Terrasat IBUC 3, Operation Manual

Page: 69 / 236

Common Errors
|
4-9
Engineered to Endure
3. Check the signal mix. Remember that low-side is non-inverting and high-side is
inverting.
4. Use the following formulas to calculate IF frequency
low side IF = RF - LO Non-inverting
high side IF = LO - RF Inverting
The LO for each IBUC band is found in Table 2.1 through Table 2.2 .
5. Check the Tx output state.
When Tx output power is disabled, the Tx output level will read - 99.0 dBm. This is
not an actual power reading; rather it indicates the loss of power.
When conditions cause the automatic shut-off of the Tx output signal, the Tx output
level will read - 96.0 dBm. This is not an actual power reading; rather it indicates the
automatic shut-off of power.
Transmit Power in Saturation
The IBUC, at minimum attenuation, makes rated power at - 30 dBm input. Operating
the IBUC at higher levels will result in spectral distortion and high intermodulation
levels. Terrasat recommends operating with power back-off levels sufficient to meet
the spectral density mask.
To avoid signal saturation,
1. Reduce input power from the modem.
2. Increase the attenuation setting of the IBUC.
Tx Input/Output Level Verification
To verify the Tx IF Input level,
1. Establish a connection with the IBUC
3
or IBUC
3
G
by using the steps provided
in Appendix C, Embedded Web Pages .
2. Use the Sensor Tab of the embedded Web pages to check levels.
For more information about the Sensor Tab, see page C-9 .
3. Compare the reading to your expected level.
The detector range is -55 dBm to -20 dBm.
To verify the Tx RF Output level,
1. Establish a connection with the IBUC
3
or IBUC
3 G
by using the steps provided
in Appendix C, Embedded Web Pages .
2. Use the Sensor Tab of the embedded Web pages to check levels.
For more information about the Sensor Tab, see page C-9 .