B+K precision 1050 User manual

TEST INSTRUMENT SAFETY
WARNING
Normal use of test equipment exposes you to a certain amount of danger from electrical
shock because testing must often be performed where exposed high voltage is present. An
electrical shock causing 10 milliamps of current to pass through the heart will stop, most
human
heartbeats. Voltage as low as 35 volts de or ac rms should be considered dangerous
and hazardous since
it can produce a lethal current under certain conditions. Higher
voltage poses an even
greater threat because such voltage can more easily produce a lethal
current. Your normal work habits should include all accepted practices that will prevent
contact with exposed high voltage. You will significantly reduce the risk factor if you know
and observe the following
safety precautions:
1. Don't expose high voltage needlessly in the equipment under test. Remove housings
and covers only when necessary. Turn
off equipment while making test connections in
high-voltage circuits.
2. Voltages of 325 Vdc and 120 Vac are present inside the Model 1050 Telephone Ana-
lyzer; servicing this or any
other electrical instrument should be performed only by
qualified
electronics technicians trained to work in the presence of high voltage.
3. If possible, familiarize yourself with the equipment being tested and the location of its
high voltage points. However, remember that high voltage may appear at unexpected
points in
defective equipment.
4. Use an insulated floor material or a large, insulated floor mat to stand on, an insulated
surface on which to place equipment; make certain such surfaces are not damp or wet.
5. Do not insert fingers or metal objects into either TELEPHONE TEST JACK. When-
ever the analyzer is
on and the DIAL MODE/CONT. button is engaged, 48 Vdc is
present at these jacks. Also, ringing voltages between 35 Vrms and 100 Vrms are
present at TELEPHONE TEST JACK 11, the telephone cord, and the telephone during
the ring
test. If telephone insulation is cracked, nicked, split, or bare wire is ekposed,
the cord should be replaced immediately to prevent electrical shock.
6~ Use the time-proven "one hand in the pocket" technique while handling an instrument
probe. Be particularly careful to avoid contacting a nearby metal object that could
provide a good ground
return path.
7. When using a probe, touch only the insulated portion. Never touch the exposed tip
portion.
8. When testing ac powered equipment, remember that ac line voltage is usually present
on some power input circuits such as the on-off switch, fuses, power transformers,
etc. any time the equipment is connected to an ac outlet, even if the equipment is
turned off.
9. Never work alone. Someone should be nearby to render aid if necessary. Training in
CPR (cardio-pulmonary resuscitation)
first aid is highly recommended.

INSTRUC'DON MANUAL ADDENDUM
for
MODEL 1050 TELEPHONE ANALYZER
Additional Information On Troubleshooting Cordless And Corded Telephones.
Some
of the early users of the Model 1050 Telephone Analyzer have passed along some
additional suggestions on troubleshooting corded and cordless telephones that you may find
helpful.
Although the manual
s~gests a ring threshold of 40 volts rms, this somewhat overstates the
worst case condition. FCC regulations require the telephone companies to provide a minimum of
45 volts ring signal. Thus, 45 volts is a preferred ring voltage threshold for servicing
application. 40 volts would be a good threshold value for a manufacturer's test of new
telephones, allowing a cushion for possible performance degradation over a long period of usage.
It was also pointed out that the manual does not give a recommended frequency tolerance for
guardtone. The guardtone generator in the portable unit and the guardtone detector in the base
unit should be within ±50 Hz of each other for satisfactory operation.
Another fact to consider is that many of the newer cordless telephones use a PLL (Phase
Locked Loop)
rather than a filter for guardtone detection. For telephones that use a PLL for
guardtone detection it is actually just as easy to adjust the guardtone detector (the PLL has a
frequency adjusting potentiometer) as it is to adjust the guardtone generator. Because a PLL is
used, range would not be effected by offset guardtone. With a PLL system, the cordless
telephone would
not function at all if the frequency is off by enough to prevent the PLL from
locking on to
the signal.
491-294-9~01

ADDENDUM
to
INSTRUC110N MANUAL
for
MODEL 1050
TELEPHONE ANALYZER
It has been discovered that step number 9 on page 40 of the Model 1050 Instruction
Manual is
incorrect. Step number 9 should read as follows (underscored represents added
information):
9. Plug another telephone into the AUDIO IN modular telephone jack, select the EXT
&: INT mode of RF OUTPUT, and turn on the EXT MOD LEVEL control (keeping all
other controls and connections undisturbed). Turn off the 1 kHz MOD LEVEL (turn
the control fully counterclockwise). While speaking into one telephone's
mouthpiece (the one plugged into the AUDIO IN jack) you should be able to clearly
hear what is said at the earpiece of the other telephone (the one plugged into
PHONE TEST JACK 12).
491-318-H01

Instruction Manual
for
Model
1050
TELEPHONE
ANALYZER
DYNASCAN
CORPORATION
6460 West Cortland Street
Chicago, Illinois 60635

