires are, the more resistance there is and the hotter the wire will get.

Once again: Use large wires over short distances on a direct path to the grounding rods - short and direct.

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Tags: grounding safety arrl chapter 9 arrl module 22

What is the purpose of a safety wire through a turnbuckle used to tension guy lines?
  • Secure the guy if the turnbuckle breaks
  • Correct Answer
    Prevent loosening of the guy line from vibration
  • Prevent theft or vandalism
  • Deter unauthorized climbing of the tower

You tighten turnbuckles by turning them, but with vibration, they can come loose. The safety wire keeps them from turning, once they're tight.

They won't help if the turnbuckle breaks - they're too fragile.

They won't prevent theft or vandalism because they're easily removed.

They have nothing to do with climbing the tower, because they're just used on the turnbuckles.

Last edited by kd7bbc. Register to edit

Tags: arrl chapter 9 arrl module 22

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