Telex ENG-4 User manual

= Telex
Operating
Instructions
Professional Wireless
Microphone System
ENG-4
WT-400
TELEX.

INTRODUCTION
WHAT IS A WIRELESS MICROPHONE SYSTEM?
Microphone: This is an electro-acoustic
transducer which responds to sound waves
and deliver essentially equivalent electrical
waves. These electrical waves are sent to
the belt transmitter or handheld unit.
Transmitter: The transmitter generates and
amplifies an RF (Radio Frequency) carrier
signal, modulates this carrier with the
microphone signal, and radiates the modu-
lated RF carrier.
SIGNAL
MICROPHONE TRANSMITTER
Figu
RF CARRIER
Receiver: The FM VHF receiver is tuned to
the frequency of the transmitter. The
receiver picks up the radiated RF signal
from the transmitter through the antenna
and converts the RF signal into audio vol-
tages for use with PA, Line, Network, etc.
The receiver frequency must be matched to
the transmitter frequency.
(CUSTOMER SUPPLIED)
ae eae eS
|
|
AUDIO |
MIXER | SPEAKER
| |
LAMPLIFIER | |
i
|
|
|
|
FM
RECEIVER
are |
rel
Block Diagram of Typical Wireless Microphone System
WHAT FREQUENCY BAND
DOES THE TELEX SYSTEM OPERATE IN?
The Telex ENG-4 System features dual
channel, crystal controlled transmitters and
four channel receivers operating in the
VHF Band between 150-216 MHz. There
are 10 standard frequencies available.
Your system operates on a fixed frequency
which can be computer selected to provide
"interference free" operation. Up to seven
systems can be operated in a single location
simultaneously, without intermodulation.

OFTEN ASKED QUESTIONS
Question: Can more than one microphone
be used simultaneously?
ae Yes, but never on the same fre-
quency. You will need to have different fre-
quencies for every receiver/transmitter
combination. All units are factory set for
specific frequencies.
Ohoestion: Is the system more sensitive in
any one particular direction?
Aga No, the transmitter’s antenna
radiates equally in all directions, but the sig-
nal is attenuated by your body, walls or
other surrounding objects. The receiving an-
tenna is essentially sensitive in all directions
as well, except when using a directional an-
tenna.
Kestim: Can the receiver receive other
transmissions when the transmitter is turned
off?
Ay Yes it can. The Telex ENG-4 sys-
tem operates in VHF band between 150-
216 MHz. However, it is not susceptible to
radio wave skip, CB’ers or standard FM
radio transmissions.
29.
The frequency on which your system
operates can be computer selected for least
interference, but there is no such thing as a
100% clear channel all the time, anywhere
in the U.S.A., forever!
If the system is going to be used in a per-
manent fixed location, the system should
operate interference free until such a time
or date when someone else begins using the
same frequency.
If the system is going to be moving among
various locations, you will inevitably run
into occasional frequency conflicts.
In either case, when you’re not using the
wireless microphone, turn the gain down on
your audio mixer, just as you would a wired
microphone. If a mixer control is not avail-
able, turn the receiver off when the trans-
mitter is not in use. This will prevent the
reception of undesired signals.
If a mixer control is not available and the
system must be left on, the transmitter
should be left on to prevent the receiver
from picking up outside interference.

