Ramsey Electronics COM 3 User manual

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©

COM
3
Service
Monitor
Owner's
Manual
Version
1.7
©
1987
Copyright
1987
by
Ramsey
Electronics
Inc.No
Part
of
this
publication
may
be
duplicated
in
part
or
whole
without
written
permission
by
an
officer
of
Ramsey
Electronics
Inc.

Section 1 -
CONTENTS
General Information
Introduction
Specifications
Options
Special Modifications
Installation
Introduction
Unpacking and Inspection
Power Requirements
Enviromental Considerations
Operation
Introduction
Front Panel Description
Initial Turn On
Generate RF
RF Output Level
FM Modulation
AM Modulation
CTS Tone Generation
1 KHz Internal Tone
External Source Input
Combining CTS and Internal/External
Tone Sources
Offset+ / Offset-
500 Hz Step
Storing/Recalling Test Setups
Spurious Signals
Leakage
Audio Count Off Air
Audio Count External
RF Count
Typical Test Setups
Introduction
Frequency Counter : Off Air
Frequency Counter : Direct Connection
Frequency / Deviation Measurements
20 dB Quieting Measurement
12dB Sinad Measurement

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— A រត:
5.22
5.23
Section
6
-
General
512-1018
MHz
Coarse
Loop
PLL
5-7
MHz
Fine
LoopPLL
.
1024
MHz
Offset
PLL
Output
Step
Attenuator
4
MHz
Reference
Standard
FM
Modulator
AM
Modulator
1
KHz
Source
Receiver
16
KHz
Reference
Generator
Frequency
Error
Detector
Audio Amp
+30
Volt
and-10
Volt
Supplies
Transmit
Protection
Circuit
DC
Supply
and
Battery
Membrane
Switch
Microprocessor
E
Display
Drivers
Audio
Frequency
Counter
RF
Frequency
Counter
CTS
Tone
Generation
Frequency
Error/Deviation
Display
Documents,
Figures
Fig
3.1
Front
panel
layout
Fig
4.1
Block
diagram
Schematic
diagram
Warranty
Test data

ON 1
SECTI
GENERAL
INFORMATION
The
Com
3
is
a
lightweight,
compact
Service
monitor
for
testing
AM
and
FM
transceivers.
The
internal
battery,
which
is
a
standard
feature
of
the
Com
3,
combin
ed
with
the
optional
carrying
case
and
low
weight
(13
lbs),
make
it
ideal
for
field
use.
Utilizing
specially
designed
micro
Powered
oven
circuits,
warm
-up
time
is
minimal,
providing
maximum
use
of
the
battery.
tone
can
be
generated.
RF
power
is
continu
variable
in
five
ranges
from
0.1
uv
to
10,000
uv.
The
display
is
a
seven
digit
LED
type
which
will
display
frequenci
i
i
audio
ahd
RF
frequency
counter.
Deviation
and
frequency
error
are
displayed
on
a
20
segment
LED
bargraph,
which
is
easily
visible
from
across
the
shop.
|
An
internal
RF
relay
switches
transmitted
power
greater
than
500
mW
to
a
rear
panel
mounted
BNC
connector.
This
protects
the
Com
3
from
accidental
keying
and
allows
easy
connection
of
an
antenna,
power
meter,
or
dummy
load.
1-1

1.2
Specifications
1.21
Generate
Mode
1.2.1.1
Frequency
Range
Resolution
Display
Accuracy
1.2.1.2
Rf
Output
Range
Accuracy
Attenuctor
1.2.1.3
Spectral
Purity
Non-Harmonic
Other
1.2.1.4
Reverse
Power
Protection
Type
Power
1.2.1.5
Modulawion
Deviation
Ranges
100
KHz
to
999.999
MHz
500
Hz
7
digit
LED
see time base
0.1
uv
to
10,0000
uv
ind
ranges
+2.0
dB
(10
MHz
to
900
MHz)
20 dB/step
«-50
dBc
within
10
KHz
of
carrier
(all
land
mobile
bands)
2
signals,
f1
and
f2
Forf1
=
(fc
+
Fine
Loop)
10
dB
below
maximum
RF
output
range
selected
Forf2
=
(fc
+
2(
Fine
Loop)
MHz,
same
level
as
fc
Fine
Loop:
5
to
7
MHz,
depending
upon
selected
frequency
Automatically
switches
to
external
load
at
inputs
. >500 mw
Up
to
100
watts
(10
seconds)
FM
0
to
15
KHz
peak
(displays
to
7
KHz
only)
41.5, +7.0 KHz
NIME

