BS EN 50083-8:2002 pdf download

BS EN 50083-8:2002 pdf download.Cable networks for television signals,sound signals and interactive services一Part 8: Electromagnetic compatibility for networks.
3.1.8
carrier-to-interference ratio
minimum level difference measured at the output of an active equipment or et any other interface within the network between the wanted signal and
• intermodulation products of the wanted signal andlor unwanted signals generated due to nonIineaflties;
• harmonics generated by an unwanted signal:
• unwanted signals that have penetrated into the operating frequency range:
• unwanted signals that have been converted to the frequency range to be protected (operating frequency range)
3.1.9
headend
equipment which is connected between receiving antennas or other signal sources and the remainder of the cable network, to process the signals to be distributed
NOTE The headend may. fu example. comprise antenna aplifiers, frequency converters. conitwwrs. separators and generators.
3.1.10
system outlet
device for interconnecting a subscriber feeder and a receiver lead
3.1.11
spur network
cable network normally laid out inside buildngs to which splitters, subscriber taps or looped system outlets are connected
3.1.12
Ignition nols.
unwanted emission of electromagnetic energy, predominantly impulsive In content, arising from the
Ignition system within a vehide or device
3.1.13
buildIng p.n.tratlon loss
ability of buildings, in which networks for cbstribution of television and sound are located, to attenuate the influence of electromagnetic fields from outside the buildings or to suppress the radiation of electromagnetic fields from inside the buildings
3.1.14
disturbance level
level of an electromagnetic disturbance at a given location, which results from all contributing (interference) sources
3.1.15
degradation (of performance) (1EV 161-01-19]
undesired departure in the operational performance of any desnce, equipment or system from its intended performance
NOTE The term clegradat.on can apply to temporary or permanent falure
3.1.16
subsertbers feeder
feeder connecting a subscriber tap to a system outlet or, where the latter is not used, directly to the subscriber equipment
NOTE A subscriber feeder may inciude filters arid baks’ transformer.
NOTE Only the abbreviations used in the English version of this part ci EN 50063 a’s mentioned in this subdause The German and the French versions of this part may use other abbreviations. Rater to 3.3 ci each language versions for details.
4 Methods of measurement
These methods of measurement describe the procedures for the testing of cable networks. The purpose of the measurements is to determine:
• the level of radiation generated by cable networks and
• the immunity of cable networks to external field strengths (e.g. those radiated by other radiocommunication services and RF applications).
The measurements cover the essential parameters and enviroonienlal conditions in order to asse55:
• cases of electromagnetic incompatibility between cable networks and other electrical or electronic equipment, networks, installations or other cabled networks with respect to the intended operation of such cable networks.
During the test the cable network shall operate with normal signal leve4s at the subscriber outlets, If the stream is interactive, typical levels of the return path signals shall be maintained during the test.
NOTE Methods of measurement for ditally modulated signals are under consideration.
4.1 RadIation from cable networks
The methods descnbed hereafter are applicable to the measurement of radiation from cable networks (combination of cables, equipment and networks).
Testing of the cable networks for compliance with the relevant limits may be irstialty carried out with the terminal equipment connected. Where limits are exceeded. in*vidual sections of the network (e.g. headend, satellite receiving outdoor unit, cable network, distribution Installation beyond th€ system outlets and terminal equipment) may be tested In succession to determine beyond any doubt wt’ilch section of the network does not comply with the limits.
The nuniber of test frequencies shall be selected to give a realistic representation of the radiation pattern throughout the operating frequency range and to enable the maximum level of radiation to be recorded and the results interpreted accurately.
The field strength measurement procedure is used in order to achieve results which are sufficiently accurate and do not reqiare excessive technical effort.
The substitution measurement technique is applied to carry out more accurate measurements of the radiated disturbance power level generated by any part of the network.
If ckscussoris arise about the actual radiation from a cable network, the substitution method according to 4.1.2 has to be applied.