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Know that all electronic equipment is capable
of radiating and absorbing radio frequency energy.
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Know that the basic principle of electromagnetic
compatibility is that equipments should limit radiation to below a specified
level and also be able to withstand a certain level of incident RF radiation.
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Know that the levels of RF radiation are given in
the EMC regulations.
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Know that transmitters in domestic environments
may give rise to RF fields stronger than the specified limits.
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Know that transmitters in domestic environments are
not 'normal' situations and special measures may have to be taken.
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Know that new electronic equipment should meet
the EMC immunity standards but that existing equipment and poorly installed
equipment may not.
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Know how to interconnect the transmitter, microphone,
power supply, SWR meter and band or low pass filters, using appropriate cables,
to minimise EMC problems.
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Know that filters can be fitted in the leads
from the power supply to the transmitter to help minimise RF energy entering
the mains wiring.
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Know what constitutes a good RF earth, its purpose
and use.
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Know how to use a suitable general coverage receiver
to check for spurious and harmonic emissions from the station.
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KNow that siting a transmitting antenna close
to mains wiring, TV or radio aerials and downleads is a potential problem
exacerbated by the use of a loft or indoor transmitting antenna.
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Know the forms of interference caused by amateur
radio and other radio transmissions: patterning on the TV screen, loss of
colour, voice on TV sound, radio, telephone or audio systems.
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Know that interference to digital televisions is different.
The picture may freeze, become jerky or disappear.
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Know that other sources of interference and their
effects: thermostats and vehicle ignition systems, electric motors in vacuum
cleaners, fans, drills, sewing machines etc. Spots on TV or radio sound.
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Know that direct pick-up in affected devices tends
to be independent of the transmitted frequency.
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Know that masthead and downlead TV amplifiers are
broadband and so they amplify a wide range of frequencies, including amateur
frequencies.
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Know that masthead and downlead TV amplifierscan overload
the TV input.
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Know that the use of ferrite ring filters for
minimizing unwanted RF on aerial downleads and mains leads to affected equipment.
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Know the use of high-pass filters to reduce the level
of HF and VHF amateur transmissions into TV systems.
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Know the use of mains filters to reduce RF, electric
motor and thermostat interference to TV, radio, and audio systems.
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Know that transmitting into a dummy load is a good
test for any unwanted RF being conducted out of the transmitter along its
power supply leads and into the mains.
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Know that the station log will be of considerable
assistance in confirming sources of interference to neighbours.
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Know the merits of the amateur and the complainant
keeping a log of the instances of interference.
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Know the merit of conducting tests in co-operation
with the complainant in instances of interference.
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Know the existence of and that advice is available
from the RSGB EMC Committee and the role of local RA officers in dealing
with cases of interference.
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Know that RA and the RSGB produce information leaflets
on EMC and interference.