---------------------
TABLE OF CONTENTS
Page
TEST INSTRUMENT
SAFETY
................... inside front cover
INTRODUCTION .............................. 1
FEATURES .................................... 3
SPECIFICATIONS ••.•••••.•••......••..••••.•• 5
DEFINITIONS OF TERMS
..•.•••••.••••••.•.•• 9
CONTROLS AND INDICATORS
............. 11
OPERATING INSTRUCTIONS ............... 17
Initial Setup ................................ 17
Non-rf Tests ................................ 18
Cord Test ••.. •. ••. . .. . .. ••. . .•. .. .•. . •. .. 18
Dial Test .................. ............... 19
Ring Test ......•........•.......••...•... 20
Voice Level Test •••...••••••••••..•...•• 22
Voice Quality Test ••••.•••.•.•.•.••.•.•. 23
Cordless
Telephone Test ••.••.•••.••••.. 23
Answering Machine Test ••••.•.••.••.••. 23
Automatic Telephone Dialer Test ••••.• 25
The Telephone Analyzer As A
Demonstrator ...•..................•.. 25
RF-Tests .................................... 26
Channel Selection ....................... 26
Receiving Signals ••••.•••••••••.••.•••••. 27
Transmitting Signals ••.••••..•••.••••.•• 36
Additional Information .••.•.••.••.•.•••. 40
WHAT'S INSIDE YOUR TELEPHONE? •••••• 42
Standard Telephone Operating
Characteristics ••••••.••..••••••••••••.•• 42
Block Diagram Analysis •••••••••••••••••••. 45
Schematic Diagram Analysis ••••••••••••••• 46
WHAT MAKES YOUR TELEPHONE
OPERATE? ................................. 48
Introduction ................................ 48
Incoming Calls .............................. 49
"Outgoing
Calls .............................. 49
Page
TELEPHONE TROUBLESHOOTING
CONSIDERATION
•••.•.•••.•.••••.••.•••••• 52
TROUBLESHOOTING CORDED
TELEPHONES
.••.••••••.•••.••..••..••••..• 54
Checking The Telephone's Weak Link;
The Cords.. . . . . . . . . . .. . . . . .. . . . . .. . . . . . . . 54
Checking Ringing.. ••.. . ••. . ••••••••••••••.• 54
Checking Dialing
••••••••••••••••.•••••••.•• 56
Checking Audio
•••.•.•••••••••••••••.•.•••.• 57
TROUBLESHOOTING CORDLESS
TELEPHONES .............................. 58
Introduction ................................ 58
Getting Started ............................. 58
The 15-Second Operational Check ••••••••• 58
Analysis
Of Operational Tests •••••.••..••• 59
Fault Isolation .............................. 63
Troubleshooting Poor Performance .•••.••• 67
Testing Digitally Coded Cordless
Telephones ........... .................... 68
Other Cordless Telephone Schemes ••••.••. 69
BLOCK DIAGRAM ANALYSIS ••••••••••••••• 70
Norl-RF Testing ............................ 70
RF-Testing ................................. 73
Level Metering ............................. 75
Power Supply ............•............•..... 76
OPERATOR MAINTENANCE ••.••.•••••••••• 77
Periodic Meter Zero Adjustment •••••••••• 77
Fuse Replacement .......................... 77
SERVICING INFORMATION •••••••••••••••.• 78
Removal Of Top Cover ••..••••••••••••••••• 78
Calibration ................................. 78
Instrument Repair Service ••••••••••••••••• 83
Additional Servicing Information •.•••••••• 83
WARRANTY SERVICE INSTRUCTIONS
••••• 84
WARRANTY
.....•...•................•....... 85
CORDLESS TELEPHONE
FREQUENCY TABLE
••.••• inside rear cover

INTRODUCTION
The B
&.
K-Precision Model 1050 Telephone
Analyzer
is
a full
featured
test
instrument
for
testing, troubleshooting, and adjusting corded
telephones, cordless telephones, telephone
an-
swering machines,
automatic
dialers and most
other
telephone products. The
instrument
generates
virtually all signals needed for
tele-
phone product servicing. These signals include
de telephone line voltage,
20
Hz
ring signal,
dial tone, ringback, fixed 1 kHz audio, variable
100
Hz
to
10
kHz audio, and
rf
on
all
fre-
quencies assigned for cordless telephone
oper-
ation. The
instrument
also analyzes virtually
all signals
generated
by
telephone products.
These include
DTM
F and pulse dial
verifi-
cation, de levels, audio levels,
relative
rf
level,
rf
frequency error, and
FM
deviation.
Other
important
features
include
testing
of
telephone cords for short or open
circuit
paths, a variable
1.
5-10 V de power source,
and jacks to
accomodate
an oocilloocope or
frequency
counter
for
external
measurements.
CORDED
TELEPHONE FUNCTIONS
This
instrument
simulates
a telephone
ex-
change in
that
it
generates
a dial tone, rings
an on-hook telephone, stops ringing when
the
telephone is taken off-hook, links two
tele-
phones
together
for voice quality testing, and
operates
answering machines,
automatic
dialers, and
other
telephone products. When
the
analyzer is used in the dial mode
of
oper-
ation,
the
telephone
test
jacks
simulate the
voltage and
resistance
of
a telephone line. A
dial tone
identical
to
that
provided
by
the
telephone company's
is
supplied
at
the
test
jacks
as well as ringing signals (jack
#1
only),
ringback tones (jack
#2
only), and voice
com-
munication
between
the
test
jacks. A switch
reverses
the
polarity
of
the de voltage applied
to
the
first
telephone
test
jack
to allow
testing
of the
automatic
polarity
circuits
in
the
telephone.
When a telephone
is
plugged into the
first
telephone
test
jack, dialed numbers (from
either
a pulse or tone dial telephone)
are
decoded
and
displayed
by
the
analyzer. For
use with high speed dialers,
the
numbers
are
slowly released
in
the same order as dialed.
. 1
During the ring
test,
ring voltage can be
adjusted from
35
to 100 Vrms. This not only
tests
the ability
of
a telephone
to
ring but also
finds
the
threshold voltage of the telephone's
ringer circuit. For
intermittent
ringing prob-
lems and signal tracing,
the
analyzer's ring
generator
can be switched to a continuous ring
cycle (as opposed to
the
normal 2
to
2-1/2
seconds
on
and 3-1/2 to 4 seconds off).
When
the
analyzer
is switched to
the
conti-
nuity mode of operation, the telephone
test
jacks and handset continuity jacks
are
con-
nected
so
that
handset and telephone line
cords can be
tested
for
shorts
and breaks. The
polarity switch is used to verify
that
the cord
is
wired correctly.
CORDLESS TELEPHONE FUNCTIONS
The analyzer also includes many
features
for cordless telephone servicing. When used in
the
receive mode, the
instrument
serves as a
calibrated
test
receiver
for servicing
the
com-
panion base or
portable
transmitter.
The
tester
will show whether or not a signal
is
being
generated
by
the
transmitter
under
test.
Step
attenuators
at
the input
of
the
tester
permit
relative
rf
power
output
measurement. A
meter
measures
carrier
fre-
quency
error
and can be switched to measure
transmitter
modulation.
An
audio
output
is
available
at
an output
terminal
for connection
to
an oscilloocope, frequency counter, or
other
instrument. This
permits
convenient
meas-
urement
of
the guardtone frequency, for
ex-
ample. The audio
output
is
also applied to a
speaker,
permitting
voice quality and
other
listening
tests.
When used in the
transmit
mode
of
opera-
tion,
the
instrument
serves
as an
rf
signal
gen-
erator,
simulating the base or
portable
trans-
mitter
for servicing
the
companion
receiver.
A properly modulated
rf
output
from
the
tester
should
result
in an audible signal from
the
receiver
under
test
(go-no go test). Such a
signal also
permits
signal
tracing
throughout
the
receiver
under
test.
The
rf
output
level
is
variable,
permitting
relative
receiver
sensi-

