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9.33 uV
-87.5DBM
+ 12.1 DBM
V AC
3.00
0
300
DVM MODE
MODE SEL) 1
1) AC VOLTS
2)
DC VOLTS
3) DISTORTION
BAT 11.0V
ANT
',---",
WARNING
FIGURE 3-36.
AC DVM DISPLAY
THE METER'S COMMON LEAD IS CONNECTED
TO THE ANALYZER'S CHASSIS GROUND. DO
NOT ATTEMPT TO MEASURE FLOATING CIR-
CUITS WITH THE ANALYZER, BECAUSE THAT
WOULD CONNECT THE FLOATING CIRCUIT TO
GROUNDl FOR EXAMPLE, DO NOT MEASURE
AC POWER MAINS WITH THE ANALYZER.
SERIOUS SHOCK HAZARD COULD RESULT.
'----'"
04) 285.7750 MHZ
DPL) - --
RF LEVEL
GENERATE FM
PL) 035.0
and the corresponding dBm value. Use the voltmeter to
check audio level, bias level, and power supply voltage.
The voltmeter operates in generate or monitor function.
Connect the probe RTL-4011A to the Vert/Sinad/Dist
connector. Move the cursor to the mode select position.
Select AC, DC, or DISTORTION mode, as required.
Implement fixed ranges with special function control
techniques.
• FREQUENCY COUNTER
Figure 3-35 shows a Frequency Counter display. The in-
ternal Frequency Counter measures input from 10 Hz to
35
MHz. To measure signals higher than 35 MHz, use
the frequency error readout in the monitor mode. The
CRT displays an autoranging output allowing the oper-
ator to measure precisely and set offset oscillators, IF's,
PL frequencies, and other external input signals. Fre-
quency counter operates in either generate or monitor
function. Use PL/DPL decode modes for measuring
these codes off the air. Enter number 1 or 2 to select
either frequency counting or period counting. In the
counting mode, select one of the five display resolutions
or automatic ranging. Frequency counting is preferred
above 1 KHz. Period counting is preferred below 1
KHz. Adjust sensitivity with the OSCILLOSCOPE Vert
switch and vernier. For best results, set the control for a
90070 of full-screen deflection. Too little signal causes a
NO INPUT SIGNAL indication on the screen; too high
causes wandering or erroneous readings. The display
shows the calculated input frequency, the five digit fre-
quency readout with operator selected resolution, the
acronym for the multiplier (Hz, KHz, MHz) and posi-
tion of the decimal point as identified in table 1. The
system automatically ranges to display the best resolu-
tion of the input frequency consistent with table
l.
If
the
operator selects a resolution inconsistent with table 1,
an appropriate warning message: INCREASE RESO-
LUTION or DECREASE RESOLUTION replaces this
entire line. The processor programs for a new resolution
and attempts a new frequency reading. When the proc-
essor updates a frequency, the asterisk on line 12 blanks
for 0.1 second. The warning message displays on line
14, whenever the input range attenuator is not in its
most sensitive position. Table 3-11 lists the relationships
between frequency and resolution.
Counting
Multiplier
Resolution Hz
Frequency
0.1
1
10
100
1000
-
Hz
0.0-6000.0
NA
NA
NA
NA
Figure 3-36 shows an AC DVM display of the center fre-
quency and the PL or DPL code in the generate mode.
The bargraph responds to the magnitude of the voltage
in a modified logarithmic manner to provide a smooth
nonranging analog display. Line 14 displays the voltage
of the primary DC power source.
MONITORFM
04) 400.0000 MHz
KHz
NA
0.0-6000.0 0.0-600.0 0.0-6000.0
NA
+24.0DBM
INPUT LEVEL
3.3 V
MHz
NA
NA
NA
NA
0.0-35.0
V DC
+.001
Period
----
0
300
Hz
2.0-999.9
10-2999
NA
NA
NA
DVM MODE
MODE SEL)
2
1) AC VOLTS
KHz
NA
NA
0.0-9.99
0.0-29.9
0.0-99.9
2)
DC VOLTS
3)
DISTORTION
BAT 0.0 V
MHz
NA
NA
NA
NA
NA
ANT
TABLE 3-11.
VALID INPUT FREQUENCY VERSUS
DlSPLAY RESOLUTION
FIGURE 3-37.
DC DVM DISPLAY
• (DVM/DIST) DIGITAL VOLTMETERI
DISTORTION MODE
The Analyzer provides an AC-DC voltmeter. The volt-
age automatically ranges between full scale values of 1,
la,
100, and 300 volts. The CRT displays the voltage
3-18
"--../
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