Configure Modem and Verify Rx Lock
Setup Procedure
7-22
Ocean TRx™ 4500 Installation and Operations Manual
The OceanTRx
TM
4-500 system can be configured to perform periodic checks to verify that
the antenna is locked on the right satellite, provided that the necessary satellite
information can be obtained.
The IRD Lock function checks the status of a Lock/Unlock indication returned from the
modem at a predefined interval. Since there are numerous parameters defining a given
data stream (for example, frequency, modulation, data rate, coding, rate of forward
error)
To validate
1. Set the
Mode
menu to
Acquire
and verify CPI with satellite operator.
2. If CPI is OK, save the configuration (press
V
on the keyboard); otherwise, repeat the
process.
3. For 1dBc, test:
Verify with NOC operator that the antenna Tx is within the valid range.
You may be required to change the Modem TX power level in order to increase CW
carrier.
Depending on your modem vendor, you may be required to perform additional
operations, according to instructions given by the satellite operator.
7.9.2
Fine Adjustment (1dBc)
To set the modem power to drive the BUC to 1dB compression:
1. Activate ‘Tx on’ in the modem.
NOTE:
Use the coarse typical calculated values as a starting power level (to avoid
BUC
saturation).
2. Raise the modem power 1dB at a time while monitoring the signal on the HUB
Spectrum Analyzer (1dB of power corresponds to a 1dB increase in signal level).
3. 1dB compression is achieved when a 1dB increase of modem power causes less than a
0.5dB increase in the signal level. Do not increase the power beyond this point,
because it will drive the
BUC
into compression.