ENG-4
TECHNICAL
INFORMATION
General
Description:
A
fully
transportable
Features:
Small
size,
light
weight
and
is
self
VHF
FM
receiver
ideally
suited
for
electronic
contained.
news gathering, film or sound recording, or
other such activities.
Controls and Connections (Front Panel):
Rotary
Function
Switch/Meter
................ecceeeeeeenes
4-position
rotary
switch
with
meter.
Position
“OPE
ore
cone
came
recto
ce
mero
ese
Non-functional,
no
current
drain.
SHEE
EE
Ll
EE
T
eked
eiaponce
nie
paceuatoate
toveseansieeee
Built
in
meter
monitors
audio
output.
PG
SETTER
pean
ore
r
n
E
vant
Savon
atore
E
A
A
tency
ons
Built
in
meter
monitors
RF
received.
Position
-BAT
Pisses
estas
ve
paws
suienes
nacre
Built
in
meter
monitors
battery
voltage.
SVE
MOTILO
zeant
ENEN
ANEO
E
AIEEE
Adjusts
volume
to
headphone
output
jack.
Antenna
dack:
ausecsai
asas
BNC
jack
(supplied
with
flexible
antenna
for
frequencies
installed).
PQS
VDO
JACE
rea
TEE
ET
EE
EEE
T
NEEE
EAN
E
ONTAS
For
external
power
input.
Accepts 9 to 28 VDC, center pin is positive.
RER
Connector
wii
smorord
enva
For
MIC
or
LINE
level
output
(selectable
via
MIC/LINE
Switch).
Line
Output:
-ese
tni
esas
EE
A
E
a
E
EEE
For
600
ohm
balanced
line
output.
Mic
Level
Output
200
ohm
balanced
mic
level
output
(adjustable
via
Mic
Level
Control).
Controls (Rear Panel):
EERE
N
T
E
N
OREN
E
E
EE
O.
Controls
mic
level
output
to
front
panel
XLR
Connector.
Screwdriver
adjustable,
rotary
type
ENED) MIC SWI areen CENNAIS Slide switch that selects LINE or MIC level output for
front panel XLR connector. Screwdriver adjustable.
Compandor IN/OUT esr eaey E ea Slide switch that controls compandor operation.
Must be set to match transmitter operation. Screwdriver adjustable.
Channel A/B/C/D i reireroiuscirecaianin RF Channel (operating frequency) selection. Must be set
to match transmitter channel or frequency. Screwdriver adjustable, rotary type.
Battery, Relegem ori iE eNi atic rA DE EA EATE Squeeze to release slide locks. Internal battery
holder pops up through top of case.
ENG-4 Specifications:
ES e VAE EE iat E E T E P OER T E E r EO E Single conversion superheterodyne.
THERE TIS TU y RANEE ins cic cinco r a ws a a A E e EA A renee A ARS 150-216 MHz
Any 1 of 4 frequencies selectable by external switch. 0.005% crystal stability.
WET o a aD AAN TERA Frequency modulation, 12 kHz. Nominal 50 uS de-emphasis.
EE ETOC UONE ace ers KOEIE RD EAEEREN E EREA O ENERE EAS 10.7 MHz.
ER Sec Vit) serora r Ere E ANEN NENNEN 9-pole filter, 150 kHz wide, -6 dB/370 kHz wide, -60 dB.
aake rin WEE E r A r N E A A N 1.0 uV or less/0.5 aV typical for 12 db SINAD.
MMB ge REjSChOny anea oumas S Eo ENEN AANE ASEE ARESE ERENER IN IA AOT RON ENANS 90 dB.
Spur OuS KOJEC OE e E SETE AS ESETE A GREE RTSO E AERA EEEE EEE EEA 70 dB.
SiON SL to NOBe- RANO sones y oA NIEREN ASEE EATE EA ars, E lala aE EEEE ES (ultimate),
Commn a ndore ao Mey KE ATAA IE ETE EA ERNE EAE NE ar 104 dB.
Uncompandored: ceases an aH Ses OTS a GSO CUED BO AE TE 68 dB.
Seqwuelch Threshold ec ois ovine, snn nA NMA EONA RINE Nea aNS see eess Internal, set at 1.0 nV.
Suet ct tol oN 279 Uc] SE tT A Mee ep T PRR SE Sc Rh Ue cE eo era) els aed sa ce tt A Sa ee S 100 dB.
ERATE oA R A oT aes de edna S ip aes RMP: A EIN fbn cit EEO Rc] (ultimate) Ref: 12 kHz deviation, 104 dB.
PA ERR ET IPO UN pycee eg eaan oa Ges oe ae a ae Ref: 12 kHz deviation, 164 dB.
ARN OTO PPI SUOLTION crcrsyae garcia asus panniers OERA A OA 1% or Less. 0.5% typical at full output (1 kHz).

