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The specific entry fields are as follows:
Preset
The preset function is the same as in the
Monitor mode.
B/W
Selects either wide or narrow bandwidth of the
unit via softkey selection. Narrow bandwidth is
typically used for Project 25.
Freq
Enter the desired generate RF frequency using
keypad or TUNING knob.
Output Lvl
Selects generator output level in 0.1 dBm steps
over the range of -130 dBm to 0 dBm. An
alternate display of generate level in microvolts
is available in two ranges depending upon
which output port is selected:
The range of -80 dBm to 0 dBm is
available when the high level GEN OUT
port is selected.
The range of -130 dBm to -50 dBm is
available when the RF I/O output port is
selected.
Gen RF Out
Selects the RF output port via softkeys. The
RF I/O port is recommended for most
applications.
GEN and MON ports are
combined for a single connection to the radio
under test.
The GEN port is recommended
where higher levels are needed. Selection of
the GEN port is indicated by a red LED
adjacent to the GEN OUT connector.
CAUTION
Do not apply input power to the GEN OUT port.
In the event RF power is inadvertently applied, the
port is protected by an in-line RF fuse.
may be accessed by unscrewing the front of the
BNC connector out of the front panel.
21-9
PROJ 25 CONV AUDIO/
MODULATION CONTROL
The Audio Zone, located at the lower right of the
screen (Figure 21-13), is used to control the
multipurpose audio synthesizer section of the unit.
Signals generated by the audio synthesizer are
coupled internally to the generator modulation
input as well as to the MOD OUT connector on the
front panel. The primary categories of modulation
in PROJ 25 CONV mode are Voice Frame, 1011
Hz tone test pattern, calibration test pattern, and
silence pattern. Many of the features available in
standard mode are not available in PROJ 25 CONV
mode.
accommodate testing of Project 25 radios and
equipment.
Each modulation signal has a cursor field for
entering its desired level.
TUNING knob to enter the desired level. An
additional cursor field, adjacent to each level entry,
is used to enable or switch each selection on and off
using softkeys. This field is located at the extreme
right side of the zone.
conditions for this softkey selection.
CONT activates continuous ON condition,
or continuous cycling if a sequence has
been selected. A "~" symbol is indicated at
the extreme right, adjacent to the level to
indicate continuous ON.
OFF switches off the modulation source.
Off is indicated by an "X" at the extreme
right, adjacent to the level.
21-9.1 Modulation Sources
In addition to Voice Frame, 1011 Hz tone test
pattern, calibration test pattern, and silence pattern,
there are two other modulation sources selectable in
the Audio Zone, a Fixed 1 kHz tone and an
External signal.
This fuse
269
The Audio Zone has been changed to
There are two possible
Use the keypad or
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