4.4.2.1
PWR
MON
WITH
SPECTRUM ANALYZER
(R-2400 only)
For
high power signal monitoring (.5 to
125
watts)
1.
Connect the radio under test antenna out to the
"RF
In/Out"
connector on the service monitor.
2. Set the function switch to
"Anlzr Pwr Mon".
3. Adjust the Vertical and Horizontal position controls
if
necessary (see 3 .6.8).
4.
Enter the RF frequency from the keyboard.
5. Move the right cursor to
"PWR".
6.
Adjust the RF Step attenuator for maximum attenu-
ation
(70 dB)
7.
Key
the radio under test and adjust the RF step at-
tenuator for the desired viewing level.
8.
Read the output power on the LCD display.
4.4.3
TRANSMITTER
DISTORTION
MEASURE-
MENTS IN
THE
PWR MON FUNCTION
The
distortion
meter
display can be viewed in either
Generate
or
Monitor function.
The
distortion meter
measures the quality of the audio.
1.
Connect the
RF
IN/OUT
to the radio antenna jack
and connect the modulation output to the radio mic
input. Connect the
DEMOD
output to the multi-
purpose input BNC connector. This allows the unit to
be used as a test receiver.
2.
Enter the
RF
Frequency
EJCD000000EJ
3.
Set the function switch to Pwr Mon and
j~J
to Dist.
4.
To display modulation waveforms of the transmitter
turn the oscilloscope source switch to
"MOD."
5. Adjust the I kHz tone level for proper deviation. (out
of clipping) Disable
PL if resident
in
the transmitter.
6.
Read transmitter audio distortion
in
% on the digital
readout. Note that transmitter power and frequency
error
can also be displayed on the right LCD.
RF
IN/OUT
~
D
Gen154.5500
II
3.3%
L______j
Vert/SINAD DEMOD
Dist!DVM
OUT
TRANSMITTER
FIGURE
4-5-TEST
SET-UP FOR
TRANSMITTER DISTORTION MEASUREMENT
4.4.4
MEASUREMENT
OF
TRANSMITTED
"PL"
TONE
With the internal
PL
frequency counter it is possible to
measure the
PL tone
of
a transmitter. The function
switch can be moved to either monitor function position.
1.
Select the PL Count mode located
in
the modulation
section using the [
~
J cursor.
2.
Select SENS MON (sensitive monitor) for off-the-air
monitoring.
3.
Enter
the frequency from the keyboard.
EJCD000000EJ
4.
Key the transmitter under test and read PL frequency
in
the upper portion
of
the right LCD.
NOTE:
The
PL frequency counter measures frequency
inputs
in
the range
of
60Hz
to 270Hz. The output
of
the
counter
is
displayed on the right LCD with resolution of
.1Hz.
In cases of low PL tone deviation, the value
of
the
tenths digit may fluctuate periodically.
It may be neces-
sary to average the displayed values over time to deter-
mine the
PL frequency within
.5
percent accuracy.
I Mon 154.5500 I
~
ANTENNA
FIGURE
4-6-
TEST SET -UP FOR
PL COUNTER MEASUREMENT
4.4.5
SIMULTANEOUS
OSCILLOSCOPE/DVM
OP-
ERATION
The
use
of
separate
CRT
and
LCD
displays makes it
possible to view signal waveforms on the oscilloscope
and simultaneously view the measured digital and analog
values of the waveform on the left LCD. To measure an
AC waveform (RMS value) and display the waveform on
the oscilloscope CRT:
1.
Connect the multipurpose input test probe to the
circuit to be measured.
4-4
2.
Move the left
[~\cursor
to DVM and select
AC
volts
for display.
3.
Select the
EXT
AC
position on the oscilloscope
"SOURCE"
switch.
4.
Select the
proper
Volt
per
division scale and center
the trace.
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