User's Manual

Table Of Contents
Printed Documentation
146
turn between the TX output and the power meter and measure the loss added as the
component is inserted. Measure (1)A-B, (2)B-C, (3)C-D and (7)D-E.
7. Calculate and enter values in calibration chart for the relevant frequency.
RF Channel No:
Ref TX output
A-B Atten.(1)
B-C Atten.(2)
RF Section
C-D Atten.(3)
Sub Total (4) 1+2+3
Required CT RX Level (5)
see table 1
ST TX Power (6)=4+5
RF Section D-E Atten (7)
Power Meter (8) = 6-7
8. Calculate/determine overall path loss and required ST output power and hence
required power meter reading.
9. Connect cables as per diagram above. Try to ensure that the network is set to reduce
the amount of radiated pick up. To ensure that it is the receive path that is being
measured and not pickup place an attenuator (6dB) into the network and check that
the meter falls by a corresponding amount. If it fails to do so additional screening of
the test network is probably required.
10. Connect a terminal emulator to the ST.
11. Make the test ST transmit by sending the following LAT commands from a terminal
emulator connected to the ST
TE<space> 0<space> 4<space> 59 (this code sets the uplink modulation rate for the
ST see table 1)
FP <space>channel number (in decimal)
W<space> 0400003C
12. The terminal emulator should receive 0000000B for the uplink if the ST has acquired
a link.
13. On the AS4020 go to Top Menu >Setup Menu >RF Menu>RX Sensitivity
14. Set RX gain by increasing/decreasing the value of RX sensitivity to achieve required
ST o/p level as calculated in step 8 for the required RX Level.
15. Record ST o/p level and value set.
Link Check
9. When the link has successfully acquired 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(release
7.2x) or Enabled = 1 Converged = 1(release 7.3x)
Check that the equalizer converges OK.
10. From the ST LAT type TE1 to exit commissioning mode