User's Manual

Table Of Contents
Printed Documentation
138
3. Calculate/determine total path loss and required DACU output power and hence
power meter reading.
4. Connect cables and equipment as per diagram below using 30+30+20dB calibrated
attenuators. If coupler calibration known set up as in step 9 and go to step 6
5. Zero power meter. Calibrate and apply measurement offset for operational frequency
if applicable.
6. On the AS4020 go to Top Menu >Setup Menu >RF Menu>RX Sensitivity. Set RX to
2500
7. Put AS4020 Shelf into test mode Off and then into test mode 3. (from AS4020 menu
select Setup Menu/RF Menu/RF Commissioning)
8. Configure the DACU using AS7020STMON according to modem shelf properties to
the correct frequency, PN code and ID number prior to entering test mode. If the
frequency can be entered using STMON then the FP command in the step 12 is not
necessary). If coupler calibration known go to step 11. The commissioning procedure
described in this document is not restricted to any particular RF channel or PN code.
However the user should make sure that both the CT and ST are programmed with
identical RF channel and PN code.
9. Using the values of the calibrated attenuators and cable calculate the loss of the
attenuators and cable between the DACU and CT as per diagram above: Note the
power meter reading.
10. Replace the calibrated attenuators with the coupler and note the power meter
reading. If the power meter is more than the previous one then the difference should
be added to the sum of the attenuator values and of less it is subtracted from the sum
of the attenuator values. This new value represents the attenuation of the coupler.
Attach a label with loss value to the coupler.
a Sum of calibrated attenuator losses
b Power meter reading with calibrated