Audio Fregneney RESPONSO cris araea Ean EEA ane +1 dB, 100-15000Hz.
Headphone Onteat Jack Power 6 cscs cs caesie's nies ipese rosaman da EAEN E EE aea 1 kHz
350 mW (8 ohm load)
200 mW (16 ohm load)
100 mW (32 ohm load)
Line Eevee l OUE oicso:2.3eccainressssjarem sarna eies +14 dBm Maximum (12 kHz deviation).
Mic Level Quitas eso eeni EE EEE OE E e Ea aaa ee Adjustable,
-7 dB Maximum (200 ohms), (12 kHz deviation)
-21 dB Minimum (200 ohm), (12 kHz deviation)
Battery u ov csin's soss pa ose eete Four AA alkaline or nickel-cadmium required for interne! use.
WT-400 TECHNICAL INFORMATION
General Description: A belt worn battery Features: Small size, lightweight and is self-
powered VHF FM Transmitter ideally contained.
suited for any activity requiring a cordless
portable microphone.
Controls and Connections (Front Panel):
Power OFF/ON Switch .......... Low profile slide switch, allows access to power OFF/ON.
Microphone Gain Control ........s.ssess. Screwdriver adjust for microphone gain control.
Frequency SWE ason annaa Slide switch, choose either channel A or B Frequency.
Microphone Connect vs. iia eine nea eases eE EEEa mere 4-pin LEMO connector.
PGND iren 59:56 5 WERT ES ROCEPRNEB EES OERE Permanent, strain relief, flexible wire type.
Controls and Connections (Internal):
Compandor INJOUT Swieb ii <asxdnastsessniaevndemwgueay aaa ven Ea Slide switch.
AHEDBR os ie shin 9005 Wa sisia's Flexible wire type, permanently attached to the front panel (top)
Battery Compartment . ......<000cccseces For 9 volt alkaline, Mallory MN1606 or equivalent.
Average life is 6-8 hours minimum.
Battery Tests: sess sisi A red LED is mounted on the front panel. A fresh battery will cause
the LED to flash one time when the transmitter is turned on.
A week battery will illuminate the LED constantly. A dead or
unusable battery will show no indication.
WT-400 Specifications:
TIPE ies ho gS is ees ee TR Ea THAD ONES Es CEN E Direct FM, x 9 multiplication.
FROGUERCY RADE 6,000 0-0 rona aee 150-216 MHz (one of two frequencies selectable from
front panel switch, A or B) /0.005% crystal stability.
RE POMS RIOT ai gis a in Paine BA ESOC E eRe ee SS 50 mW maximum, 45 mW typical.
MOHOR cn. en ae sacked > EA are Maw AORERE. Frequency Modulated, 12 kHz deviation
Nominal 50 „S pre-emphasis.
Microphone Input ............. 100-10k ohm dynamic, or electret (+5 volts bias available).
Microphone Gain.......... Screw driver adjustable. 0.007 V RMS input required for 100%
modulation. 1.0 V RMS maximum acceptable input.
MOTtaan On LAO S ooa be es ATE ES eo Internal Compressor (Compandor System).
DRY oara EREE SEENA EAE Senses LNE aN EES E ES AEG 9.0 Volts nominal.
Current Grant aeo 56cm t's coends E ae Keach sence eraRuNomees cases 40 mA typical

