Furuno FSV-75, Operator'S Manual

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3. VERTICAL SLANT MODE
3-10
4. Left-click the S or T button to select the desired setting.
The setting range is [0] to [9]. The higher the setting, the greater the TX power.
5. Select [Quit], then left-click.
6. Close the menu.
3.8 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.
3.8.1 How to identify the noise source
To eliminate noise effectively, you should first identify the noise source as follows:
1. Stop transmission; select [OFF] at main menu
→
[8 Test]
→
[9 Transmission].
Turn on the power of all on-board equipment one by one while observing the pic-
ture. If noise appears on the sonar display, that equipment is emitting noise.
Check the offending equipment's grounding 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:
3.8.2 Change the TX interval
When other sonars nearby are operating 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. Open the menu.
2. Select [1 TX/RX Setting], then left-click.
3. Select [1 TX Interval], then left-click.
4. Left-click the
S or T button to select the desired setting.
• [1] to [9]: the smaller the setting, the shorter the interval.
• [Random1] to [Random4]: changes the interval with each pulse, reducing the
possibility of interference. A higher setting increases the available intervals
used for the random change.
• [External Synch]: Matches the intervals with the signal input from an external
source.
TX interval high TX interval lowered
Interference