Section 5.5: Antennas and Tower Safety #

Alright, antenna enthusiasts, let’s talk about keeping safe while getting those signals out! Even as Technician class operators, you might find yourself helping with antenna work, so it’s crucial to know the basics.

Tower Safety and Climbing #

When it comes to towers, safety isn’t just a good idea—it’s essential. If you’re planning to work on a tower, here’s what you need to know:

Key Information: When climbing an antenna tower, you must:
Have sufficient training on safe tower climbing techniques
Use appropriate tie-off to the tower at all times
Always wear an approved climbing harness
Have a helper or observer present

Never Climb Alone: It is never safe to climb a tower without a helper or observer. Your ground crew isn’t just there to hand you tools—they’re your safety net. They can call for help in an emergency, guide you through difficult maneuvers, and keep an eye on changing conditions like approaching weather.
Proper Equipment is Non-Negotiable: When climbing a tower, you must have sufficient training on safe tower climbing techniques, use appropriate tie-off to the tower at all times, and always wear an approved climbing harness. This isn’t the place to cut corners or improvise.
Crank-Up Tower Special Rules: A crank-up tower must not be climbed unless it is retracted, or mechanical safety locking devices have been installed. These towers aren’t designed to be climbed when extended without proper locking mechanisms in place. The telescoping sections can collapse if improperly secured, leading to catastrophic results.

Here’s a real-life scenario: A ham decided to make a “quick adjustment” to his antenna on a crank-up tower without retracting it or using the safety locks. A sudden gust of wind caused the tower to shift slightly, and the unsecured sections began to telescope downward. Fortunately, he wasn’t on the tower at the time, but his expensive antenna system wasn’t so lucky!

Overhead Power Lines and Placement #

Key Information: Always look for and stay clear of overhead electrical wires when putting up an antenna tower

Power lines are the arch-nemesis of antenna safety. When putting up an antenna tower, always look for and stay clear of any overhead electrical wires. Here’s a rule of thumb:

Key Information: The minimum safe distance from a power line to allow when installing an antenna is enough so that if the antenna falls, no part of it can come closer than 10 feet to the power wires

So if you’re putting up a 20-foot vertical, that’s 30 feet minimum from any power lines.

Key Information: You should avoid attaching an antenna to a utility pole because the antenna could contact high-voltage power lines

Even if it seems convenient, it’s just not worth the risk. Utility poles often carry multiple electrical lines, some carrying thousands of volts. An antenna that touches these lines can energize your entire system, creating a deadly hazard.

Guy Wires and Structural Support #

Tall towers often need guy wires to keep them standing strong. But there’s a small but important detail—if the turnbuckles (the metal adjusters that tighten the guy wires) loosen due to vibration, the whole structure could be at risk!

Key Information: The purpose of a safety wire through a turnbuckle used to tension guy lines is to prevent loosening of the turnbuckle from vibration

The fix is simple: after adjusting the turnbuckle, thread a thin safety wire through its holes and twist the ends together. This keeps it from spinning loose over time. Just a little wire can make the difference between a steady tower and a dangerous collapse!

Grounding Systems and Lightning Protection #

Proper grounding is essential for both safety and equipment protection. Here’s what you need to know:

Key Information: When installing ground wires on a tower for lightning protection, ensure that connections are short and direct

Key Information: A lightning arrester should be installed on a grounded panel near where feed lines enter the building

This placement allows it to intercept lightning energy before it can enter your home or shack. While no system can fully protect against a direct lightning strike, a properly installed arrester can significantly reduce the risk to your equipment and home.

Key Information: All external ground rods or earth connections should be bonded together with heavy wire or conductive strap

This ensures that lightning energy finds a direct path to ground instead of traveling through your equipment looking for an alternative route.

Key Information: A proper ground method for a tower is separate eight-foot ground rods for each tower leg, bonded to the tower and each other

This provides multiple paths to earth ground, reducing ground resistance and improving lightning protection – it also reduces the chance of lightning seeking other paths to ground, such as the mounting hardware holding the tower in place!

Key Information: Flat copper strap is the preferred conductor for RF bonding

Due to the skin effect (where RF currents travel on the surface of conductors), a flat strap provides more surface area and lower impedance than a round wire of the same cross-sectional area.

Key Information: When installing grounding conductors used for lightning protection, sharp bends must be avoided

Lightning follows the path of least resistance, and sharp bends can create high impedance points that may cause the energy to arc or find an alternative path.

Key Information: Local electrical codes establish grounding requirements for an amateur radio tower or antenna

These aren’t just suggestions—they’re legally required standards designed to keep you and your property safe. Always consult and follow your local electrical code when installing antennas and towers.

Safety first when working on antennas! #

Remember, the goal is to make contacts and have fun, not to star in the next “What Not to Do” video at your local ham club. Antenna work can be exciting and rewarding, but it needs to be done with a healthy dose of respect and caution.

So, before you start raising that antenna for your first VHF/UHF adventures, take a moment to think safety. Your fellow hams, your radio gear, and most importantly, you, will be better off for it.

Stay safe, keep those antennas high (but not too close to power lines), and happy operating on those VHF and UHF bands!