Motorola R-2200 - 3. 7.3 Bandwidth Control- Wide;Narrow; Modulation Section; General; Microphone Connector

3.6.9 TRIG MODE
The triggering mode is a three position rotary switch and
se lects the scope triggering mode or can turn the scope
~ff to save power .. '' AUTO" (automatic) provides a co n-
tmuou s swee p With no vertical input. The "NORM"
(~ormal) position requires an externa l vertical input to
tngg er a swee p. The "SCOPE OFF" position turns off
the scope. This will extend bat t ery o perating time.
3.6.10
TRIG LEVEL
The triggering level potentiometer adjusts the scope trig-
ger voltage.
3.6.11
VERT/SINAD/DIST DVM
Muhi-purpose input. Also located in th e oscilloscope
section is a BNC connector to connect signals to the unit
for the following functions:
1. External vertical inputs for osci ll oscope operation.
Sensitivity ranges from 10 mV /div to 10 V/div.
2.
S IN AD meter input range is .5 V to 10 VRMS.
3. Di st ortion meter input range is .5 V to 10 YRMS .
4. Digital Volt Meter input . Accepts AC and DC volt-
ages and provides 3 digit a ut oranging sca l es of
1,10,100 and 300 volts full sca l e.
NOTE: An extreme over lo ad cond iti on to the oscilloscope
could result in activating input protection circu itr y which
can induce reading e rrors on a ll measurement modes
using the multipurpose input connec tor. This will only
occur with the osci ll oscope vertical input sensit ivity set
much too sensitive for the signal being measured, and the
viewed oscilloscope signal is obviously overload ing and
detlecting far off-screen.
3.7.0 MONITOR S EC TION
MONITOR
e volume 0 Squelr.h
Sigl vi
•
Image BW
H1 Wide
Lo Nar
Demod Out
FI GURE 3.6-CLOSEUP OF MONITOR SECTION
3-9
3.7.1 VOLUME / SQUELCH Th e volume control adjusts
the spea ker output level. The squelch contro l adjusts the
thre shhold level. Full counter clockwise disables the
squelch.
NOTE: Monitor sens itivity is greatly decreased as the
s qu elc h control is increased clockwise beyond the no-
SlJUCich squelch point.
3.7.2 IMAGE HJ /L O
In either monitor mode this toggle switch selects the fre-
quency of the l oca l oscillator injection above or below
the programmed monitor frequency to remove image in-
terference. The normal position is "LO". When a signal
unsquelches the receiver, flipping the switch to "HI GH"
will verify that the signal being monitored is at the pro-
grammed frequency and not a receiver mixing image.
This switch is also used to identify images when the
R-2400 spectr um analyzer is being used.
3.7.3 BANI)WJDTH WLI>E/NARROW
In either "P WR MON " or "SENS MON '" functions this
switch selects
the IF bandwidth. Narrow band is ±10
kHz modulation accep t ance used for most 2-way radio
communication systems and wide band is ±75k Hz mod-
ulation acceptance used for commercial FM br oadcast
monitoring or locating a signal when th e exact frequency
is not known .
3. 7.4 DEMOD OUT
The demod out BNC connecto r provides r eceiver audio
output. Out put signals can be used for transmitter distor-
tion measurements or for external frequen cy counters.
3.8.0 MODULATION SECTION
3.8.1 GENERAL
The multimode code synthesizer contains all controls
used to generate an audio signal. Starting with a sinusoid-
al
one kilohertz tone oscillator. the section al so inclu des
c~pability to modulate a carr i er with PL ,DPL, JDPL ,
smgle tone or two tone paging type signa lling. A four pin
microphone connector is avail ab le for voice modulation
and a BNC con n ector is available for input from an
ex t ernal signal generator. An important feature is the
capability to do si multan e ou s modulation. It is possible
to combine voice, any si n gle code available from the
code synthesizer and a 1kHz test tone in orde r to provide
composite signals for complete testing.
3.8.2 l KHz LEVEL
An internal 1 kHz tone modulati on l evel cont rol is pro-
vided. When in the full cou nterclo ckwise position the 1
kHz source is disabled. Modulation l eve ls can be viewed
by selecting ·'Dev/%AM" on the left L CD and opera tes
in any selected function switch position.
3.8.3 EXT MOD IN
A BNC co nn ecto r is provided for external modul ation
sig nal input s.