4.Press or to adjust TVG distance, considering sea conditions. The larger the figure the greater the distance at which the TVG works.

TVG

 

 

 

 

 

 

 

 

 

 

 

. . . .

10.0

Distance

0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

Setting

 

 

 

 

 

 

 

 

 

 

 

 

 

Meters

3

8

20

40

60

100

130

160

200

250

320

. . . .

1000

Feet

10

30

70

130

210

330

410

520

660

820

1040

 

3280

Passi/braza

2

5

10

20

40

60

80

100

120

150

180

 

600

Hiro

2

5

10

20

40

60

80

100

130

170

210

. . . .

660

5.Press or to close the dialog box and return to the VERT menu.

6.To suppress reflections by the sea surface or plankton, select TVG LEVEL and press .

7.Press or to adjust TVG LEVEL, considering sea conditions. The larger the figure the less the gain over distance.

8.Press the [MENU] key to register your selection and close the menu.

Wrong

Correct

Level too high

Distance too high

Figure 3-14 Examples of proper and improper TVG

3.11.2 Suppressing noise and interference

You may encounter occasional or intermittent noise and interference as shown below. This is mostly caused by electrical equipment, engine, propeller noise from own ship, or noise from other sonars being operated nearby. If interference appears, turn on the interference rejector in the COM1 menu to suppress it.

Interference rejector ON

Interference (In this display, interference shows itself every 6˚.)

Figure 3-15 Appearance of interference

3-11

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Furuno CH-250 manual Suppressing noise and interference, Examples of proper and improper TVG