ON BEAT RUMBLE (serv.man4) - JBL Audio EMC - CB Certificate (repair manual). Page 45

Report No.: EM201200813-4

                       

Application No.:

ZJ00024740

                  

Page 45 of 53

 

 

 

Frequency range  

30 MHz to 1 GHz  

-57 dBm  

above 1 GHz to 12,75 GHz  

-47 dBm  

EIRP emission test method as below  

1.  The EUT shall operate on receive mode. And Interface cables, loads, and devices should be 

connected to at least one of each type of the interface ports of the EUT and, where practical, 
each cable shall be terminated in a device typical for its actual use. EUT shall be placed at the 
1.5m support on the turntable. 

2.  The test antenna at a horizontal distance of 3 m .It shall be raised and lowered from 1m to 4m 

until a maximum signal level is detected by the measuring receiver. Then the turntable should 
be rotated through 360° in the horizontal plane, until the maximum signal level is detected by 
the measuring receiver. in both the vertical and the horizontal polarization. Record the reading 
level, antenna position, polarization and turntable position. 

3.  Remove the EUT and replace it with a substitution antenna (the antenna should be 

half-wavelength for each frequency involved). The center of the substitution antenna should be 
approximately at the same location as the center of the transmitter. For frequencies of 80 MHz 
and above, the dipoles should have theirarm lengths set for resonance at the frequency of test. 
Below 80 MHz, shortened arm lengths are recommended. For measurements above 1 000 MHz, 
a waveguide horn is recommended. The centre of this antenna should coincide with either the 
phase centre or volume centre. 

4.  Feed the substitution antenna at the EUT end with a signal generator connected to the antenna 

by a cable. With the antennas at both ends vertically polarized, and with the signal generator 
tuned to a particular test frequency, raise and lower the test antenna to obtain a maximum 
reading at the spectrum analyzer. Adjust the level of the signal generator output until the 
previously recorded maximum reading for this set of conditions is obtained. This should be 
done carefully repeating the adjustment of the test antenna and generator output. 

EIRP(dBm) = Pg(dBm) – cable loss (dB) + antenna gain (dBd) 
where: 
Pg is the generator output power into the substitution antenna. 
 
Pre-test the 3 modulation to find 8DPSK is worse case, so only record 8DPSK test data.