ENG-4 CONTROLS AND CONNECTIONS
27049-A-003
ROTARY FUNCTION SWITCH/
METER DISPLAY-
RF ~
ARE
5 OFF 7
#28 VOC
FOR EXT OC — REMOVE BATT
1
|
XLR RECEPTICAL (Output to
Audio yata
i
l
EXTERNAL
|
LLEVEL
MONITOR
POWER
JACK
|
CONTROL
EARPHONE
JACE ames
BATTERY
PACK
Figure 2
` Front Panel — ENG-4
Antenna Jack: BNC type receptical, Refer to
Antenna Connection, Page 9 and Figure 9.
External Power Jack: For external power source,
9 VDC to 28 VDC/100 mA. Refer to Figure 7.
Rotary Function Switch/Meter Display:
ROTARY FUNCTION SWITCH - 4-position
switch:
= OFF Position - Non Functional - no current
drain.
AF Position - Indicates relative modulation of
the system (Audio Output).
RF Position - Indicates when the ENG-4 is
receiving a transmitter signal (Carrier
Indicator). Indication is relative only. Red bar
normally indicates weaker RF Signal, Green
bar normally indicates stronger RF Signal.
BATT Position - The meter indicates the
relative battery condition. Red bar indicates
weak or marginal batteries, Green bar indicates
good batteries.
5-
METER DISPLAY - A tri-color meter, relative
indication of Audio Output (AF), received signal
(RF), or battery condition. Selectable via the
Rotary Function Switch.
Earphone Jack: Connect to supplied earphone for
monitoring incoming audio from transmitter’s
microphone.
Level Monitor Control: Adjusts volume to
earphone output jack. DOES NOT AFFECT MIC OR
LINE LEVEL.
XLR Receptical: Output to audio sound system
(Amplifier/Mixer, Video-Cam, etc.). Output is adjust-
able for MIC Output by means of the MIC Level
Control. MIC/LINE Switch must be in the “MIC”
position to be adjustable. Refer to Receiver Output
Connection, pages 9 and 10.

MIC LEVEL CONTROL
|
E
|
|
|
| EEN
MIC fever
; Faa
@=.
. COMPANDOR
LINE [Ty ic IN I] Out
D
| |
LINE/MIC SWITCH |
|
|
COMPANDOR
IN/OUT SWITCH
CHANNEL SELECTOR
27049- A-004
L-4
L BATTERY RELEASE
BATTERY
HOLDER
“POPS UP”
Figure 3
Rear Panel — ENG-4
MIC Level Control: Rotary, screwdriver
adjustable control which controls MIC Level Output
to the front panel XLR receptical when selected by
LINE/MIC Switch. (200 ohm balanced MIC Level
Output).
LINE/MIC Switch: A slide switch that selects
LINE or MIC level output for front panel XLR
receptical. Use supplied plastic screwdriver to
operate slide switch to desired position.
Compandor IN/OUT Switch: A recessed slide
switch that controls compandor operation. Must be
set to match transmitter operation. Use supplied
plastic screwdriver to slide switch to desired position.
Channel Selector: Choice of 4 separate RF
channels (operating frequency). Must be set to match
transmitter channel or frequency. Screwdriver
adjustable.
Battery Release: Squeeze to release slide locks.
Internal battery holder pops up through top of case.

WT-400 CONTROLS AND CONNECTIONS
LOW BATTERY
ada
el
LED
TRAILING
WIRE
ANTENNA
|
MICROPHONE JACK--—. OFF/ON SWITCH
| N
| D
Telex WLM-200 or Equivalent
ADAPTOR CABLE - Connect to any
Impedance Microphone (100-10k ohm) |
{
(NOT SUPPLIED) MICROPHONE --+ &-CHANNEL SELECTOR
GAIN CONTROL (Frequency Switch)
Figure 4
Top Panel — WT-400
BATTERY COMPARTMENT
RELEASE
BATTERY
4 COMPANDOR
/
IN/OUT
SWITCH — ——\
"in"
&
w
"ouT"
Figure 5
Internal View — WT-400
Microphone Jack: The WT-400 was designed to Trailing Wire Antenna: A fully flexible 14-wave
easily interface with dynamic or electret antenna with a permanent strain relief.
microphones
in
the
100-10k
ohm
impedance
range.
A
‘
(10k ohm) resistor is permanently wired to the audio Microphone Gain Control: Screwdriver
circuit
to
provide
a
source
for
electret
microphones.
adjustable.
Adjusts
the
Audio
Gain
of
the
No XLR adaptor cable is provided with this system. microphone either up or down.
baea
hned
ie
galee
the
Pae
WOMI
Channel
Selector
(Frequency
Switch):
A
slide
switch which allows the user to select either Channel
OFF/ON Switch: A low profile slide switch is A or B frequency. Screwdriver adjustable.
ided to all OFF :
a
ACCHA
SOPOTE
AAN
Battery
Compartment
Release:
Depressing
the
Low
Battery
Indicator
LED:
Fart
of
the
battery
two
side
spring
latches
and
pulling
the
bottom
of
the
check
circuit.
When
the
power
switch
is
placed
in
the
case
downward
exposes
the
battery
compartment.
“ON”
position
the
LED
will
flash
one
time
if
the
r
:
battery
is
good.
A
poor
battery
will
cause
the
LED
to
Compandor
IN/OUT
Switch:
Internal
switch
be
illuminated
continuously
and
a
bad
or
unusable
allows
the
user
to
control
the
WT-400
compandor
battery
will
not
cause
any
illumination
at
all.
operation.
Must
be
set
to
match
receiver
operation.
oe

