Sea Tel 4009-9 BROADBAND-AT-SEA, Руководство по установке

Страница: 54 / 153

4009-9 Installation Manual Setup – Home Flag Offset
9-2
Figure 9-2 Antenna stopped before the Bow
9.1.1. You Found a Large AZ TRIM value:
If Targeting has been optimized by entering a large value of AZ TRIM: First, verify that you are able to
repeatedly accurately target a desired satellite (/- 1.0 degrees). Then you can use the AZ TRIM
value to calculate the value of HFO you should use (so you can set AZ TRIM to zero). AZ Trim is entered
as the number of tenths of degrees. You will have to convert the AZ TRIM value to the nearest
whole
degree (round up or down as needed). Calculated HFO value is also rounded to the nearest whole
number.
If AZ TRIM was a
plus value: HFO = (TRIM / 360) x 255 Example: AZ TRIM was 0200 (plus 20 degrees).
HFO = (20/360) x 255 = (0.0556) x 255 = 14.16 round off to 14. Set, and Save, HFO to 014 using the “To
Enter the HFO value” procedure below.
If AZ TRIM was a
negative value: HFO = ((360-TRIM) / 360)) x 255 Example: AZ TRIM = -0450 (minus 45
degrees). HFO = ((360 – 45) / 360)) x 255 = (315 / 360) x 255 = 0.875 x 255 = 223.125 round of to 223. Set,
and Save, HFO to 223 using the “To Enter the HFO value” procedure below.
9.1.2. You Observe “Home” Pointing is LEFT of the Bow-line:
1. In this example, I observe that the
Home position is short of the bow
line.
2. I estimate that it is about 45
degrees.
3. I target my desired satellite and
record the Calculated Azimuth to be
180.5.
4. I drive UP (I estimated that I will
need to go UP about 45 degrees)
and finally find my desired satellite.
5. Turn tracking ON to let the ACU
peak the signal up. When peaked,
the Azimuth is 227.0 degrees.
6. I subtract Calculated from Peak (227
– 0180.5 = 46.5) and difference is
46.5 degrees.
7. I can calculate what the correct value for the Home position of the antenna by subtracting
(because “home” was to the left of bow) this difference of 46.5 from the bow line position 360.0.
Therefore “home” should be 313.5 Relative.
8. I now calculate the HFO = (313.5 / 360) x 255 = 0.87 x 255 = 222.06 which I round off to 222.
9. I set, and Save, HFO to 222 using the “To Enter the HFO value” procedure below. After I re-
initialize the relative position of the antenna is now calibrated.
10. If there is a small amount of error remaining, use AZ TRIM in the Optimizing Targeting
procedure to correct it.