Know that all electronic equipment is capable
of radiating and absorbing radio frequency energy.
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.
Know that the levels of RF radiation are given in
the EMC regulations.
Know that transmitters in domestic environments
may give rise to RF fields stronger than the specified limits.
Know that transmitters in domestic environments are
not 'normal' situations and special measures may have to be taken.
Know that new electronic equipment should meet
the EMC immunity standards but that existing equipment and poorly installed
equipment may not.
Know how to interconnect the transmitter, microphone,
power supply, SWR meter and band or low pass filters, using appropriate cables,
to minimise EMC problems.
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.
Know what constitutes a good RF earth, its purpose
Know how to use a suitable general coverage receiver
to check for spurious and harmonic emissions from the station.
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.
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.
Know that interference to digital televisions is different.
The picture may freeze, become jerky or disappear.
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.
Know that direct pick-up in affected devices tends
to be independent of the transmitted frequency.
Know that masthead and downlead TV amplifiers are
broadband and so they amplify a wide range of frequencies, including amateur
Know that masthead and downlead TV amplifierscan overload
the TV input.
Know that the use of ferrite ring filters for
minimizing unwanted RF on aerial downleads and mains leads to affected equipment.
Know the use of high-pass filters to reduce the level
of HF and VHF amateur transmissions into TV systems.
Know the use of mains filters to reduce RF, electric
motor and thermostat interference to TV, radio, and audio systems.
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.
Know that the station log will be of considerable
assistance in confirming sources of interference to neighbours.
Know the merits of the amateur and the complainant
keeping a log of the instances of interference.
Know the merit of conducting tests in co-operation
with the complainant in instances of interference.
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.
Know that RA and the RSGB produce information leaflets
on EMC and interference.