FOR
LINE
LEVEL
CONNECTION
(Less
Common):
This
connection
is
identical
to
MIC
LEVEL
connection
with
the
following
exceptions:
Place
the
output
level
switch
in
the
LINE
position.
A
2-conductor
phone
plug
will
be
needed
on
the
Mixer/Amplifier
end
of
the
audio
cable
to
connect
to
the
%
inch
line
input
jack.
See
Figure
11.
After
you
have
selected
either
MIC
or
LINE
operation,
turn
the
Monitor
Level
Control
down
(counterclockwise)
and
attach
a
monitor
earphone,
if
desired.
Adjust
listening
level
to
suit.
NOTE:
MIC
output
is
200
ohms,
adjustable
level
via
the
MIC
LEVEL
Control.
LINE
output
is
600
ohms,
fixed
level.
Set the Channel Selector Switch to match the
transmitter.
27049-A-013
TO AMPLIFIER
“Nxir
CONNECTOR
(CABLE NOT SUPPLIED)
STANDARD XLR TYPE CONNECTIONS
| = GROUND (COMMON)
2 = AUDIO [IN = PHASE}
3 — AUDIO (OUT-OF -PHASE )
Figure 11
“LINE LEVEL” Connection
TRANSMITTER SET-UP AND CONNECTIONS
Battery Installation: Insure that the power
switch is in the “OFF” position. Depress the two
spring latches (See Figure 12) on each side of the
case. Pull the front panel assembly forward
until the transmitter is removed from the case.
Insert the battery as shown in Figure 12,
making sure the proper polarity is observed.
27049-A-005
DEPRESS BOTH BATTERY
COMPARTMENT RELEASES
WHILE PULLING ON THE
BASE , TO REVEAL THE
BATTERY COMPARTMENT.
BATTERY
Figure 12
CompandorIN/OUT: Determine whether it
is desired to operate with the compandor IN or
OUT. Basically, this is a personal choice. Some
operators prefer to operate with the compandor
OUT, even at the expense of signal-to-noise
ratio and other advantages of compandor
operation. In any case place the internal
compandor switch (See Figure 5) to the “IN” or
“QUT” position, as desired.
NOTE:Double check to be sure that the receiver
compandor switch is in the same position as the
transmitter, either IN or OUT.
Microphone Connection: Reinsert the
transmitter into the case until the latches are
secure. Plug the microphone into the
transmitter. Refer to Figure 13. (If the
microphone brand that you are using is other
than Telex, request “Technical Bulletin No. PA-
84-1” for interface information.
Using the screwdriver provided, set the
Frequency Switch to A or B, to match the
receiver.