INTRODUCTION
--------------------------------------------------------------------
tivity measurement. The rf output frequency
is calibrated, thus a measurement in the
re-
ceiver under test determines any carrier fre-
quency error. A built-in 1 kHz oscillator pro-
vides convenient
internal modulation and a
built-in variable frequency oscillator can be
used to span
the audio frequency and generate
guardtones. Two external modulation jacks
permit modulation by an audio generator or a
telephone (voice test). Internal and
external
modulation are independently selectable and
adjustable, and both may be used
simultane-
ously if desired. The built-in frequency er-
ror/modulation meter measures modulation or
error and the level meter measures a variety
of ac or de levels from input and output con-
nectors
on the front panel The oscilloscope
output jack
permits measurement of the
modulating
signal A frequency counter could
be connected for accurately setting the inter-
nal audio generator to the desired guardtone
or ring signal frequency.
The
tester operates on all radio frequencies
allocated for cordless telephone usage by the
FCC, including the 1.7 MHz, 46 M Hz, and
49 M Hz bands. Digital channel selection is
fast and easy. A phase locked loop and crystal
control provide stable frequency precision,
serving as a
standard for checking and re-
adjusting cordless telephone frequency gener-
ation circuits.
The frequency error/modulation
meter has
two ranges, 0 - 3 kHz and 0 - 10 kHz. The low
range provides good resolution for
carrier fre-
quency error measurement and low modulation
and the high range permits measurement
of
fully modulated signals. Also, when the 0 -
3 kHz range and
rf error mode are selected, a
filter is enabled that removes the effect of
guardtone modulation. This allows frequency
error measurements to be made without dis-
abling the guardtone signal in the unit under
test. The built-in 1 kHz oscillator output is
also available
at an output jack for external
use. It is convenient for modulating the rf
carrier of a cordless telephone transmitter
under test.
The guardtone
filter can be switched in or
out,
permitting measurement of guardtone
modulation when desired, and
rejecting guard-
tone and high frequency noise (above 3 kHz)
from the speaker for voice listening
tests.
2
LEVEL METER FUNCTIONS
The level meter measures a variety of ac
and de signal levels. When the audio output
mode is selected, three metering ranges are
available. When any of the other modes are
selected two metering ranges are available.
All
ac measurements can be made in either
volts or dBm.
When the
meter is used to measure tele-
phone line audio, it shows the actual signal
level
that is present when operating the tele-
phone on a telephone line. The meter may be
used to measure both incoming and outgoing
audio as well as dailing tone signal
level
The meter may also be used to measure the
level of signals fed to the audio input jacks.
This is a convenient way to
set externally gen-
erated signal levels for use as a modulation
source when transmitting.
When the external
modulation level control is turned off, the
audio input telephone jack is disabled and the
input impedance of
the BNC jack is switched
from 600 Q to 1 M
Sf. This allows the audio
input BNC to be used as a probe input and
the
meter to be used as a general purpose ac
voltmeter.
When one of the audio output pushbuttons is
selected, the meter shows the output voltage
of the
internal signal generator. This allows
you to
set the level of the internally generated
modulation signal without the use of an oscil-
loscope or ac voltmeter.
The meter also may be used to measure the
level of a signal applied to the demodulator
probe jack. This permits
the use of a demodu-
lator probe touched to an antenna of any cord-
less telephone to measure relative transmitter
power.
When one
of the de volts out pushbuttons is
selected,
the meter shows the de voltage that
is available at the de voltage output jacks.
This allows you to
set the de voltage without
the use of an external voltmeter.
The load function of the meter allows you
to measure
relative signal strength of 1.7 MHz
band rf transmitted from the base unit. This
eliminates the need for special circuits to
connect
the rf signal to a signal level meter.

