DOWNLOAD JBL ON STAGEII (serv.man6) Service Manual ↓ Size: 1.72 MB | Pages: 72 in PDF or view online for FREE

Nemko USA, Inc. 

Janurary 5,2006 

Harman Multimedia  OnStage UD    CE Test Report 

2006 011114 CE AUS/NZ 

 

 

1.  Test Laboratory (6 X 6 meters) 
2.  Ground Plane (15 square meters) 
3.  Vertical Conducting Wall (Grounded through Ground Plane via 10' ground rod) 
4.  AC Power for Devices  
5.  Power Line Filter, Lindgren, 120 dB, 30 amp 
6.  Artificial Mains Network (AMN) for peripheral devices 
7.  Power Distribution Box for peripheral devices 
8.  Spectrum Analyzer with Quasi-Peak Adapter 
9.  High Pass Filter 
10.  Coax input from EUT AMN to Spectrum Analyzer 
11.  AMN for EUT 
12.  EUT: Computer Speaker System and Associated System 

 

8 

7 

40 cm

9 

4 

1 

2 

3 

6 

5 

11

12 

13 

10 

Nemko USA, Inc. 

Janurary 5,2006 

Harman Multimedia  OnStage UD    CE Test Report 

2006 011114 CE AUS/NZ 

 

 

 

When performing all testing of equipment, the actual emissions of the EUT are segregated from ambient 

signals present within the laboratory or the open-field test range. Preliminary testing is performed to ensure 

that ambient signals are sufficiently low to allow for proper observation of the emissions from the EUT. 

Ambient signals within the laboratory are compared to those noted at the nearby open-field site to 

discriminate between signals produced from the EUT and ambient signals.  In the event that a significant 

emission is produced by the EUT at a frequency that is also demonstrating significant ambient signals, the 

spectrum analyzer is placed in the peak mode, the bandwidth is narrowed and the EUT's signal is centered on 

the analyzer.  The scan width is expanded to 50 kHz while monitoring the audio to ensure that only the EUT 

signal is present, the analyzer is switched to quasi-peak mode, and the level of the EUT signal is recorded. 

Nemko USA, Inc. 

Janurary 5,2006 

Harman Multimedia  OnStage UD    CE Test Report 

2006 011114 CE AUS/NZ 

 

Figure 3.   Frequency ID of Radiated Emissions Test Setup Diagram 

 

 
1.  Test Laboratory  
2.  Spectrum Analyzer with Quasi-Peak Adapter 
3.  Coax interconnect from Antenna to Spectrum Analyzer 
4.  Receive Antenna (basic relative position) 
5.  Non-Conducting table 80 cm above ground plane 
6.  Power strip for EUT and peripherals 
7.  AC power for devices 
8.  EUT: Computer Speaker System and Associated System 

 

1 

8 

1m 

2 

3 

4 

5 

6 

7 

Nemko USA, Inc. 

Janurary 5,2006 

Harman Multimedia  OnStage UD    CE Test Report 

2006 011114 CE AUS/NZ 

 

 

 
EN 55022 also specifies limits and methodology for radiated emissions testing.  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, and the 

turntable is also rotated to determine the worst emitting configuration. The numerical results of the test 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.