Battery Check: Set the power switch to the
“ON” position. Note that the battery LED
gh
i
ici
a
5
(labeled
LOW)
should
flash
one
time
on
a
good
1
=
SHIELD
27049-A-
010
battery.
A
poor
battery
will
cause
the
LED
to
be
1o
PEREIS
illuminated
continuously
and
a
bad
or
unusable
4-
NC.
a
er
eens
battery
will
not
cause
any
illumination
at
all.
Set the power Switch to the “OFF” position.
Refer to Figure 4.
Assuming that you have set-up the receiver
previously, proceed to the “Setting System Gain
Levels” section.
Figure 13
Microphone Connection
SETTING
SYSTEM
GAIN
LEVELS
Introduction:
If
you
have
followed
the
Transmitter
Gain
Setting:
instructions
up
to
this
point
you
should
now
be
STEP
1
ready
a
set
optimum
signal
gain
settings
on
Turn
the
ENG-4
receiver
Function
Switch
to
the
each
unit.
ryan
an
RF” position.
Set the WT-400 power switch to the “ON”
position. The ENG-4 meter should indicate in
the “GREEN” area. Turn the ENG-4 Function
Switch to the “AF” position. See Figure 14.
27049-A-009
pe - ENG-4 FUNCTION SWITCH TO "RF" POSITION
3-ENG-4 METER, NEEDLE IN
GREEN BAND
4 -FUNCTION SWITCH TO "AF"
POSITION
{URI
LPT
(CONTINUE TO NEXT STEP)
Figure 14
Checking Incoming RF Signal
Abts

STEP 2
The microphone “GAIN” Control on your WT-
400 has been.factory set for normal or average
audio levels.
High Level Setting: If your application is
in a high SPL (Sound Pressure Level) area
such as singing or instrumentation, the
factory gain setting is probably too high and
will result in overload or distortion. This will
be indicated on the ENG-4 receiver meter
between 0 to +3 (red).
Low Level Setting: If your application is
in alow SPL area, the factory gain setting is
probably to low. This will beindicated by low
meter indication on the ENG-4 meter, -20 or
below (white).
To correct either a too high or too low setting,
adjust the Microphone Gain Control (screw-
driver slot) on the front panel of the WT-400, so
that average audio causes the meter to indicate
between -20 to -5. An occasional overshoot into
the RED area is allowable. Refer to Figure 15.
27049-A-008
(METER — FRONT PANEL OF ENG-4)
TOO HIGH TOO LOW
CCW — TURNS CW — TURNS
AUDIO GAIN AUDIO GAIN
DOWN UP
Figure 15
High Level and Low Level
Gain Adjustment
-12-
Receiver Gain Setting: After the trans
mitter gain has been properly set, you are nov
ready to set receiver gain.
NOTE: Insure that the Compandor IN/OU™
switch on the receiver agrees with the trans
mitter Compandor IN/OUT Switch.
Set the LINE/MIC Switch as required. In th.
LINE position, thereis no adjustment. The Lin:
output level is fixed. In the MIC position, th:
output level is adjustable via the MIC Leve
Control (screwdriver slot). Refer to Figure 3.
Adjust the level to accomodate the mixer o:
other audio system.
NOTE: This control does not affect the ENG
4 meter indication.
If monitoring is required, plug the earphone
(supplied) into the Monitor Jack on the front o:
the ENG-4 receiver and adjust the Monito:
Level Control for comfortable listening
Adjusting the Monitor Level DOES NOT affec
the MIC LEVEL. They are independent
functions. Refer to Figure 2.

