User's Manual

ST-3118V SM R 1.1 SMARTRUNK SYSTEMS, INC.
18
5.6.4. Modulation Gain alignment:
This is a critical parameter, which
may not be realigned to different
values other than factory default.
Lower gain means a very high
microphone gain must be assigned
to get the proper radio voice
deviation, and higher gain means a
risk because the max deviation
limit must be reached by any
signal, which makes the limiter to
introduce distortion to avoid over
deviation.
Under your risk, if you still prefer to
realign the overall modulation gain,
you must select
Modulator Gain
on Alignment screen.
Figure 17: Modulator Gain Alignment
Actual alignment value will be
displayed on alignment slider.
Press [Start] then move the slider to
reach the desired value at the time
you checks the deviation meter to
reach the desired signaling level for
narrow band operation.
For this alignment step, the radio
does not generate any signal. It only
stores the new value of the overall
modulation gain into the memory.
As soon the desired value is
reached, press [Finish] to store the
value on radio memory.
If you want to retrieve factory
default, press [Factory] instead of
[Start]. You will be asked to confirm
the factory default alignment, and
then, if you confirm it, original
values from factory will be loaded
into current alignment settings.
5.6.5. FDMA DATA MODULATION
alignment:
To align 4FSK signaling deviation
for FDMA mode, select
FDMA Deviation
on Alignment screen.
Actual alignment value will be
displayed on alignment slider.
Press [Start] then move the slider to
reach the desired value at the time
you checks the deviation meter to
reach the desired signaling level for
narrow band operation. Radio will
generate a 1000Hz alignment
reference tone for alignment
proposes.
Figure 16: FDMA Deviation Alignment