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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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