SYSTEM WALK-THRU
General: Now that you have successfully
“set up” your Telex Wireless System and turned
on your sound equipment (amplifier/mixer,
video cam etc.), you are ready to test the overall
performance by “Walking” the Telex
transmitter through the areas in which you will
be using it. .
The “system walk-thru” can detect the
following RF problems:
Weak signal strength caused by:
1. Poor antenna location
2. RF “Trouble Spots”
3. Operating distance beyond
System capability
4, Malfunctioning system
Carrier Indication: Under normal condi-
tions with the Rotary Function Switch in the
“RF” position the carrier indication on the
meter should always be center scale or higher
(green area) with the transmitter “ON”. See
Figure 14.
“Weak Signal” conditions will result in low
meter indication with the potential of actually
“hearing” this in the sound system.
Audio Feedback: The system walk-thru can
also uncover locations in the performing area
which are prone to audio feedback (usually
sounds like a “squeal” or a “howl”). Feedback
can be a problem for any microphone —
whether wired or wireless. To eliminate
feedback observe placement of the microphone
and any nearby loudspeakers. i
In 99% of allinstances you will set up your Telex
Wireless System, walk it through and achieve
` error-free performance. If in the rare instances
your Telex System does not “pass” during your
walk-thru evaluation, refer to the last two
sections of this manual which deal with
Antenna Information and System Trouble-
shooting.
TROUBLESHOOTING
Reread the sections of this manual to make sure
you have completed system set-up properly.
PROBLEM SOLUTION
DISTORTION — System’s audio quality
seems distorted at medium to high input
levels.
HISS — System seems to produce a “hiss”
which is undesirable.
LOW OUTPUT — System produces a lower
output level than wired microphone in sound
system.
Reduce audio gain on the transmitter by ad-
justing gain control as suggested on Pages 11
and 12.
Check the gain settings on both the transmit-
ter and receiver as indicated on Pages 11 and
12, they may be too low. Check Compandor
IN/OUT Switch.
Check the gain settings on both the transmit-
ter and receiver as indicated on Pages 11 and
12, they may be too low.

TROUBLESHOOTING CONT.
PROBLEM SOLUTION
FEEDBACK — Moving around performing
area produces “squeal” or “howl” in various
locations.
DROPOUTS — When moving around per-
forming area there seem to be locations
where the signal ‘“‘swooshes” or completely
disappears.
INTERFERENCE — System picks up
signals other than wireless transmitter.
REDUCED DISTANCE — System doesn’t
operate as far as it once did. System doesn’t
operate as well as you think it should.
BATTERIES DON’T LAST
(TRANSMITTER)
BATTERIES DON’T LAST
(RECEIVER)
If you are unable to solve the problem contact
the dealer from whom you purchased the
system for assistance.
Reduce gain settings on wireléss system
and sound system. Readjust nearby loud-
speakers.
Make sure the antenna is connected and fol-
low the location suggestions on Pages 16 and
17. Change the location of the receiver/
antenna or avoid the bad area with the
transmitter.
Make sure Telex transmitter is turned on — this
will usually eliminate the interfering signal.
If problems persist with Telex transmitter on,
you will probably need to have your system’s
frequency changed to another channel.
Transmitter battery is possibly in need of
replacement. Receiver antenna possibly
located incorrectly. See Pages 16 and 17 for
proper placement.
If using “throw away” batteries, make sure
they are alkaline (Mallory MN1604 or
equivalent). If using nickel-cadmium, make
sure it is an 8.4 volt, 7.2 volt batteries won't
work. Refer to Page 15.
If using “throw away” batteries, make sure
they are AA alkaline (Mallory MN1500) or
equivalent.
1 4-