------------------------------------------
FEATURES
TELEPHONE POWER SOURCE:
Simulates standard telephone line. When a
telephone is plugged into the analyzer, a de
voltage is applied to
the line through a re-
sistance that simulates line resistance. Off-
hook
detection circuit in analyzer simulates
conditions on standard telephone line; e.g.,
ring signal
is automatically cancelled when
telephone goes
off hook.
CORD TEST:
Checks for shorts, open conductors, and bad
connectors. Simply plug
in a telephone cord
and
the indicator(s) lights if the cord is good.
RING TEST:
20 Hz ringing signal simulates a telephone ex-
change. Ringing voltage is variable from 35 to
100 Vrms. Switchable to continuous ringing
for signal
tracing and intermittent problems.
DIAL TEST:
Decodes dialing signals for both pulse and tone
dial telephones and indicates number dialed.
Holds up to
16 digits in memory for slow re-
lease. Slow sequence releases two num-
bers/second
so that even rapidly dialed num-
bers can be easily read. Can also test Redial
and Memory dial functions
of a telephone. For
tone dial telephones, an indicator lights when
level is sufficient. ·
VOICE LEVEL TEST:
Indicator lights when voice level meets or ex-
ceeds minimum acceptable level
SECOND TELEPHONE CAPABILITY:
Permits voice quality of telephone to be
checked when a second telephone is
available. Also
permits testing of answering
machines.
POLARITY TEST:
Tests automatic polarity circuit in telephone.
Assures
that telephone will operate if polarity
of telephone line is reversed.
TELEPHONE UGHTING:
Power is provided at the phone jack to check
"Princess" is a registered trademark of AT&T
3
the light in a "Princess" type telephone (or any
other telephone with a light in it).
LINE SCOPE JACK:
An output jack on the front panel allows an
oscilloscope to be used to monitor dialing
pulses and voice audio applied to telephone
test jacks.
PRECISION DIAL TONE AND RINGBACK
SIGNAL:
Simulates standard telephone company dial
tone and ringback signals.
FREQUENCY RESPONSE TEST:
Using the built-in frequency generator and
audio metering circuits,
it is easy to test
frequency response on corded or cordless
telephones.
PRE-PROGRAMMED FREQUENCIES:
All frequencies that are allocated for cordless
telephone usage
are programmed into the
tester. Using the chart at the back of this
manual, you can select any frequency used for
cordless telephone operation.
CHANNEL NUMBER DISPLAYED:
Channel display indicates the channel that is
presently selected (0 through 99). Each
cordless telephone frequency is assigned
to a
specific channel or channels.
RELATIVE TRANSMITTER POWER
MEASUREMENTS:
Three step attenuator allows measurement of
relative rf power of cordless telephone
transmitters.
L 7 MHz RF LEVEL METERING:
Relative rf power of a 1. 7 MHz band cordless
telephone base
t.mit transmitter can be
measured. Analyzer simulates standard power
line load and couples
rf signal to internal
meter.
RHLATIVE RECEIVER SENSITIVrrY
MEASUREMENTS:
Three step and variable attenuators allow

FEATURFS
measurement
of
relative
rf
sensitivity
of
cordless telephone receivers. Attenuation
is
variable from 0 to approximately 110
dB.
INTERNALLY
GENERATED
VARIABLE
FREQUENCY
SIGNAL:
Built-in
generator
provides 100 Hz to
10
kHz
signal for use
in
modulating
rf
signal or for
external
use
in
signal tracing. When using
the
Analyzer as a
transmitter,
the
generator
may
be
set
to ring or guardtone frequency.
INTERNALLY
GENERATED
1kHz
SIGNAL:
Bull
t-in
1
kHz
generator
provides audio signal
for use in modulation
of
rf
signaL
MODULATION LEVEL CONTROLS:
Front panel controls allow you to adjust
the
level
of
the external,
1
kHz, and variable
fre-
quency modulating signals independently,
can
be used simultaneously if desired.
THREE
CHOICFS
OF
MODULATING
SIGNALS:
RF Output controls allow you to choose
ex-
ternal
modulating signal,
internal
modulating
signal, or both
internal
and
external
modu-
lating
signals.
TWO
TYPFS
OF MODULATING SIGNAL
INPUT
JACKS:
BNC or modular telephone jack allows use
of
signal
generator
or telephone as modulating
signal source.
CHOICE
OF
RF
INPUT MODE
OF
OPERATION:
Frequency
error
mode allows you to check
cordless telephone
transmitter
carrier
fre-
quency
error
in kHz. Modulation deviation
mode allows you to check deviation
of
cordless
telephone
carrier
signal caused
by
modulating
signaL
SCOPE
OUT
JACK:
An
output
jack
on
the front panel provides the
demodulated signal for use with an oscillo-
scope or frequency counter.
DUAL
SCALE
DEVIATION METER:
Dual
scale
meter
allows you
to
read
frequency
error
or deviation from
0
to
3
kHz or from
0
to
10kHz.
4
BUU.T-IN
SPEAKER
AND AUDIO
AMPLIFIER:
Built-in speaker allows you to listen
to
demod-
ulated
signaL Volume
level
is adjustable using
the
Speaker Volume controL
SELECTABLE
GUARDTONE
REJECT:
Reject
mode connects a low pass
filter
which
eliminates
any signals above 3.5 kHz from the
demodulated audio. Pass mode disconnects
the
low pass
filter.
OEM
ODULATOR
PROBE
MEASUREMENTS:
When
the
demodulator probe function of
the
meter
is
selected
and a demodulator probe is
connected to
the
demodulator probe jack,
the
probe may be touched to the
antenna
of
any
cordless telephone for a
relative
measurement
of
the
output
power
of
the
cordless telephone's
transmitter.
Input for demodulator probe may
also be used for signal
tracing
of
a cordless
telephone
rf
signaL
BUILT-IN
DC
POWER
SUPPLY:
Jacks
provide variable
1.
5 to
10
Volt de
voltage for powering a cordless telephone
in
lieu
of
batteries
or
defective
power supply.
May also be used to
test
effect
of
varying
battery
voltage. Built-in
metering
with two
ranges allows
setting
of
output
voltage
without
the
use
of
an
external
voltmeter.
LINE AUDIO MEASUREMENTS:
Using
the
level
meter,
it is possible
to
measure the level of the audio signal
at
telephone
test
jack
#2.
AUDIO
INPUT
MEASUREMENTS:
The level
meter
may also be used to
measure
the
level
of
audio applied to the audio input
jacks.
This
allows
the
level
of
the
externally
generated
signal to be
set
without
the
use
of
an
external
meter.
AUDIO
OUTPUT
MEASUREMENTS:
Using
the
level
meter,
it
is
also possible
to
measure the level
of
the
internally
generated
variable frequency signaL
This
allows you
to
set
the
level
of
the signal without
the
use
of
an
external
meter.

