OIN3890BX1846S35Pentium II Computer

NATIONAL CERTIFICATION LABORATORY 8370 Court Avenue, Suite B-1 Ellicott City MD 21043 (410) 461-5548 FCC REPORT OF RADIO INTERFERENCE for Lyrex Microsystems 6059 Corporal Lane Boise, ID 83704 FCC ID: OIN3890BX1846S35 April 14, 1999 TABLE OF CONTENTS Application Form 731 FCC Label Drawing and Location 1.0 Introduction 1.1 Summary 2.0 Description of Equipment Under Test (EUT) 2.1 EMI Countermeasures 3.0 Test Program 4.0 Test Configuration 5.0 Conducted Emissions Scheme 6.0 Radiated Emissions Scheme TABLES Table 1.Support Equipment Table 2.Interface Cables Table 3. Measurement Equipment EXHIBITS Exhibit 1.EUT Photographs Exhibit 2. Schematic Diagram Exhibit 3. User Manual NCL PROJ.# LYREX-0474 FCC ID #: OIN3890BX1846S35 1 1.0 Introduction This report has been prepared on behalf of Lyrex Microsystems, to support the attached Application for Certification of a Part 15 Class B Digital Device. The Equipment Under Test was the BX ATX Pentium II Tower Computer. Radio-Noise Emissions tests were performed according to the ANSI C63.4- 1992, Chapter 11 titled "Measurement of Information Technology Equipment". The measuring equipment conforms to ANSI C63.2 Specifications for Electromagnetic Noise and Field Strength Instrumentation. Testing was performed at National Certification Laboratory in Ellicott City, MD. Site description and site attenuation data have been placed on file with the FCC's Sampling and Measurements Branch. FCC acceptance was granted on May 26, 1993. 1.1 Summary The Lyrex Microsystems BX ATX Pentium II Tower Computer complies with the limits for a Class B Digital Device. 2.0 Description of Equipment Under Test (EUT) The EUT Features: MICRO-PROCESSORS CLOCK SPEEDS Pentium-II 450 66/100 MHz Celeron 300 66/100 MHz OTHERS OSCILLATORS 2 AT Slots Motherboard: 5 PCI Slots AGP Video Slot 14.318 MHz 3 DIMMS 32.768 KHz 2 Serial Ports FCC ID #: OIN3890BX1846S35 2 1 Parallel Port FDD/IDE Ctrls. USB Ports 2.1 EMI Countermeasures The following modifications were made to the EUT, by the project engineer to assure compliance to Class B specifications: 1. None 3.0 Test Program The EUT was tested with an AGP video card. A program was written to send a continuous stream of "H's" to the video, serial, and parallel ports of the computer. 66 and 100 MHz clock-based CPUs were tested. Worst case emissions are recorded in the data tables. BASIC program used: 10 FOR N=1 TO 35 15 FOR M=1 TO 80 20 PRINT "h";: 25 NEXT M 30 NEXT N 40 OPEN "COM1:1200,E,7,1,CSO,DSO" FOR OUTPUT AS #1 50 OPEN "COM2:1200,E,7,1,CSO,DSO" FOR OUTPUT AS #2 52 FOR I=1 TO 160 54 PRINT #1,"H";: 56 PRINT #2,"H";: 58 NEXT I 60 FOR J=1 TO 80 65 LPRINT "H";: 70 NEXT J 75 CLOSE FCC ID #: OIN3890BX1846S35 3 80 GOTO 10 4.0 Test Configuration The computer system and support equipment were setup on the test table in a manner which follows the general guidelines of ANSI C63.4, Section 6.2.1. The support equipment consisted of a keyboard, video monitor, printer, mouse and modem as prescribed in Section 11.2 (ANSI C63.4). The computer was centered on the table with it's backplane flush with the rear of the table. The video monitor was placed 10 cm on the right side of the computer with its back flush with the rear of the table. The modem was placed 10 cm from the right side of the monitor, while the printer was set on the opposite side of the EUT, also 10 cm away. The keyboard was placed in front of the monitor, and flush with the front of the test table. All other equipment such as mice were placed in the front of the table on either side of the keyboard, maintaining 10 cm spacings. Two unterminated USB serial cables were connected to the EUT, and placed on either side of the computer to maximize emissions. Serial, video and parallel I/O cables were draped over the back edge of the table, and the keyboard and mouse cables were placed on top of the table. Cables were more than 40 cm from the ground plane during radiated and conducted tests. The video monitor was powered from the table’s 120VAC outlet which produced worst-case emissions. Photographs and interconnection diagrams are provided in Exhibit 1. 5.0 Conducted Emissions Scheme The EUT is placed on an 80 cm high 1 X 1.5 m non-conductive table. Power to the CPU is provided through a Solar Corporation 50 Ω/50 μH Line Impedance Stabilization Network bonded to a 2.2 X 2 meter horizontal ground plane, and a 2.2 X 2 meter vertical ground plane. FCC ID #: OIN3890BX1846S35 4 The LISN has its AC input supplied from a filtered AC power source. A separate LISN provides AC power to the peripheral equipment. I/O cables are moved about to obtain maximum emissions. The 50 Ω output of the LISN is connected to the input of the spectrum analyzer and emissions in the frequency range of 450 kHz to 30 MHz are searched. The detector function is set to quasi- peak and the resolution bandwidth is set at 9 kHz, with all post-detector filtering no less than 10 times the resolution bandwidth for final measurements. All emissions within 20 dB of the limit are recorded in the data tables. 6.0 Radiated Emissions Scheme The EUT was initially scanned in the frequency range 30 to 2000 MHz indoors, at a distance of 1 meter to determine its emissions profile. The EUT was then placed on an 80 cm high 1 X 1.5 meter non-conductive motorized turntable for radiated testing on the 3- meter open area test site. The emissions from the EUT are measured continuously at every azimuth by rotating the turntable. Biconical, horn, and log periodic broadband antennas are mounted on an antenna mast to determine the height of maximum emissions. The height of the antenna is varied between 1 and 4 meters. Cables are varied in position to produce maximum emissions. Both the horizontal and vertical field components are measured. Measurements from 30 -1000 MHz: The output from the antenna is connected to the input of the spectrum analyzer. The detector function is set to quasi-peak. The resolution bandwidth of the spectrum analyzer system is set at 120 …

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RADIATED TEST CONFIGURATION CONDUCTED TEST CONFIGURATION