Sea Tel 9797A-27, Installation And Operation Manual

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9797A-27 C-Band TXRX Setup
5-3
Figure 5-2 Antenna stopped before the Bow
Figure 5-3 Antenna stops past the Bow
approximately how far you will have to drive). Refer, in general terms, to the Optimizing Targeting
procedure.
If the antenna stopped before it got to the bow-line; When you initially target a satellite, the
antenna will also stop prior to the satellite
position, so you that will have to drive the
Azimuth of the antenna UP to actually
find the satellite. Using the same basic
procedure as in the Optimizing Targeting
paragraph, target the satellite and record
the “Calculated” Azimuth position that the
antenna was driven to. Drive UP until you
find the satellite, positively identify that
you are on
the satellite you targeted and
allow tracking to peak the antenna
position. Record the “Peak” Azimuth
position. Subtract the “Peak” position
from the “Calculated” position to
determine the number of degrees of AZ
TRIM that would be required.
Example: In this new installation, I target
my desired satellite and record the
Calculated Azimuth to be 180.5. I drive
UP and finally find my desired satellite at
a Peak Azimuth of 227.0 degrees. I subtract Peak from Calculated and difference to be –46.5
degrees, therefore the actual Relative position that needs to be preset into the counter when the
antenna is at the Home Flag is 313.5. HFO = ((360-46.5) / 360)) x 255 = (313.5 / 360) x 255 =
0.87 x 255 = 222.06 which I round down to 222.
If the antenna went past the bow-line; When you initially target a satellite, the antenna will also go
past the satellite position, so that you will have to drive the Azimuth of the antenna DOWN to
actually find the satellite. Using the same
basic procedure as in the Optimizing
Targeting paragraph, target the satellite
and record the “Calculated” Azimuth
position that the antenna was driven to.
Drive DOWN until you find the satellite,
positively identify that you are on
the
satellite you targeted and allow tracking
to peak the antenna position. Record the
“Peak” Azimuth position. Subtract the
“Peak” position from the “Calculated”
position to determine the number of
degrees of AZ TRIM that would be
required. . Refer to the calculations
above to determine the HFO you should
use for this antenna.
Example: In this new installation, I target
my desired satellite and record the
Calculated Azimuth to be 180.0. I drive
DOWN and finally find my desired
satellite at a Peak Azimuth of 90.0 degrees. I subtract Peak from Calculated and difference to be
+90.0 degrees, therefore the actual Relative position that needs to be preset into the counter
when the antenna is at the Home Flag is 90.0. HFO = ((90.0) / 360)) x 255 = 0.25 x 255 = 63.75
which I round up to 64.
5.4.2. To Enter the HFO value: