Table of Contents
Advertisement
4.5 External Noise and Interference Check
4.5.1 External Noise Check
Noise level can be measured (without transmission) at the echo check screen.
1) Preparation
1. Remove the 10 A fuse in the power block of the transceiver unit. See Fig. 4-1.
2. Dismount the JTX board. See Fig. 4-1.
3. Execute the echo check on menu 2.
4. Turn TVG SET off by operating the [MODE] key.
5. Set the ECHO DEPTH at 700 m by operating the [ ]
BEAM 3 BEAM 1 BEAM 2
2) Check at mooring
1. Adjust the ECHO SHIFT RANGE by the [
when the color of echograms change from blue to black.
2. This vaiue should be 7 or higher at normal noise level. If the value is less than 7,
noise is excessive.
TVG SET
0 m
OFF
ECHO SHIFT
RANGE: 1
TX POWER
BEAM 1: 110
BEAM 2: 110
BEAM 3: 110
700 m
+ B VLT: 255
Fig.4-10
] knob, noting the ECHO SHIFT RANGE
4-15
These values are
indicated without
JTX board.
Advertisement
Table of Contents
