Terrasat IBUC 3, Operation Manual

Page: 64 / 236

4-4
|
IBUC
3
, IBUC
3 G
Operations Manual: Operations
Engineered to Endure
Setting the Tx Frequency (L-band)
Changing the L-band frequency will cause a change to the RF frequency. To set the L-
band frequency,
1. Establish a connection with the IBUC
3
or IBUC
3 G
by using the steps provided
in Appendix C, Embedded Web Pages .
2. Navigate to the Information tab as shown on page C-4
3. Verify the data in the Band Inversion field.
4. Calculate the IF frequency by using the following formulas:
IF = RF - LO Non-inverted/Low side
IF = LO - RF Inverted/High side
Note:
RF and LO frequencies for various bands are provided from Table 2.1 on page 2-3
through Table 2.2 on page 2-4 .
Setting Alarm Thresholds
Although the IBUC will function using the factory-configured settings, by setting high
and low level thresholds for the Tx Input/Output you can access more information
about events such as power fluctuations that might trigger an alarm.
Alarms will be generated when the input and output amplitudes fall outside of the
threshold ranges. For this reason, Terrasat recommends that once the user has reached
the proper input and output settings for their budget, to narrow the threshold ranges for
alarms. To display or set alarm thresholds,
1. Establish a connection with the IBUC
3
or IBUC
3 G
by using the steps provided
in Appendix C, Embedded Web Pages .
2. Navigate to the Tx Configuration Tab to display/set the Tx Input High/Low
thresholds.
The IBUC leaves the factory with a default range of
- 15 dBm to - 60 dBm.
Example
: After observing the unit, you determine that the IBUC operates
consistently at - 37 dBm. Although the threshold range is 45 dB, that range is too
wide for everyday use. Instead consider setting the input thresholds at ±3 dB; this
would make the high level threshold - 34 dBm and the low level threshold - 40 dBm.
Note:
You will receive an error message if the input level exceeds the threshold range.
3. Set the Tx Output High/Low thresholds.
When you set up your system and the Tx Output reaches its budgeted level, Terrasat
recommends that, instead of the (P1dB - 20 dB) to (P1dB + 1 dB) threshold range
that is the default, you narrow the range between the high and low thresholds to
±3 dB.