AUTHENTICS L8 (serv.man2) - JBL Audio EMC - CB Certificate (repair manual). Page 27

Report No.: EM201300650-1                         Application No.: ZJ00032008                       Page 27 of 42 
 

 

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 transmitter 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. 

5.  Repeat the step1~4 when the EUT is standby. 
6.  Where: E.I.R.P (dBm) = Pg (dBm) – cable loss (dB) + 

antenna gain (dBi). Pg is the generator output power into the 
substitution antenna 

Remark:    

Pre-scan all the rate, found that:  
11Mbps of rate is the worst case of 802.11b;  
54Mbps of rate is the worst case of 802.11g ;