Section 15 Maintenance & Inspection  15-16 
 
1  Turn the [VRM] dial of the operation unit to the  farthest  edge  of the performance 
monitor pattern.   
2  Check the amount of attenuation in the dialogue. 
Benchmarks for the amount of attenuation are as follows: 
Attenuation Value of Transmitter: 
At normal: -6.9 dB to +2.0 dB 
At degrading performances: -15.0 dB to -7.0 dB 
Attenuation Value of Receiver: 
At normal: -2.9 dB to +3.5 dB 
At degrading performances: -15.0 dB to -3.0 dB 
 
•  When confirming the attenuation value of the transmitter, after opening the dialogue, wait for 
one minute, and then read its value. 
•  If the attenuation value of the transmitter is -7 dB or lesser, or the receiver’s attenuation 
indicator is -3 dB or lesser, it indicates that performances of the transmitter/receiver unit are 
degrading. 
In this case, inspection by the specialized service personnel is required. Contact our dealer, the 
nearest service representative or JRC sales. 
 
   
farthest edge of the 
performance monitor pattern. 
Performance monitor pattern 
(If the performance of the receiver degrades, the 
pattern range becomes short.)