Sea Tel 9711-44 KU-BAND TX/RX Installation And Operation Manual Download

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9711-44 Ku-Band TXRX

Setup – Searching

11-3

11.1.3.

No Gyro Search Pattern

If the ship does not have a gyro compass to use as a heading input to the Antenna Control Unit, you may

manually key in the actual heading of the vessel and then re-target the desired satellite, every time you need
to re-target a satellite, or configure the ACU to do a “No Gyro Search Pattern”.
You configure the ACU to use this pattern by using the following settings:

SEARCH INC

- set to the default value for the frequency band that your antenna model is currently

being used for (typically 15 counts).

SEARCH LIMIT

– leave this set to the default value.

SEARCH DELAY

– default, or any number of seconds from 1-255 that you would prefer that the

ACU wait before starting an automatic search.

SWEEP INC

– Larger antennas should have slower speeds and smaller antennas should have faster

speeds:

Larger antennas should have slower speeds set to 0047 (= 5 degrees/second) for 2.4M to

3.6M antenna systems).
Mid size antennas can be driven a little faster, set to 0063 (= 8 degrees/second) for 2M

antennas models).
Smaller antennas should have faster speeds, set to 0079 (= 18 degrees/second) for all

0.8M to 1.5M antenna models).

GYRO TYPE

– MUST be set to zero for this search pattern.

SAT REF

mode –

MUST

for this search pattern.

Target any satellite longitude value which includes even tenths digit values (ie SAT 101.0 W or SAT 101.2 W).
If the desired satellite longitude includes an odd tenths digit, you must round it up, or down, one tenth to

make the tenths digit EVEN. The Antenna Control Unit calculates the Azimuth, Elevation and Polarization

values it will use to target the antenna. However, without heading input, the ACU cannot target a “true

azimuth” position (relative to true North). It will target the antenna to the calculated elevation and a

repeatable “Start” relative azimuth position. In Series 04 antennas this relative position will be 90 degrees

away from the nearest mechanical stop. In all other antennas it will be 000 degrees relative.
Initially the antenna will go to the “Start” relative azimuth position at the calculated elevation. Then the

antenna will search up 450 degrees in azimuth, search up one Search Increment in elevation, search down

450 degrees in azimuth, search down two Search Increments in elevation, etc until Search Limit is reached.

When the end of the search pattern is reached, the ACU will retarget the antenna back to the start point

shown in the graphic below.
If the desired signal is found (AND network lock is achieved in the satellite modem) at this position, or
anywhere within the search pattern, the ACU will terminate search and go into Tracking mode. If the desired

signal is not found the ACU will wait SEARCH DELAY seconds and then begin the search pattern again. This

cycle will repeat until the desired satellite signal is found or the operator intervenes.