User Manual

SGD-SB2025NT-TUM, Part 1
Jan 12 Page 41 ALIGNMENT & TESTING
4. On the Channel Edit screen, carry out the following:
4.1. Select the ‘Continuous Update Enabled’ tick box. (This allows real-time updating of the
digital potentiometer values and, therefore, any changes made will be immediately
reflected in the radio).
4.2. Alter the ‘Tx RF Power’ digital potentiometer until the power meter reads the required
output power.
4.3. Select the ‘OK’ button to accept the changes made and close the Channel Edit screen.
5. On the Channel screen, on the dynamic tool bar, select ‘Write Channel’ button to save the
changes made to the radio.
To calibrate each channel individually, ensure that the ‘Lock Data’ option is not selected and repeat
the above procedure for each channel.
6.1.9 Peak Deviation and Modulation Balance Configuration
6.1.9.1 Station NI/SB2025
All level setting is carried out with the SB2025 equipment in analogue mode using an analogue
Radio Test Set. A final check of P25 Modulation Fidelity can be carried out at the end if a P25 Test
Set is available.
Notes.
(i). When injecting tones into the NI of the SB2025 base station, it is important to avoid
exactly 1 kHz as the measuring bar graph on the ET is a little unstable at exact sub-
multiples of the 8 kHz sample rate. The level measurement is subject to the 6
dB/octave receive de-emphasis so it is advisable to stay close to 1 kHz. The test tone
frequency used for P25 testing is 1011 Hz, therefore, this can easily be used for
analogue testing as well.
(ii). On the ET, before any changes to settings can be made, the ‘Eng’ button must be
selected. Once any change has been made, the ‘Apply’ button must be pressed for
the change to take effect. Multiple changes may be made and implemented together
with a single ‘Apply’ action. Failure to apply a change will result in the attempted
change being abandoned and settings will revert to their previous state when the
corresponding ‘Eng’ button is released.
Tools, Test Equipment and Materials Required
The following Tools, Test Equipment and Materials will be required to perform this procedure:
• Analogue Radio Test Set (RTS) with external frequency reference for accurate carrier
measurement.
• T36 Module Serial Cable (refer to Appendix C for the required cable details).
• PC with the following software installed:
o Solar 2 Engineering Terminal.
o MxTools.
o HyperTerminal (or similar serial terminal).
Procedure
1. On the SB2025 base station, carry out the following: