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FCC PART 15, SUBPART C, SEC. 15.247 - DIRECT SEQUENCE SPREAD SPECTRUM TRANSMITTERS
PCMCIA Wireless LAN Card, Model WL-211F
8.2.
METHOD OF MEASUREMENTS - AC MAINS CONDUCTED EMISSIONS
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AC Mains conducted emissions measurements were performed in accordance with the standard against appropriate
limits for each detector function.
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The test was performed in the shielded room, 16'(L) by 16'(W) by 12'(H).
•
The test was performed were made over the frequency range from 450 kHz to 30 MHz to determine the line-to-
ground radio noise voltage which was conducted from the EUT power-input terminals that were directly connected to
a public power network.
•
The EUT normally received power from another device that connects to the public utility ac power lines,
measurements would be made on that device with the EUT in operation to ensure that the device continues to comply
with the appropriate limits while providing the EUT with power.
•
If the EUT operates only from internal or dedicated batteries, with no provisions for connection to the public utility
ac power lines, AC Mains conducted measurements are not required.
•
Table-top devices were placed on a platform of nominal size 1 m by 1.5m raised 80 cm above the conducting ground
plane.
•
The EUT current-carrying power lead, except the ground (safety) lead, was individually connected through a LISN to
the power source. All unused 50-Ohm connectors of the LISN was terminated in 50-ohm when not connected to the
measuring instruments.
•
The line cord of the EUT connected to one LISN which was connected to the measuring instrument. Those power
cords for the units of devices not under measurement were connected to a separate multiple ac outlet. Drawings and
photographs of typically conducted emission test setups were shown in the Test Report. Each current-carrying
conductor of the EUT shall be individually tested.
•
The EUT was normally operated with a ground (safety) connection, the EUT was connected to the ground at the
LISN through a conductor provided in the lead from the ac power mains to the LISN.
•
The excess length of the power cord was folded back and forth in an 8-shape on a wooden strip with a vertical prong
located on the top of the LISN case.
•
The EUT was set-up in its typical configuration and operated in its various modes as described in this test report.
•
A preliminary scan was made by using spectrum analyzer system with the detector function set to PEAK mode (9
KHz RBW, VBW > RBW), frequency span 450 kHz to 30 MHz.
•
The maximum conducted emission for a given mode of operation was found by using the following step-by-step
procedure:
Step1.
Monitor the frequency range of interest at a fixed EUT azimuth.
Step2.
Manipulate the system cables and peripheral devices to produce highest amplitude signal relative to the
limit. Note the amplitude and frequency of the suspect signal.
Step3.
The effects of various modes of operation is examined. This is done by varying equipment operation
modes as step 2 is being performed.
Step4.
After completing step 1 through 3, record EUT and peripheral device configuration, mode of operation,
cable configuration, signal levels and frequencies for final test.
•
Each highest signal level at the maximized test configuration was zoomed in a small frequency span on the spectrum
analyzer's display (the manipulation of cables and peripheral devices and EUT operation modes might have to be
repeated to obtain the highest signal level with the spectrum analyzer set to PEAK detector mode 10 KHz RBW and
VBW > RBW). The spectrum analyzer was then set to CISPR QUASI-PEAK detector mode (9 KHz RBW, 1 MHz
VBW) and AVERAGE detector mode (10 kHz RBW, 1 Hz VBW). The final highest RF signal levels and
frequencies were record.
ULTRATECH GROUP OF LABS
3000 Bristol Circle, Oakville, Ontario, Canada L6H 6G4
Tel. #: 905-829-1570, Fax. #: 905-829-8050, Email: vhk.ultratech@sympatico.ca, Website: http://www.ultratech-labs.com
•
Assessed by ITI (UK) Competent Body, NVLAP (USA) Accreditation Body & ACA/AUSTEL (Australia)
•
Accredited by Industry Canada (Canada) under ACC-LAB (Europe/Canada MRA)
•
Recognized/Listed by FCC (USA )
•
All test results contained in this engineering test report are traceable to National Institute of Standards and Technology (NIST)
Page 66
FCC ID: MXF-WL211F
File #: GTT-013FTX
March 17, 2000
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