User's Manual

SRM9000X8 800MHz SERVICE MANUAL
© TMC Radio 2008 page 51 TNM-M-E-0022 Issue 1
7
Select the
5W
power level.
8
Adjust the
Tx Final Value
slider for a power output of 5W.
9 Repeat step 8 for the remaining 3 Channels (2, 1& 0).
10
Select the
27.5W
power level.
11
Adjust the
Tx Final Value
slider for a power output of 27.5W.
Note that the supply current is less than 7.5A.
12 Repeat step 11 for the remaining 3 Channels (1, 2, & 3).
13
Press
Calibrate TX PA Current
button and follow the prompt to automatically set the maximum
current limit.
14
The
PTT
will automatically dekey after this procedure.
4.1.18
Tx Modulation DAC Alignment
All microphone levels are referenced to the audio level output displayed on the Comms. Analyser and based on <10Ω
source impedance.
NOTE
: This audio signal is fed to the radio input via a series 470Ω resistor and 47uF capacitor in the Audio/ Serial
Interface Adaptor.
General
Dual point modulation is used and there are two settings that need adjusting to meet deviation requirements. The
modulation alignment is set up for 12.5kHz channel spacing. For customer configurations of other channel
spacings, the modulation alignment is automatically adjusted for those settings.
Note that when measuring deviation at 60% MSD the average of the + and − readings should be used. When
measuring maximum deviation, the higher of the + and – readings should be used.