SPECIFICATIONS
CORDLESS TELEPHONE TESTER
TRANSMlf
AND RECEIVE FREQUENCIES
All
assigned
cordless
telephone
fre-
quencies
in
ranges
of
1.
6
to
1.
8 MHz,
46
to
47 MHz, and 49
to
50
MHz (see inside
rear
cover).
TRANSM:rrTER
RF
Generating
Systems:
Crystal-controlled
phase-locked
loops.
Frequency
Selection:
2-Digit
dedicated
channel
selectio~
Frequency
Display:
2-Digit
channel
number
indicatio~
RF
Temperature
Stability:
± 0.001% (10 ppm).
',
RF
Output
Level:
.0 dB
into
50
g.,
±3
dB;
continuously
variable
attenuation
of
0
to
20
dB,
uncali
bra
ted.
Attenuation
Steps:
Low Band:
20
dB,
30
dB,
and
40
dB,
±1
dB.
High Band:
20
dB,
30
dB
±1dB,
40
dB
+0
dB/-5
dB.
Modulation:
F.M. ·
Modulation
Bandwidth:
600 Hz
to
7
kHz
±3
dB, 1 kHz
ref.
400 Hz
to
10 kHz ±
4.
5 dB, 1 kHz
ref.
Modulation
Source:
Three
sources
(for
use
separately
or
simultaneously):
internal
1 kHz
generator;
internal
variable
audio
generator;
external
source
(AUDIO
IN
jacks).
Modulation
Voltage:
0.5 Vrms (1.4 V p-p)
into
AUDIO
IN
jack
·(10 Vrms
absolute
max).
Deviation:
0
to
±10
kHz, adjustable.
5
Deviation
Display:
Analog
meter
accuracy;
0
to
3 kHz
range,
±10%
of
full
scale,
0
to
10
kHz
range,
±5%
of
full
scale.
Deviation
Monitoring:
Connection
for
external
oscilloscope.
1kHz
GENERATOR
Use:
Generates
frequency
modulation
of
internal
transmitter,
if
selected.
Frequency:
1kHz
±1%.
Distortion:
0.8%
max
•
RECEIVER
Frequency
Selection:
Same
method
as
for
transmitter.
Frequency
of
Received
RF:
Frequency
error
(compared
to
selected
channel
frequency)
displayed on
analog
meter,
0
to
3kHz
and 0
to
10
kHz ranges, 8 kHz max.
0
to
3 kHz
Range:
±5%
of
full
scale,
±0.25 kHz.
0
to
10
kHz Range:
±5%
of
full
scale.
Modulation
Bandwidth:
High Band: 400 Hz
to
3 kHz
±1
dB; 3
kHz
to
7
kHz
+1
dB/-4
dB, 1 kHz
ref.
Low Band: 400 Hz
to
3kHz
+1
dB/-4
dB,
1kHz
ref.
Modulation
of
Received
RF:
Displayed on
deviation
meter,
0
to
3kHz
and
0
to
10
kHz
ranges,
7kHz
max.
±0.3
kHz
for
0
to
3 kHz
deviation
(high
and
low band).

SPECIFICATIONS
±0.3 kHz
±10%
for
3kHz
to
7kHz
deviation (high band only).
Guardtone
Rejection:
Filter
and
switch
allow
observation
or
rejection
of
guardtone
modulation.
3 kHz low pass
filter,
nominal
20
dB/octave.
Deviation Monitoring:
Connection for
external
oscilloscope.
Audio Monitoring:
Connection for
external
oscilloscope.
Built-in
speaker
with volume
control
and
ON/OFF switch.
CORDED TELEPHONE TESTER
GENERAL
Telephone Line Simulation:
Single
or
two telephone
operation.
DC Line Voltage:
52
V ±15%,
1.
5 kn
source
impedance.
Current:
28
rnA
nominal (off hook).
Polarity
Test
Switch:
Dial Mode:
reverses
telephone line
polarity.
Continuity Mode: Checks for
inverted
wire
order
in telephone and
handset
cords.
Voice/Dial
Level
Indicator:
Illuminates
for
levels
greater
than
0.1
V.
Cord
Tests:
Tests
both 2-wire and 4-wire
telephone
line and
handset
modular cords
for
shorts
or
continuity.
Tests
for both
normal
and
inverted
wire order.
Reset:
When pressed; shuts
off
ring,
clears
display, and removes
dial
tone.
RING SOURCE
Frequency:
20Hz.
Voltage:
Adjustable from
35
to
100 Vrms
±10%
with
1
ringer
equivalent
load
Off-Hook
Detection:
DC line
voltage
less
than
25
volts
inhibits
ring.
Ring Cycle:
2 seconds on, 4 seconds
off,
or continuous
ring with RING LEVEL
control
pulled out.
6
AUTOMATIC NUMBER IDENTIFICATION
DTMF
(Dual
Tone Multiple Frequency):
Tolerance:
Accepts
tone within ±1.5%
of
nominaL
Tone
Duration
For
Identification:
50
msec minimum.
lnterdigit
Time:
50
msec minimum.
Amplitude Response (Composite Tone):
0.25 V(-10 dBm).
PULSE DETECTION:
Rate:
8
to
20
pulses/sec.
Break
Time:
30
msec minimum.
Make
Time:
15
msec minimum.
lnterdigit
Time:
315 msec minimum.
Recognition
Time
(end
of
digit):
100 msec minimum.
Manual Dialing (pulse
type
and
DTM
F):
Detects
and decodes number dialed by
telephone under
test.
AUTOMATIC DIALER AND REDIAL
Pulse
Type:
Verifies numbers dialed.
DTMF:
Uses
a
delay
circuit
to
verify
numbers
dialed with
rates
up
to
10
digits/second.
Digits
are
displayed
at
a
rate
of
2/second
for easy
verification.

