3. ADJUSTMENT
3.6 Sweep Timing
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) Correct | (2) Target pushed | (3) Target pushed |
| inward | outward |
Figure 3-8 Examples of improper and correct sweep timings
1.Display the Installation Setup 2 menu and select Adjust Sweep Timing by pressing omnipad.
2.Transmit the radar on the shortest range.
3.Visually select a straight echo (harbor wall, straight pier).
4.While looking at the target selected above, press omnipad at the 9 o’clock or 3 o’clock position to straighten the target.
5.Press the [ENT] key.
6.After adjustment press the [MENU] key and turn off the power to close the installation menu.