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4.1. Test  Equipments 

Item 

Equipment 

Manufacturer Model No.

Serial No. 

Last Cal.  Cal. Interval

1.    EMC Analyzer 

Agilent 

E7405A 

MY42000131 May 11, 07 

1 Year 

2.  

Test Receiver 

Rohde & 

Schwarz 

ESVS10 

834468/011  May 11, 07 

1 Year 

3.   Amplifier 

Agilent 

8447D  2944A10684

Jul.14, 

07  1/2

 

Year 

4.    Bilog Antenna 

Schaffner 

CBL6111C

2768 

Feb.22, 07 

1 Year 

RF Cable 

MIYAZAKI

8D-FB 

10m Chamber No.1

Feb.07, 07 

1/2 Year 

6.   RF 

Cable 

MIYAZAKI

8D-FB 

10m Chamber No.2

Feb.07, 07 

1/2 Year 

7.   RF 

Cable 

MIYAZAKI

8D-FB 

10m Chamber No.3

Feb.07, 07 

1/2 Year 

8.   RF 

Cable 

MIYAZAKI

8D-FB 

10m Chamber No.4

Feb.07, 07 

1/2 Year 

9.    Coaxial Switch 

Anritsu 

MP59B 

M74389 

Feb.07, 07 

1/2 Year 

4.2.  Block Diagram of Test Setup 

4.2.1.  Block Diagram of connection between EUT and simulators 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

PC  

AC Mains

 

Keyboard 

Mouse 

EUT 

AC Mains 

Printer

a: Audio Cable 
b: USB Cable 
 : Core 

a

Adaptor

Modem

Adaptor

Monitor

Headphone 

b

4.2.2.  In Anechoic Chamber Test Setup Diagram 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 

4.3. Test  Standard 

EN55022: 1998+A1:2000+A2: 2003 

4.4. Radiated Emission Limit 

All emanations from a Class B computing devices or system, including any network of 
conductors and apparatus connected thereto, shall not exceed the level of field strengths 
specified below: 

FREQUENCY 

(MHz) 

DISTANCE 

(Meters) 

FIELD STRENGTHS LIMITS 

(dB

μV/m) 

30 ~ 230 

10 

30 

230 ~ 1000 

10 

37 

Note: 

(1)  Emission level = Antenna Factor + Cable Loss + Reading 

  (2)  The lower limit shall apply at the transition frequencies. 

 

(3)  Distance refers to the distance in meters between the test antenna and the       

closed point of any part of the EUT. 

4.5. EUT Configuration on Test 

The EN55022 Class B regulations test method must be used to find the maximum 
emission during Radiated Emission test.   

The configuration of EUT is same as used in Conducted Emission test. Please refer to 
Section 3.5. 

4.6. Operating Condition of EUT 

4.6.1.  Setup the EUT and the simulators as shown on Section 4.2. 

4.6.2.  Turn on the power of all equipments. 

4.6.3.  Let the EUT work in test mode (Data Transmitting) and test it. 

ANTENNA TOWER

ANTENNA ELEVATION VARIES FROM 1 TO 4 METERS 

GROUND PLANE

10 METERS 

TURN TABLE 

0.8 METER

EUT and   
Support System 

 

4.7. Test  Procedure 

The EUT was placed on a non-metallic table, 80 cm above the ground plane inside a

 

semi-anechoic chamber. An antenna was located 10m from the EUT on an adjustable 
mast. A pre-scan was first performed in order to find prominent radiated emissions. For 
final emissions measurements at each frequency of interest, the EUT were rotated and the 
antenna height was varied between 1m and 4m in order to maximize the emission. 
Measurements in both horizontal and vertical polarities were made and the data was 
recorded. In order to find the maximum emission, the relative positions of equipments 
and all of the interface cables were changed according to EN 55022 Class B on Radiated 
Disturbance test. 
 
The bandwidth setting on the test receiver (R&S TEST RECEIVER ESVS10) is 120 kHz. 
 
All the test results and all the scanning waveform are listed in Section 4.8. 

4.8. Radiated Disturbance Test Results 

PASS. (All emissions not reported below are too low against the prescribed limits.) 
 

The EUT with the following test modes was tested and all the test results are listed in next 
pages. 

 

EUT: Computer Speaker System        Model No. : jbl on stage lll 
 
Test Date: Jul.23, 2007    Temperature: 24℃    Humidity: 56% 

The details of test models are as follows： 

Reference Test Data 

No. 

No. Test 

Mode 

Power Adaptor 

Horizontal 

Vertical

1. 

DSA-20R-12 FEU 120180 

#14 

#13 

2. 

Data Transmitting

KSAD1200150W1EU #11 #12