DIALED NUMBER DISPLAY:
Single
0.43" 7
segment
LED.
Delay
feature
for
high
speed
dialer.
Digit
flashes
to
mark
display
update.
TONE
CHARACTERISTICS
Dial Tone:
352 Hz
and
440 Hz nominaL
SPECIFICATIONS
---
·
----------------
Dial Tone
Accuracy:
±2%.
Dial Tone Amplitude(s):
0.05 V nominaL
Ringback Tone:
440 Hz
and
20
Hz.
Ringback Tone Amplitude:
0.
026 V nominaL
AUXU.IARY
CIRCUIT
SPECIFICATIONS
AUDIO
GENERATOR
Frequency
Range:
100 Hz
to
10 kHz,
continuously
variable.
Frequency
Accuracy:
Depends
on
accuracy
of
external
frequency
counter.
Frequency
Stability:
±0.1%
±1
Hz
per
15
minute
interval
(after
15 min.
warm-up).
Amplitude
Flatness
Within
±0.5 dB, 100 Hz
to
10kHz.
Internal
Use:
Generates
frequency
modulation
for
deviation
level
adjustments,
for
either
voice
information
or
guard
tones.
·
Level
continuously
variable.
Can
be
monitored
by
external
counter
or
oscilloscope
as
well
as
by
Level
Meter.
External
Use:
Generates
0
to
1 Vrms
(into
600$1),
variable.
Amplitude
can
be
monitored
by
Level
Meter.
Output
Impedance:
600
ohms
± 10%.
Distortion:
1% max.
at
1kHz,
3%
max.
for
1kHz
to
10 kHz,
6%
max.
for
100
to
1000 Hz.
LEVEL
METER
Fmction
Selection:
.
Push-button
switches
(interlocked).
Fmction
Measured:
Audio
Output:
0-30mV, 0-100
rnV,
and
0-1 V
(rms).
7
Audio Input: 0-1 V
and
0-10 V (rms).
Telephone
Line Audio: 0-1
and
0-10 V (rms).
DCV Supply
Output:
1.5-5 V
and
1.5-10
V.
RF
Demodulator
Probe
Input: 0-1
and
0-10
v.
Internal
Dummy
Load: 0-1
and
0-10 V (rms).
Accuracy:
±5%
of
full
scale.
Input
Impedance:
1
MS1
±10%
(with
EXT MOD
LEVEL-0FF).
Audio
Frequency
Response:
45
Hz
to
20
kHz
±3
dB, 1
kHz
ref.
dBm
Scales:
Provided
for
use in AC
functions
(0
dBm =
1mW
across
600
n.).
DC
VOLTS
OUTPUT
Voltage
Range:
1.5
to
10
V,
continuously
variable.
Can
be
monitored
by
Level
Meter.
Output
Current:
0
to
150 rnA,
overload
current
limited.
Loe.d
Regulation:
0.
25%
or
25
mV max.
change
of
voltage
with
current
variation
within
rated
limits.
Line
Regulation:
0.5%
or
50
rnV
max.
change
of
voltage
with ±10%
change
of
line
voltage
within
rated
limits

SPECIFICATIONS
:bol.ation:
Both
terminals
isolated
from
earth
ground,
200 V max. allowed
float
voltage.
120
VAC JACK
Use:
Supplies power for a cordless
telephone
base
station
and is
path
for
its
rf
output.
Measures
both
A
&.
B
rf
modes.
Output Current:
1
I
4 A max. (fused).
Isolation:
None.
GENERAL
Connectors
Telephone: modular RJ-11
style
(4
contact).
DCV
out:
banana
(5-way binding posts).
RF and AF:
BN
C.
Digital
Display:
2+1
7-segment
LED digits, 0.43" high.
Operating
Temperature:
0°
to
40°C
(32°
to
104°F).
Power
Required:
105
to
132
V,
60Hz,
80
VA.
Dimensions:
(H
X
W
X
D)19
X
45
X
29
em
(7.3
X
17.8
X
11.6")
8
Weight:
9.5 kg.
(21
lbs.)
OPTIONAL ACCESSORIES
B
&
K-Precision
Model
PR-32
demodulator
probe.
Cobra Model TA-302 wired
to
modular
plug
telephone
adapter.
Cobra Model TA-305 4-pin
to
modular
plug
telephone
adapter.
Cobra Model WP-142
standard
telephone.
SUPPLIED ACCESSORIES
Model CC-53 Coupling Coil.
Instruction
ManuaL
Schematic
Diagram and
Parts
List.

DEFINmONS OF TERMS
L 7 M Hz Band Any of several specific carrier
frequencies of approximately 1.7 MHz. The
base-to-portable link of all earlier cordless
telephones operates in the 1.7 MHz band.
46 MHz
Band Any of several specific carrier
frequencies of approximately 46 MHz. The
base-to-portable link of all later cordless tele-
phones operates in the 46 MHz band.
49 MHz Band Any of several specific carrier
frequencies of approximately 49 MHz. The
portable-to-base link of all cordless telephones
operates in the 49 MHz band.
Carrier Frequency. The center frequency of a
radio signal
that can be modulated in fre-
quency, amplitude, or other ways to transmit
audio, images, or other electronic signals.
A(Delta) F. The
amount of offset (measured in
kHz} from a
specified carrier frequency.
Demodulation.
Separating the modulating sig-
nal from the carrier frequency. The circuit
used for demodulation in cordless telephone
receivers is usually called a "discriminator".
Deviation. The amount of frequency swing
from
the carrier frequency in FM modu-
lation. A carrier frequency of 49.700 MHz
with
±10 kHz deviation swings from
49.690 MHz
to 49.710 MHz. The amount of
deviation is determined by the amplitude of
the modulating signaL FCC regulations spec-
ify the maximum deviation permissible for
cordless telephone service.
Dial Tone. Tone generated by the telephone
company to indicate that your telephone is off
hook and ready to diaL
DTMF
(dual tone multiple frequency). Pairs of
tones generated by telephone. Each digit is a
different pair of tones. Sometimes referred to
as "Touch Tone".
Discriminator. An FM demodulation circuit.
"Touch Tone" is a registered trademark of AT&T.
9
EPROM (Erasable Programmable Read Only
Memory). A
digital logic device that stores
bits of digital information (either a logic high
or logic low). This particular memory device
retains information even when power is re-
moved from the chip. It is possible to erase
and re-program this device using hardware
that is outside of the device in which the
memory is used.
FCC (Federal CommWlieations Commision}.
Governs radio licensing and assigns radio
fre-
quencies for private, commercial, and gov-
ernmental usage. Also enforces existing radio
and
communication laws. Cordless telephone
carrier frequency assignment, maximum
transmitter power, maximum deviation, etc.
are controlled by FCC regulations.
FM (Frequency Modulation). The encoding
(modulation)
of a carrier signal by causing fre-
quency changes. The amount of frequency
change depends on the amplitude of the modu-
lating signaL
Guardtone.
In cordless telephone operation, a
5
to 7 kHz audio signal that modulates the
portable transmitter carrier signal when in the
talk mode. The guardtone is detected in the
base receiver to initiate "off hook" circuit
conditions. A guardtone filter prevents the 5
to 7 kHz tone from being applied to the tele-
phone line along with the 300 -3000 Hz voice
audio.
Several guardtone frequencies are used
to help prevent unauthorized capture of a
telephone line by nearby cordless telephones
operating on the same carrier frequency.
1-F
(Intermediate Frequency). A frequency
within a receiver that is lower than the car-
rier, typically 10.7 MHz (1st i-f) and 45 5 kHz
(2nd i-f).
An i-f signal is produced by a mixer.
Mixer. A
circuit with two rf input signals
(typically,
the received rf carrier and a local
oscillator signal), whose output signal fre-
quency equals the difference between the two
input
frequencies.

