Pwr Mon With Spectrum Analyzer (R-2400 Only); Transmitter Distortion Measurements; Measurement Of Transmitted Pl; Simultaneous Oscilloscope I Dvm Operation - Motorola R-2200 Operator's Manual

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
I I
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.