1.2.2.2
Bandwidth,3dB
Accuracy
External Input
Depth
Bandwith, 3dB
Accuracy at 30 % mod.
External Input
Receive Mode
Frequency
Range
Resolution
Display
Accuracy
Sensitivity
Bandwidth
Modulation Measurement Mode
FM Mode
Deviation
Ranges
Bandwidth, 3 dB
Accuracy
Display
10 Hzto 10KHz
15% of full scale (1 KHz frequency)
1 vpp for 3 KHz peak |
AM |
0to 99%
10 Hz to 10 KHz
+5% of full scale (1 KHz frequency )
1 vpp for50%
100 KHz to 999.9999 MHz
500 Hz NS
7 digit LED
see time base
5.0
uv
for
10
dB
quieting
(10
MHz
to
900
MHz)
3dB/7KHz
Oto 7 KHz
+1.5, 2 7.0 KHz
10
Hz
to
10
KHz
(display
limited
to
<
7
KHz)
15% of full scale (1 KHz frequency )
20 segment LED bargraph

AM Mode
Ranges
Accuracy
Display
1.2.3
Time Base
Characteristics
STANDARD OCXO
Accuracy + 1.0ppm
Aging rate t 2.5ppm/year
Oper. range 01050?
Stability t 1.0 ppm after
5 minutes at 25 °C
1.25 Frequency Counter Mode
Ranges
1.2.6 GENERAL
Operating temperature
Power requirements
Dimensions
Weight
1.2.7 OPTIONS
High stability timebase
12 VDC cigarette plug
Cordura travel case
Protective front cover
Side Handle
(Carrier frequency error only)
+1.5,+ 7.0 KHz
+5% of full scale
20 segment LED bargraph
HIGH
STABILITY
OCXO
+0.5
ppm,
+
0.25
ppm,
or
0.10
ppm
t
1.0
ppm/
year
01050^ C
ቷ 0.5 ppm after
10 minutes at 25 9 C
10
Hzto
1.0
KHz,
0.1
Hz
resolution
10
MHz
to
999.999 MHz, 1 KHz resolution
0to50?C
117 VAC, or12 VDC
12"Wx5.5"Hx14"D
13 Ibs
An oven controlled oscillator which increases the
accuracy to 0.5 ppm, 0.25 ppm, or 0.10 ppm
depending on which model is selected.
Allows
the
Com3
to
operate
from
a
car's
battery
A
rugged
carrying
case
made
from
black
Cordura
nylon,
with
a
convenient
zipper
pouch
for
holding schematics, probes etc.
Vacuum
formed
plastic
cover
for
protecting
the
Com
3's
front
panel.
Aside
mounted
handle
for
easy
transportation
of
the
Com
3.

1.28
SPECIAL
MODIFICATIONS
Due
to
the
constant
advancements
in
the
two
way
communications
field,
customer
needs
may
require
a
special
modification,
either
at
the
time
of
purchase,
or
some
time
in
the
future.
Contact
the
customer
service
department
at
716-586-3950.
We
will
do
our
best
to
meet
your
needs,
please
note
that
modifications
will
require
a
service
charge,
and
some
may
not
be
possible.

.
2.1
INTRODUCTION
The
Com
3
is
a
rugged,
portable
service
monitor
that
is
equally
at
home
in
the
field
or
on
the
bench.
Refer
to
the
following
sections
when
unpacking
your
service
monitor.
2.2
UNPACKING
AND
INSPECTION
When
unpacking
your
service
monitor
check,
the
shipping
container
and
the
monitor
for
shipping
damage.
Save
the
container
for
future
*
use,
orinthe
event
of
an
insurance
claim.
Your
Com
3
was
thoroughly
tested
and
inspected
,
then
carefully
packaged
prior
to
shipment
and
should
operate
according
to
section
3
of
this
manual.
|
If
your
monitor
was
damage
in
transit,
contact
the
carrier
immediately.
Save
all
shipping
and
packing
materials
for
inspection
by
the
carrier.
Contactthe
carrierto
reportthe
incident.
'
SECTION
2
INSTALLATION
5.3
POWER
REQUIREMENTS
The
Com
3
operates
on
117
VAC
60
HZ.
The
three
conductor
power
cord
provides
a
ground
connection
when
it
is
connected
to
a
properly
grounded
outlet.
Using
the
optional
12
VDC
power
cord,
the
Com
3
can
be
operated
from
a
Car's
battery.
The
Com
3's
internal
battery
cannot
be
charged
from
an
external
DC
source.
NOTE:
Do
not
start
the
engine
while
the
Com
3
is
plugged
into
the
cigarette
lighter.
This
could
result
in
damage
to
the
Com
3.
A
240
VAC
50
Hz
version
of
the
unit
is
available
by
special
order.
There
is
an
addtional
charge
for
this
option.
2.4
ENVIRONMENTAL
CONSIDERATIONS
The
Com
3
comes
equipped
with
bottom
and
rear
panel
feet
(
the
rear
panel
feet
act
as
cord
wraps),
and
a
tilt
bail
.
These
features
allow
the
unit
to
be
used
in
almost
any
situation.
The
Com
3
is
designed
to
operate
`
between
0°
C
and
50?
C.
Care
should
be
taken
to
keep
the
unit
clean
and
dry.
MEM
M