MODULE, LIGHTNING ARRESTOR, for antenna

Complete lightning protection device for fixed HF/VHF/UHF radio installations.

The lightning protection device includes:

• 1 lightning protection box
• 1 earthing braid
• 1 earthing rod
• cabling and installation set

Lightning protection box ("fuse box")

• Metal box containing a fuse
• 2 UHF PL female/female connectors
• Mounted on a teflon plate allowing wall fixing

Earthing braid

• 10 mm²
• Non modifiable length, 10 metre

Earthing rod

• Made of copper only, no galvanised iron
• Non modifiable length: 1.50 metre

This lightning protection device MUST be installed for all radio equipment (one device per HF, VHF, and UHF radio).

If a radio room is equipped with one HF radio and one VHF radio, two lightning protection devices should be installed and connected separately to earth (never by means of one single earthing rod because of the risk of an earth loop and inter-radio interference).

Installation

The lightning protection box MUST be fixed OUTSIDE the radio room, as close as possible to the antenna, bearing in mind the length of the coaxial cable linking the radio and the lightning protection box (10 metre).

The earthing rod MUST be fully driven into the ground. The best way to proceed is to dig to a depth of 1.5 metre and to bury the rod. Putting charcoal into the hole along with earth will increase electrical conductivity.

Functioning

When lightning strikes the antenna mast, a strong electric current passes through it. This current will take the shortest and most conductive path to earth. As the current passes through the "fuse" box, the fuse cuts out and opens a path to the earthing strap (good conductor) and the earthing rod (excellent conductor) buried in the ground. The radio and other equipment connected to the coaxial cable are therefore protected.

If your antenna mast has been struck by lightning, the "fuse" box must always be replaced. Cables and connections must also be checked and any burned or damaged item replaced as soon as possible.

An unusally high Standing Wave Ratio, as read from the SWR meter (over 3) indicates a strong likelihood that the lightning protection box has been damaged by lightning.