3.2.3 FUNCTION SWITCH
3.2.3.1 GENERATE FUNCTIONS The function switch
is
a
four position rotary switch which permits the service
monitor to be used
as
an
RF
signal generator specified
from
200
kHz to 999.9999 MHz or an
RF
signal monitor
specified from 1 MHz to 999.999 MHz. In the
"HI
GEN"
(high generate) function the unit generates and outputs
an
RF
signal and
is
capable of
200
u V to 1 VRMS output
on any frequency within the specified range. The
1 volt
output level
is
sufficient for transmission through an
antenna connected to the antenna connector. In the
"GEN"
(generate) function the unit generates an
RF
signal for direct connection to the antenna input of the
equipment under service with output levels from
.1
u V to
200 uV.
3.2.3.2 MONITOR FUNCTIONS The "SENS MON"
(sensitive monitor) function allows the unit to monitor
low level signals. The
1.5
microvolt sensitivity allows
off
the air monitoring
of
a remote transmitter's frequency
error and deviation/OJo modulation (of modulated car-
riers). Hookup
is
made to the "ANTENNA" connector.
Selecting the
"PWR MON" (power monitor) function
permits the service monitor to operate as an RF watt-
meter, allowing direct output power measurement
of
transmitters within the range
of
.5
to
125
watts. Fre-
quency error and deviation/OJo modulation measure-
ments are also available in the
"PWR MON" function.
Hookup
is
made to the "RF
IN/OUT"
connector. The
R-2400 has two additional function switch positions,
"Anlzr Sens Mon" and "Anlzr Pwr Mon" which are used
to enter the analyzer mode
of
operation. In "Anlzr Sens
Mon", the signal applied to the "Antenna" input
is
displayed. In "Anlzr Pwr Mon", the signal applied to
the
"RF
In/Out"
input
is
displayed. All other functions
are the same as for
"Pwr Mon" and "Sens Mon".
3.3.0 LIQUID CRYSTAL DISPLAY MODE SELECT
Notice the cursor controls
jl:::t.j
on the left and right
LCD's. These controls select the various measurement
modes. Each time the cursor control
is
depressed the
annunciator
DOT
located on the left side of each LCD
screen
will
move and an audible feedback tone will verify
actuation. The equipment
is
programmed to suppress
measurement modes not relevant to the selected service
monitor function. For example, when
in
the
"GENER-
ATE" function, frequency error and power (on the right
LCD) cannot be accessed. This reduces operation time
and increases productivity. See table
1 for software de-
fined selections.
3.3.1 LIQUID CRYSTAL DISPLAYS
3.3.1.1 ANALOG METER BARS/DIGITAL DISPLAYS
As shown in fig. 3-2 the LCD's provide autoranging
analog and digital displays. Digital displays provide
accuracy and autoranging meter bars assist during peak-
ing and dipping maintenance adjustments. To provide
efficient operation the digital readouts of selected modes
3-2
TABLE
3-1
FUNCTION
ACCEPTABLE
MEA-
SUPPRESSED
MEA-
SWITCH
POSITION
SUREMENT
MODE
SUREMENT
MODE
GENERATE
DEVIATION
ALARM
FREQ
ERROR
HI
GENERATE
DEV/%
AM
POWER
DVM
DISTORTION
SINAD
BATTERY
VOLTAGE
RF
LEVEL
POWER
MONITOR
DEVIATION
ALARM
RF
LEVEL
OR
DEV/%
AM
ANALYZER
DVM
POWER
DISTORTION
MONITOR
POWER
FREQ
ERROR
BATTERY
VOLTAGE
SINAD
SENSITIVE
DEVIATION
ALARM
POWER
MONITOR
DEV/%
AM
RF
LEVEL
OR
DVM
ANALYZER
DISTORTION
SENSITIVE
FREO
ERROR
MONITOR
BATTERY
VOLTAGE
SINAD
are presented at the same time as analog displays. With
display modes selected for
RF
signal measurements such
as FM deviation or frequency error, the meter bars oper-
ate about a center point and show symmetrical or non-
symmetrical deviation
or
drifting about the center fre-
quency. In
"%AM",
the meter bar graph operates about
a center point and shows positive and negative percent-
age of amplitude modulation.
Other
display mode ana-
log meter bars (distortion, power) have zero reference
on the left with autoranging meter bar displays increasing
to the right. SIN
AD
has a "reverse" meter bar graph. As
SIN
AD
values get larger in a range
of
0-20 dB the meter
bar graph gets smaller. The voltmeter display,
"DVM",
has left to right meter bars for all AC signals and positive
DC
signals. For negative
DC
signals, the meter bars
move right to left with zero reference at the right.
3.3.1.2 SPECIAL DISPLAY SELECT SWITCHES Three
special membrane switches are provided to control the
digital volt meter,
RF
level and deviation/percent AM
modes. The
j
~i~
..
J
is
used to select the FM deviation
or
AM
modulation positive
or
negative peaks. In the
"DEV/%AM"
measurement mode, deviation
is
auto-
matically selected if in FM and
%AM
is
automatically
selected if in AM. The
j:C:cj
is
used to select the display
for either
AC
or
DC
voltages and the
jV/:~mJ
provides
the
"RF
LEVEL"
digital readout
in
volts
or
dBm. These
keys will respond only when the associated function
is
active.
"'-""
i
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