Syllabus Sections:-

9c Lightning Protection

9e.1 Recall that thunderstorms carry heavy static charges.

Understand that the static charge from thunderclouds can ionise the air to form a low resistance path to ground, enabling a very high current to flow as a lightning strike.

Understand the risks to human life, domestic property and electronic equipment associated with a direct strike and/or the build up of static charges.

Understand that there is little that can be done to protect an amateur station from a direct lightning strike, but that good static discharge systems can prevent dangerous static charges building up on antenna systems during thunderstorms.

Understand that disconnecting antenna feeders from radio equipment also reduces the risks.

heavy static charges

Your radio receiver whilst being selective cannot discern between a radio signal from a distant transmitter and the static build up from a thunderstorm. Cracks and pops can often be heard with other signals.

Consider these :-

• the cracks and pops can be very loud relative to the weak station audio and if you are wearing head phones damage to hearing can be a real possibility

• The sound of the static must alert you to the possibility of a near by lightning strike

• static charges are looking for a route to earth and that could be via your antenna feeder rig and earth line.

lightning

the static charge from thunderclouds can ionise the air to form a low resistance path to ground, enabling a very high current to flow as a lightning strike. This current can be many thousands of amps at high voltages so you have a double wammy to contend with.

There is no real protection from a direct lightning strike

• so there are real risks to human life especially if out doors on damp ground as the whole area can become "live",

• domestic property can be literally blown apart by a direct hit

• electronic equipment can be totally destroyed beyond recognition

Some degree of protection can be gained and can reduce the risks by :-

• having a good static discharge systems to your system, however this can be very expensive but it can prevent dangerous static charges building up on antenna systems during thunderstorms

• disconnecting antenna feeders from radio equipment

• provide an earth leakage route for the antennas to ground potential

Keep safe think about protecting your station

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