vsat dish
Whether antenna can operate normally is directly related to communication line unblocked or not. Therefore, it is very important that users should perform ongoing maintenance and handle the accidental trouble immediately for antenna.
Case 1
Phenomenon: For 13m antenna, antenna elevation displays no change observed from ACU, but antenna elevation motor operates normally.
Settlement: Measure elevation motor power supply which displays normal by multi-meter. And then open the case of elevation motor belt after elevation motor is cut off. You will find that belt is slipping, change it into a new one. Thus antenna elevation can operate normally.
Case 2
Phenomenon: For 16m antenna, the level of antenna tracking receiver falls suddenly by a large margin in more rain season. Feed membrane is damaged, observed directly ahead of antenna.
Settlement: Make antenna point to the sky and have feed barrel waterproof. Disassemble feed waveguide and exhaust the water inside it after the rain stops. Dry the inside of waveguide by heat air. Change membrane and open waveguide aerator.
Case 3
Phenomenon: For 16 antenna, antenna tracking deviates from satellite many times in summer when it is windy outside. However, antenna system device doesn’t have hardware trouble.
Settlement: Have a test on antenna tracking precision which is normal. Then check receiving beacon level value of tracking receiver in one year. You can find that level in winter is higher 2dB than level in summer and in winter antenna tracking doesn’t deviate from satellite. Antenna deviation occurs because it is windy outside. Check the environment directly ahead of antenna. There are two trees with lush leaves in the due front of antenna. Because leaves can absorb wave signal, antenna receiving level falls 2dB in comparison with that in winter. Antenna receiving level gets more unstable because the tree shakes violently in windy summer. At the time, receiving level of ACU varies 2dB; it indicates that you should reboot antenna tracking. Due to tree’s shaking, antenna receiving level is unstable. Thus ACU will restart satellite tracking status, which causes that the logical judgment of ACU has the problem. So antenna can not track satellite correctly. After cutting the tops of the tree, antenna tracking satellite has never deviated up to now.
Case 4
Phenomenon: For 16m antenna, when antenna polarization is electrically tuned, polarization gear often falls off.
Settlement: Polarization gear which is fixed by a half of circular steel mat provides enough lateral force so that polarization gear doesn’t slide when rotating. When antenna elevation angle is higher, longitudinal force is partially cancelled out by gravity. So polarization gear falls off when adjusting polarization. Drill a screw hole on the polarization gear and fix polarization gear on the polarization axis by screw. Thereby the trouble is eliminated.
Case 5
Phenomenon: For 16m antenna, ACU displays limit warning on azimuth antenna.
Settlement: In fact, the antenna isn’t limited after check. Limit-switch doesn’t have 12V DC voltage to send back after measuring the control case. Open antenna limit-switch and find that it is burnt-in, and renew it. Azimuth limit warning on ACU disappears after antenna limit-switch is renewed.
Case 6
Phenomenon: For 13m antenna, ACU cannot control antenna. The local panel can control rotation of antenna azimuth, but it cannot control rotation of antenna elevation.
Settlement: Elevation 3-phase power is normal after check. 3-phase protective tube is normal after measurement. Measure AC contactor’s control voltage, when driving antenna elevation, AC contactor doesn’t have control voltage input. Check the diagram of circuit theory and find control contactor’s relay which is to control voltage. After check, the relay doesn’t have reaction when there is a need of relay closing. After renewing the relay, the local control antenna elevation is normal and ACU control antenna elevation is also normal. Thus trouble is removed.
Case7
Phenomenon: For 13m antenna, ACU displays trouble on OCU-CCU Link Down. ACU cannot control antenna to rotate.
Settlement: Reboot CCU and observe whether trouble is removed on ACU. If trouble cannot be removed, reset interface board which communicates with OCU. If resetting is inoperative, change it into back-up interface board.
Case 8
Phenomenon: There is too much snow on horn mouth, which affects antenna gain.
Settlement: Under this condition, clear snow on antenna in time to ensure that antenna can operate normally.
Case 9
Phenomenon: There is abnormalities (sound, heating, insufficiency of lubrication) when antenna rotates.
Settlement: Find abnormality and add low temperature extreme grease or change damaged parts.
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