DEFINITIONS OF TERMS
Modulation. A change in the carrier signal
caused by voice, audio tones, or other elec-
tronic signals. For cordless telephones, FM
modulation is used.
Off-Hook. Condition when telephone is taken
out of the cradle. as if engaged in a telephone
call or dialing.
On-Hook. Condition of telephone when in the
hung up position. Telephone is idle when on-
hook.
Phase Locked Loop. A frequency generator
comprised of a reference frequency oscillator,
a VCO, and a feedback loop including a pro-
grammable digital divider and an error de-
tector. By selecting different divider ratios in
the programmable digital divider, a phase
locked loop can operate on many different
frequencies with stability and accuracy that
10
approaches that of its single crystal-controlled
reference oscillator.
Ring SignaL On a telephone line, a 20 Hz, 80
to 130 Vrms signal generated by telephone
company to ring telephone. Standard signal is
on for 2
to 2-1/2 seconds, off for 3-1/2 to 4
seconds.
On the base-to-portable link of a
cordless
telephone, a specific audio tone (typi-
cally in the 700 Hz to 1500 Hz range) used to
modulate the rf carrier, concurrent with the
20 Hz ring signal on the telephone line.
Ringback SignaL Signal generated by tele-
phone company to indicate that the telephone
being called is ringing. Standard signal is a
440
Hz signal chopped at 20 Hz and on for 2 to
2-1/2 seconds, off for 3-1/2 to 4 seconds.
VCO (Voltage Controlled Oscillator). Oscil-
lator whose frequency is dependent upon the
applied voltage.

CONTROLS AND INDICATORS
(Refer
To Fig. 1.)
1.
POWER Switch. Turns
tester
ON
and
OFF.
2.
3.
4.
LEVEL
Meter.
Used in
conjunction
with
meter
range/function
switch
(item
39).
Shows
level
of
LINE AUDIO, AUDIO
IN-
PUT, AUDIO OUTPUT, DEMOD. PROBE,
DCV OUT, and
LOAn
Seven
scales
are
provided; 0
to
10 Volts, 0
to
5 Volts, 0
to
30
m
V,
-infinity
to
-28
dBm,
-infinity
to
22
dBm,
-infinity
to
2 dBm,
and
-40
to
-18
dBm. The 0
to
10
scale
is used when
range
selected
is 100 mV, 1
V,
or
10
V;
0
to
5
scale
when
the
5 V DCV
OUT
range
and
function
are
selected;
0
to
30 mV
scale
when
the
30 mV AUDIO
OUTPUT
range
and
function
are
selected;
-infinty
to
22
dBm
scale
when
the
range
selected
is 22 dBm;
-infinity
to
2 dBm
scale
when
the
2 dBm AUDIO
OUTPUT
range
and
function
are
selected;
and
the
-40
to
-18
dBm
scale
when
the
-18
dBm AUDIO
OUTPUT
range
and
function
are
se-
lected.
AUDIO
OUTPUT
FREQUENCY
Con-
trol
Controls
frequency
of
internally
generated
audio signaL
Frequency
is
variable
from
100 Hz
to
10
kHz. This
audio is
available
at
the
AUDIO
OUT
jack
as
long
as
the
AUDIO
OUT
LEVEL
control
is
turned
on.
AUX LINE
Indicator.
During
cord
test,
indicates
condition
of
two
auxiliary
wires
in
detachable
cord. When
lighted,
conti-
nuity
is
indicated.
5. SINGLE
UNE
Indicator.
During
cord
test,
indicates
condition
of
two
tele-
phone wires in
detachable
cord. When
lighted,
continuity
is
indicated.
For
most
telephones
only
these
two
tele-
phone wires
are
used
The
two
auxiliary
wires
are
used
to
carry
power
to
a
night
light
in a
telephone.
6.
VOICE/SIGNAL LEVEL
Indicator.
Lights
when
dialing
tones
are
above
minimum
11
7.
8.
9.
10.
11.
leveL Lights on voice
peaks
when
above
minimum
required
leveL
DIALED NUMBER DISPLAY. Single
dig-
it
display.
Indicates
telephone
number
actually
dialed. Digit is
blanked
momen-
tarily
between
digits.
CHANNEL
Indicator.
Two
digit
dis-
play.
Indicates
channel
in use. See
in-
side
rear
cover
for
frequency
listing
of
each
channeL
RING
Button.
Starts
ringing
telephone
at
voltage
set
by RINGER LEVEL
con-
troL Ringing
continues
until
telephone
is
picked up
or
RESET
button
is
pressed.
RESET
Button.
Resets
DIALED NUM-
BER DISPLAY
circuitry
and
causes
a "0"
to
be
displayed
Also
turns
off
dial
tone
and
cancels
ring
signaL
t
UP
Controls.
Controls
channel
selec-
tion.
Right
button
causes
ones
digit
to
count
up when
pressed.
Left
button
causes
tens
digit
to
count
up when
pressed.
Momentarily
pressing
button
will
cause
one
count
up, holding
button
will
cause
continuous
counting
up.
Channel
is
locked
in when
the
button
is
released
When
the
ones
digit
counts
up
past
9,
it
does
not
cause
the
tens
digit
to
count
up (i.e. when
counting
up
from
channel
19,
if
only
the
right
fUP
button
is
pressed,
the
next
channel
will
be
10,
not
20).
12. CHAN. RESET
Control
Resets
channel
to
"00" when
pressed.
13. METER RANGE
Switch.
Selects
AF/MOD
meter
range.
When
3kHz
is
selected,
lower
/l.F/MOD
meter
scale
is
used
and
maximum
reading
is 3 kHz.
When 10
kHz
is
selected,
upper
scale
is
used
and
maximum
reading
is 10 kHz.
14.
INPUT
GUARDTONE Switch.
In
RF
IN-
PUT
mode~
when
switch
is in
the
PASS

