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DATE
DOCUMENT NAME
DOCUMENT #
PAGE
May 21, 2004
Harman Multimedia JBL OnStage EMC Test Report
2004 050310 EMC
15 of 80
4.3. Configuration and Methods of Measurements for Radiated Emissions
This test measures the levels emanating from the EUT, thus evaluating the potential for the EUT to cause radio
frequency interference to other electronic devices. Testing was performed in accordance with the test
standard(s) referenced in the test summary section of this report. The Equipment Under Test (EUT) was
configured based upon the requirements of the applicable test standard. Initially, the primary emission
frequencies are identified inside a shielded chamber by positioning a broadband receive antenna one meter
from the EUT. Next, the EUT and associated system are placed on a turntable on a ten-meter open area test site
(OATS) with known attenuation characteristics and all significant radiated emissions are recorded. To ensure
that the maximum emission at each discrete frequency of interest is observed, the receive antenna is varied in
height from one to four meters and rotated to produce horizontal and vertical polarities while the turntable is
rotated to determine the worst emitting configuration. The numerical results are included herein to demonstrate
compliance. The numerical results of the test are included herein to demonstrate compliance.
The numerical results that are applied to the emissions limits are arrived at by the following method:
Example: A=RR+CL+AF
A = Amplitude dBuV/M
RR = Receiver Reading dBuV
CL = cable loss dB
AF = antenna factor dBm-1
Example Frequency = 110MHz
18.5 dBuV (spectrum analyzer reading)
+3.0 dB (cable loss @ frequency)
21.5 dBuV
+15.4 dBm-1 (antenna factor @ frequency)
36.9 dBuV/M Final adjusted value
The final adjusted value is then compared to the appropriate emission limit to determine compliance.
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