3. SETTING AND ADJUSTMENT

3.3Heading Alignment

You have mounted the antenna unit facing straight ahead in the direction of the bow. Therefore, a small but conspicuous target dead ahead visually should appear on the heading line (zero degrees).

In practice, you will probably observe some small bearing error on the display because of the difficulty in achieving accurate initial positioning of the antenna unit. The following adjustment will compensate for this error.

Correct bearing

α

relative to heading

 

α Target

Antenna mounted error to port (HDG SW advance)

340

350

000

010

020

 

330

 

 

 

030

 

320

 

 

 

040

 

310

 

 

 

050

 

300

 

 

 

060

 

290

 

 

 

070

 

280

 

 

 

080

 

270

 

 

 

090

Apparent

260

 

 

 

100

250

 

 

 

110

position

 

 

 

 

 

240

 

 

 

120

of target

 

 

 

 

230

 

 

 

130

220

 

 

 

140

 

210

 

 

 

150

 

200

190

180

170

160

 

Picture appears deviated clockwise.

Apparent position

β

of target

 

β

Target

340

350

000

010

020

 

330

 

 

 

030

 

 

 

320

 

 

 

040

 

 

 

310

 

 

 

050

 

 

 

300

 

 

 

060

 

 

 

290

 

 

 

070

 

 

 

280

 

 

 

080

 

 

 

270

 

 

 

090

Correct

 

 

260

 

 

 

100

 

 

250

 

 

 

110

bearing

 

 

240

 

 

 

130

relative to

 

 

230

 

 

 

 

 

 

 

 

 

120

heading

 

 

210

 

 

 

150

 

 

220

 

 

 

140

 

 

 

200

190

180

170

160

 

Antenna mounted error

Picture appears

to starboard (HDG

deviated counterclockwise.

SW delayed)

 

Heading alignment

1.Select a stationary target echo at a range between 0.125 and 0.25 nm, preferably near the heading line.

2.Operate the EBL control to bisect the target echo.

3.Read the target bearing.

4.Measure the bearing of the stationary target on the navigation chart and calculate the difference between actual bearing and apparent bearing on the radar screen.

5.Press the [MENU] key to show the main menu.

6.While pressing and holding down the [HL OFF] key, press the [MENU] key five times.

3-3

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Furuno 2137S-BB, 2837S installation manual Heading Alignment, Heading alignment