Modulation Section; Fixed Ikhz Tone; Code Synthesizer; Modulation/Function - Motorola R-2001D Operator's Manual

A typical Amplitude Modulation display screen (figure
3-6) shows set frequency, frequency error, percent AM
modulation,
and
RF
input level.
- -) 101.1000 MHZ MONITORSSB
--.- DBM
BFO
-15
INPUT LEVEL
ERROR KHZ
°
--.- W
+3.62
+ 15
3.3 MODULATION SECTION
Figure 3-9 shows the connectors, controls, and indica-
tors located in the front panel MODULATION section.
The modulation generator provides the RF generator
with the modulating signal internally connected to either
frequency, amplitude, or sideband function. The modu-
lating signal sums the inputs of three sources: Internal
fixed 1 KHz test tone, multimode audio code synthe-
sizer, and external inputs. Adjust the level of each
source independently. The modulating signal is avail-
able at the Mod Out BNC connector.
FIGURE 3-7. SSB DISPLAY
A typical Single Side Band display screen (figure 3-7)
shows set frequency, RF input level, and BFO frequency
error. Modulation data is not monitored.
GENSWP
RF LEVEL
- -) 101.1000 MHZ
• FIXED 1 KHz TONE
A I KHz test tone provides a convenient modulation
source for general troubleshooting,. SINAD and DIS-
TORTION measurement, and distortion measurement.
Adjust the level with the 1 KHz Level control. The Off
position turns off the 1 KHz tone.
• CODE SYNTHESIZER
FIGURE 3-8. SWe DISPLAY
A typical Sweep display screen (figure 3-9) shows only
set frequency and RF output level. Modulation data is
not monitored. In sweep function, select either 0.01-1
MHz or 1-10 MHz range. Use the Dispr/Sweep vernier
to control the sweep width. The minimum position is
fully counterclockwise and the maximum position is
fully clockwise.
The code synthesizer generates either a single tone, a
multitone sequence, or a DPL sequence in response to
front panel and CRT display inputs. Press a MODULA-
TION arrow key to select one of the six modes:
419mV +5.4
DBM
PLlDPL
PLlDPL Inv
Tone A
Tone B
Tone Seq
Tone Remote
Private Line/Digital Private Line
Private Line/Inverted Digital
Private Line
Tone A frequency only
Tone B frequency only
Signaling Sequence
Remote Base Control Sequence.
Tone Seq
• Tone At"nlote
Use the keypad to select frequencies in the 5 Hz to 1,000
Hz range for PL or DPL modes and in the 5 Hz to
20,000 Hz range for the other modes (0.1 Hz in-
crements). The MODULAnON toggle switch initiates
the programmed tone sequence:
Cont - Continuous position generates repetitive
cycles
Off - Position terminates modulation
Burst - Position generates a single tone sequence.
Table 3-1, Modulation/Function, tabulates what works
when.
Cqde
S~'nlh
Lvi Eli! L 1101
FIGURE 3-9. MODULATION SECTION
3-3
MODULATION
Code
Synth
Mode
°PL/DPL Inv
°Tone A
°Tone B
FUNCTION
A vailable only in FM Generate or
FM Duplex Gen.
Available only in FM Generate or
FM Duplex Gen.
Available as Modulalion
jn
FM,
AM, or SSB FUNCTION only in
Generate position. Available at
Mod Out jack, at all times if
selected, in both Generate and
Monitor positions.
Same as Tone A.