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Syllabus Sections:- Working with RF 8D1 51
Recall that the International
Commission for Non Ionising Radiation Protection
(ICNIRP) produces guidance for exposure to Radio
Frequency fields. 8D1 51 continued Understand it is not advisable to exceed the recommended safe exposure levels and that this is particularly applicable at location open to the public Please check for current advisable limits for exposure, but as of May 2021 the level set for UK EMF exposure is 28V/m ,this needs to be used when setting up any field day when the public may be visiting and there may be a need for some form of physical barrier. The barrier will prevent people getting too close to a radiating antenna and prevent accidents with any falling masts as a bonus ! Use the safe exposure rules as a general "must do" when using ham radio equipment both in the shack and out and about. ----------------------------------------------------------------------------------------------------------------- Lightning 8E1 51 Recall that thunderstorms carry 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. 8E1 51 continued 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. 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 whammy with which to contend.8E1 51 continued Understand the risks to human life, domestic property and electronic equipment associated with a direct strike and/or the build up of static charges. Thunderstorms can destroy Ham radio electronic equipment via static discharge and the huge magnetic fields generated by it, they also can cause death via arching from your equipment to you in the event of a direct strike.Domestic property can be completely destroyed by a direct strike. --------------------------------------------------------------------------------------------------------------- 8E1 51
continued 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. There is no
real protection from a direct lightning strike 8E1 51 continued Understand that disconnecting antenna feeders from radio equipment also reduces the risks. Some degree of protection can be gained and can reduce the risks by :- • having a good static discharge systems connected to your station, 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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