Furuno FSV25S, Operator'S Manual

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2. HORIZONTAL MODE
2-13
5. Click S or T to change the setting. The setting range is 0 to 9. The higher the
setting the greater the TX power.
6. Click [Quit] on the setting box to close the box.
7. Long-push the
MENU/ESC key to close all menus.
2.9 How to Reject Sonar Interference and Noise
While observing the sonar picture, you may encounter occasional or intermittent noise
and interference. These are mostly caused by on-board electronic equipment, engine
or propeller noise, or electrical noise from other sonars being operated nearby.
2.9.1 How to identify the noise source
To eliminate noise effectively, you should first identify the noise source as follows:
1. On the [Test] menu, turn [TX] off to stop transmitting. Turn on the power of all on-
board equipment one by one while observing the picture. If noise appears on the
sonar display, that equipment is emitting noise. Check the offending equipment's
ground and installation.
2. Run the boat at various speeds to check if the noise is speed dependent.
If neither of the above two steps has effect on the picture, adjust one of the following:
2.9.2 Change TX interval
When other sonars nearby are oper-
ating the same transmission interval
as that of own ship's sonar, rings of
interference appears on the display.
To remove the rings from the screen,
do the following:
1. Press the MENU/ESC key to
show the main menu.
2. Click [TX/RX Setting].
3. Press the
H/V/S key to select the
[H1] tab.
4. Click [TX Interval].
5. Click
S
or
T
to change the setting. [External Sync] synchronizes transmission
with the external input signal. [Random1] - [Random4] change the interval with
each transmission, to prevent reception of interference in the same timing. The
larger the number the greater the average interval.
6. Click [Quit] on the setting box to close the box.
7. Long-push the
MENU/ESC key to close all menus.
Interference
Tx interval high Tx interval lowered