CONTROLS AND INDICATORS
position,
guardtone
and
other
signals
above
3kHz
are
passed to
the
6F/MOD
meter,
speaker,
and SCOPE OUT jack.
In
RF
INPUT mode, when
switch
is in
the
REJ
position,
guardtone
and
other
signals
above 3 kHz
are
filtered
out
and
are
not
fed to
the
l1F/MOD
meter,
speaker,
and
SCOPE OUT jack.
15.
6F/MOD
Meter.
Shows
amount
of
car-
rier
frequency
error
or
carrier
deviation
in kHz. Two
scales
are
provided, 0 to
3 kHz and 0
to
10
kHz.
16. 1 kHz MOD LEVEL
Control
Controls
level
of
1 kHz
internally
generated
mod-
ulating
signal when INT
or
EXT & INT
mode
of
RF OUTPUT
are
selected.
When
this
control
is
turned
fully
coun-
terclockwise,
the 1 kHz signal
is
turned
off.
17. EXT MOD LEVEL
Control
Controls
level
of
externally
applied modulating
signal when EXT
or
EXT
&::
INT mode
of
RF
OUTPUT is
selected.
Full
counter-
clockwise
rotation
disables AUDIO
IN
telephone
jack
and
terminates
AUDIO
IN
BNC
jack
into
1
M
n.
On position enables
AUDIO
IN
telephone
jack
and
terminates
BNC and
telephone
jack
into 600
n.
18.
RF
OUTPUT
MOD
Controls.
Selects
output
mode. The
instrument
acts
as
a
cordless
telephone
transmitter
when one
of
the
three
output
modes is
selected.
EXT: When this
button
is engaged,
carrier
is
modulated by
external
signal applied to
the
AUDIO
IN
jacks.
INT: When this
button
is engaged,
carrier
is modulated by
internally
generated
1 kHz
and/or
variable
frequency
sine waves.
EXT
&::
INT: When this
button
is
engaged,
carrier
is modulated by
both
an
external
signal
(applied
to
the
AUDIO
IN
jacks)
and
the
inter-
nally
genera
ted signal(s).
19.
RF
INPUT Controls.
Selects
input
mode. The
tester
acts
as
a
cordless
12
telephone
receiver
when one
of
the
two
input
modes is
selected.
RF
f1
F: When this
button
is pushed
in,
6F/MOD
meter
reads
amount
of·
carrier
frequency
error
(6F).
MOD (DEV): When this
button
is
pushed in, f1F/MOD
meter
reads
amount
of
carrier
signal
deviation
caused
by
modulating signaL
20. RF IN/OUT
Jack.
Connector
for input
and
output
RF.
21. INPUT/OUTPUT ATTENuation (dB).
Three
switches
select
attenuation
for
both
input and
output
rf
signals. Provide
20
dB,
30
dB,
or
40
dB
steps
of
attenu-
ation.
Can be used
together
to give
at-
tenuation
steps
from 0 to
90
dB. The
OUTPUT LEVEL.
control
can be used in
conjuction
with
these
switches
to
provide
up
to
110 dB
total
output
attenuation.
22.
RF
OUTPUT LEVEL
Control
Controls
output
level
of
RF signaL Range
of
at-
tenuation
is
approximately
0
to
20
dB.
23. SCOPE OUT
Jack.
Supplies
demodulated
output
for viewing on oscilloscope when
in
receive
mode (when one
of
the
RF
IN-
PUT
modes has
been
selected).
In
transmit
mode (when one
of
the
RF
OUTPUT modes has
been
selected)
signal
that
is being used to
modulate
carrier
is
supplied. Also
permits
measurement
of
signal
using a
frequency
counter.
24. SPEAKER VOLUME
Control
Controls
volume
of
audio
output
at
speaker
.
Complete
counterclockwise
rotation
to
OFF position
disconnects
speaker.
25. DIAL MODE/CONT. (Continuity)
But-
toiL Controls mode
of
PHONE TEST
JACKS. When this
button
is engaged,
the
jacks
are
connected
for
cord
conti-
nuity
testing.
When
this
button
is
disen-
gaged, the
jacks
are
connected
for
tele-
phone
testing.
26. POLARITY NORMAL/REVERSE
But-
toiL When
the
analyzer
is in DIAL
MODE
of
operation,
button
reverses
po-

CONTROlS
AND INDICATORS
15 14 13 12
11
8
10
9
7 6 5 4 3 2
1
39
Fig. L Controls
And
Indicators.
13