Sea Tel COASTAL 18 Installation And Operation Manual Download

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Coastal 18 Ku-Band TVRO

Setup

5-9

Figure 5-2 LNB rotation during polarization

adjustment

but will

NOT

rotate the LNB.

The antenna reports that it is tracking a good signal by displaying a steady (ON) TRACKING LED. If you
determine that the satellite signal is not the desired satellite, press the NEXT key to search for the NEXT
satellite signal. Continue repeating this procedure until the correct satellite is found. Once the correct
satellite has been found, allow the antenna to track for 4-6 minutes to update the satellite position
information.

5.3.1. Optimizing the polarization while on the desired satellite

This adjustment should be done while the boat is at the pier and antenna is tracking the desired satellite.
When the boat is travelling to a different
geographic area the polarization may need
to be re-optimized if performance appears
to be degrading.

Select the “Signal Strength” display of the
satellite receiver (refer to the satellite
receiver manual).  While monitoring the
receivers’ signal strength, adjust
polarization up or down in one (or two)
degree increments, then observe the
receivers’ signal strength for 10-15
seconds to evaluate the change. If an
improvement is noted, continue small
adjustments in the same direction until the
highest signal strength is obtained.  If the
adjustment causes a decrease, adjust
polarization in the opposite direction to
increase the signal strength.  When the
polarization of the antenna is optimum, tighten the set screws and re-install the radome top.

5.3.2. Setting polarization for a different satellite (changing satellites)

When changing from one satellite to another you may need to adjust the polarization of the LNB to be
able to acquire the satellite you want to switch to. This will only be required if the difference in
polarization angle of the two satellites is greater than ten degrees.

Assure that you have optimized the polarization for the satellite you are presently on using the
procedure in 2.4.1.

Compare the longitude of the satellite you are presently on to the longitude of the satellite you
will be switching to. Note the amount & direction of the difference in longitude position of the
two satellites. Adjust the polarization 10 degrees for each 10 degrees of longitude difference
between the two satellites. If the satellite you are switching to is further East from the present
satellite you will need to adjust polarization DOWN the appropriate number of degrees. If the
satellite you are switching to is West from the present satellite you will need to adjust
polarization UP the appropriate number of degrees. Examples:

Presently optimized on Astra 1 at 19.2E and want to switch to Hotbird at 13.0E.
Difference is less than 10 degrees, so no adjustment is necessary before searching for
the next satellite (step 4).

Presently optimized on Astra 1 at 19.2E and want to switch to Astra 2 at 28.2E.
Difference is about 10 degrees East. You need to rotate the LNB (POL DOWN) 10
degrees and then search for the next satellite (steps 3 & 4).

Presently optimized on Astra 1 at 19.2E and want to switch to Thor 1 at 0.8W. Difference
is about 20 degrees West. You need to rotate the LNB (POL UP) 20 degrees and then
search for the next satellite (steps 3 & 4).