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Operations Manual: Transmit Redundant Systems
Engineered to Endure
Transmit Power Setting
There have been several cases where the transmit power has been turned up to or near
saturation while transmitting a digital carrier. This most likely will result in spectral
distortion, re-growth, and intermodulation products for multi-carrier operation.
When transmitting digital carriers, it is customary to operate the power amplifier
system with an output back off (OBO) sufficient to meet the spectral density mask
requirements and the interference requirements of multi-carrier operation.
Tx IF Input Level Verification
If low or no Tx output power is detected, start the troubleshooting by checking the
input to the Tx Redundant System. Use the following procedure:
1. Check the Tx Input Level displayed in any of the IBUC M&C interfaces or discon
-
nect the cable at the IBUC J2 (Tx L-band) connector and use a spectrum analyzer
to measure the power level of the L-band signal at the output of the coaxial cable
that connects to the IBUCs at J2 (Tx L-band). The L-band signal level should be
between -20 dBm and -55 dBm. If it is not, check the cable and modem output.
2. If the L-band signal is good, check that the 10 MHz reference signal is b5
dBm and -12 dBm and is free of distortion. If it is not, check the cable and modem
output (or IFU Tx Output).
3. If the L-band and 10 MHz signals are within specifications, check that the DC
voltage level is within range (for DC-powered IBUCs). The DC voltage will be on
!
CAUTION
1. If both BUCs are operating without alarms, ensure that the A: side unit
is online before leaving the transmitter site. Doing so will enable protected
mode.
2. Before upgrading a transmit redundant (Tx 1+1) system, ensure that
you have downloaded the latest firmware from the Terrasat website at:
Summary of Contents for IBUC 3
Page 8: ...vi Engineered to Endure ...
Page 12: ...viii Engineered to Endure ...
Page 14: ...x Engineered to Endure ...
Page 33: ...System Components 2 11 Engineered to Endure Figure 2 3 DC powered IBUC3 Block Diagram ...
Page 37: ...System Components 2 15 Engineered to Endure Figure 2 4 DC Low Power IBUC System Configuration ...
Page 40: ...2 18 IBUC 3 IBUC 3G Operations Manual Functional Description Engineered to Endure ...
Page 60: ...3 20 IBUC 3 IBUC 3G Operations Manual Installation Engineered to Endure ...
Page 90: ...6 8 IBUC 3 IBUC 3G Operations Manual Troubleshooting Engineered to Endure ...
Page 132: ...B 8 IBUC 3 IBUC 3G Operations Manual Using HyperTerminal Engineered to Endure ...
Page 157: ...Menu Options D 3 Engineered to Endure Figure D 3 Hand held Terminal Menu Tree ...
Page 162: ...D 8 IBUC 3 IBUC 3G Operations Manual Hand Held Terminal Menu Tree Engineered to Endure ...
Page 227: ...Data Sheets G 7 Engineered to Endure ...
Page 235: ...I n d e x 3 Engineered to Endure ...
Page 236: ...I n d e x 4 ...