User's Manual

Setup and Test
139
attenuators
c Power meter reading with coupler
d Difference between readings
e
Coupler loss
if [c] is greater than [b] then subtract
[d] from [a]
if [c] is less than [b] then add [d] to [a]
Table 2
11. Populate the table below with values obtained from calibrated components and
planned levels to calculate/determine overall path loss and required ST output power
and hence required power meter reading.
RF Channel
No:
Cable Loss(1)
Coupler loss loss.(2)
RF Section
Loss Antenna-
CT( DACU RF Module).(3)
Sub Total (4) = 1+2+3
Required CT RX Level (5) See table 1 above.
DACU RF Power (6)=4+5
RF Section Loss Antenna - Power Meter (7)
Power Meter (8) = 6-7
Table 3
12. Make the test ST transmit by sending the following LAT commands from a terminal
emulator connected to the DACU
TE<space> 0<space> 4<space> 59 (this code sets the uplink modulation rate for the
ST for other required modulations replace the 59 with the session ids shown in table
1 above and should be set to the maximum modulation rate required)
FP <space>channel number (in decimal)
W<space> 0400003C
13. The terminal emulator should receive 0000000B for the uplink if the ST has acquired
a link.
14. On the AS4020 top panel go to Top Menu >Setup Menu >RF Menu>RX Sensitivity
15. Set RX gain by increasing/decreasing the value of RX sensitivity to achieve required
ST o/p level calculated as ( 8) in the table above for the required RX Level measured
on the power meter.
16. Record the value set in the test results
Link check
1. Enable the equalizer by typing the following LAT commands
ADE 1 10 (this enables the downlink channel equalizer and it should converge within
10 seconds)
ADS (this command displays the equalizer stats).
When the equalizer is adapting the stat reports Enabled = 1 Converged = 0
When the equalizer is adapting the stat reports Enabled = 0 Converged = 1 (the 0 for