Furuno 1833C, 1933C, 1943C, 1823C, GD-1900C, 1953C Timing Adjust, Antenna tuning, Tuning setup menu

Antenna tuning

Initialize the tuning as follows.

1.Transmit the radar.

2.Open the RADAR SETUP menu, and then select TUNING by the trackball or [ENTER] knob.

3.Press the EDIT soft key or [ENTER] knob to show the setting window.

TUNING

ON

OFF

Tuning setup menu

4.Select ON.

5.Press the [ENTER] knob or ENTER soft key to start the auto tuning.

6.After the adjustment is completed, the message of “NOW TUNING” disappears.

7.Return to the menu display automatically.

3.3.3TIMING ADJUST

This adjustment ensures proper radar performance, especially on short ranges. The radar measures the time required for a transmitted echo to travel to the target and return to the source. The received echo appears on the display based on this time. Thus, at the instant the transmitter is fired, the sweep should start from the center of the display (sometimes called sweep origin.)

A trigger pulse generated in the display unit goes to the antenna unit through the signal cable to trigger the transmitter (magnetron). The time taken by the signal to travel up to the antenna unit varies, depending largely on the length of signal cable. During this period the display unit should wait before starting the sweep. When the display unit is not adjusted correctly, the echoes from a straight local object (for example, a harbor wall or straight pier) will not appear with straight edges – namely, they will be seen as “pushed out” or “pulled in” near the picture center. The range of objects will also be incorrectly shown.

(1) Target	(2) Correct	(3) Target pushed
pulled		outward

Examples of improper and correct sweep timing

1.Transmit on the shortest range and confirm that gain and A/C SEA are properly adjusted.

2.Visually select a target which forms straight line (harbor wall, straight piers).

3.Open the RADAR SETUP menu and select TIMING ADJUST.

4.Press the EDIT key or [ENTER] key to show the setting window.

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