Terrasat IBUC 3, Operation Manual

Page: 106 / 236

7-16
|
IBUC
3
, IBUC
3 G
Operations Manual: Transmit Redundant Systems
Engineered to Endure
2. Use the modem or converter level adjust to increase and decrease the power level.
Adjust to reach a level of -24 dBm (this will result in rated power at the IBUC
3
or
IBUC
3
G
output).
3. Check that the 10 MHz reference signal is within the range of +5 dBm to -12 dBm.
Note:
The IBUC
3
and IBUC
3
G
require a 10 MHz reference signal to operate. Check
the model number of the IBUC to determine whether an external 10 MHz signal is
required.
4. Disconnect the spectrum analyzer from the coaxial cable.
Transmit RF Output Adjustment with Modem or Converter
To adjust the power level of the IBUC transmitter output:
1. Ensure that the power level at the input of the IBUC does not exceed -30 dBm at
startup.
Note:
For more information about how to set the Tx frequency, see Setting the Tx Fre -
quency (L-band) on page 4 - 4 .
2. Ensure that the 10 MHz reference signal (either internal or external) is present
3. Apply power to the IBUCs.
4. Enable the Tx signals in the modem or converter and the IBUCs.
5. With a satellite modem: Adjust the RF output to the designated power level
(provided by the satellite network operations center or its engineering staff) with
the L-band output (modem) level adjust. Do this for both systems (A: side and B:
side). Equalize the gains by using the gain setting control of the IBUCs.
Note:
There are differences between the units and the autocloning feature does not trans -
fer the attenuator settings from the Master (or online) unit to the Slave (or standby)
unit.
6. Under the guidance of the network operations center, fine-adjust the transmit
power for the desired down-link margin at the receiving station by adjusting the Tx
L-band output level adjust (modem or converter output).
Note:
For more information about configuring the IBUCs, see Chapter 4, Operations . For
more information about configuring and operating in redundant mode, see the
Redundancy Configuration Tab on page C - 20 .
Final Checks
To ensure optimum operation, inspect the system for crimped or pinched cabling.
Make sure all connections are secure. Once the system has been aligned and is
operating satisfactorily, it will require infrequent and simple maintenance procedures
as described in Maintenance on page 6 - 1 .