BATTERY INFORMATION
-
General: Improper battery selection, use, in-
stallation and care are the cause of numerous
wireless system failures.
Alkaline Batteries: Alkaline batteries such
as Mallory’ss DURACELL® or Eveready’s
ENERGIZER® provide the most reliable
operation in wireless transmitters. The use of
low cost carbon-zinc batteries is NOT
recommended.
Nickel-Cadmium Batteries: These
batteries can save you money in the long run, as
they can be recharged, but they can also cause
disappointing wireless performance. If you
want to use rechargeable nickel-cadmium
batteries you must select a heavy duty nickel-
cadmium. Conventional 9 volt sizesuch as GH®
or Radio Shack® are only capable of providing
7.2 volts, which is not sufficient to power the
Telex WT-400 transmitter.
Nickel-Cadmium Memory Effect: For
maximum performance and longer life from
nickel-cadmium batteries you should
completely discharge them whenever possible.
This can be done by simply leaving the Telex
transmitter turned on overnight. If nickel-
cadmiums are not discharged on aregular basis
they will remember how long you use them for
each performance and will not have the ability
to retain their original performance.
ENERGIZER® is a registered trademark of Union Carbide
Corporation.
DURACELL® is a registered trademark of Duracell Inc.
-15-
Tapoca Tie
Conventional “RAY-O-VAC” Not
Carbon Zinc Recommended
Does Not Work
1% to 2 Hours
per charge
Alkaline “MALLORY”
MN1604 or Equivalent
GE or Radio Shack Nickel-
Cadmium Rechargeable
Varta or Gould “Again and
Again” Nickel-Cadmium
Rechargeable
Table 1
Battery Information for WT-400
Oe RE
6-8 Hours
Alkaline “EVEREADY” #E91
or Equivalent.
EVEREADY Nickel-Cadmium
#CH15 or Equivalent
45 Hours
Table 2
Battery Information for ENG-4
GE® is a registered trademark of General Electric Company
Radio Shack® is a registered trademark of the Tandy Corp.
SROH HHIHHIHHII

——— RES
nr ES SPREE PD SE tS
ANTENNA INFORMATION
Antenna Alignment: To align the antenna
properly refer to Figure 16.
27049-8- O16
Figure 16
Antenna Alignment
Do and Don’t
Antenna Polarization: The Telex Wireless
System is “Vertically Polarized”. This means
both the transmitting and receiving antennas
should operate in the vertical position.
27049-A-O17
RECEIVER
ANTENNA
TRANSMITTER me
Figure 17
Vertically Polarized Antenna
Antenna Placement: Keep the distance
between the transmitter and the receiver's
antenna as short as possible. The greater the
distance, the weaker the signal.
27049 -B-024
/
/
/
/
Figure 18
Distance Between Transmitter
and Receiver
Make sure the “signal path” between the
transmitter and receiver’s antenna is
unobstructed. You should always be able to
visibly locate the antenna at all times.
2704 -4-0r8
Figure 19
Keeping Site Clear to Antenna

|?
à)
$?
E:
Attempting to operate the wireless system
27049-8-021
through or around walls, ceilings, metal objects,
etc., will reduce system range and performance.
27049-B-020
WALLS, CEILING, METALLIC OBJECTS, ETC. CAN
SIGNAL REFLECTION OFF A METAL OBSTRUCTION De r PRA >
CAUSES REDUCED SIGNAL AND “MULTIPATH” ene a
Figure 20 Fi
s gure 21
Operating Through Obstructions Multipath Reception
Dropouts/ Picket Fencing: A “signal
dropout” can occur at any operating distance
and is caused by the direct signal from the
transmitter and reflected signals from the
transmitter (called multipath) arriving at the
receiving antenna out-of-phase.

FCC REGULATION
The Telex. Model WT-400 Transmitter is Type Accepted under United States Federal Com-
munications Commission Parts 90 and 74. The receiver ENG-4 is Type Accepted under Part
15 of the Federal Communications Commission. Licensing of Telex equipment is the user’s
responsibility and licensability depends upon the user’s classification, user’s application, and
frequency selected. Telex strongly urges the user to contact the appropriate telecommunica-
tions authority for any desired clarification.
CAUTION: Changes or modifications made by the user could void the user’s authority to
operate the equipment.
eral ee aces lt bi

ACCESSORIES
Lapel
Microphone
-
Electret
type
comes
with
Nickel-Cadmium
Battery
-
For
WT-400
tie
clip
and
lapel
clip
holder.
Transmitter
8.4
Volts
WLM-100/Order
No.
63852-000
Order
No.
63912-000
WLM-200/Order No. 63852-001
PH-22 Headworn Microphone - Close talk-
ing, noise cancelling electret.
Order
No.
64327-002
Carrying
Case
-
For
the
WT-400
Trans-
mitter
Order No. 59756-000
Adaptor Cable - SLR to LEMO adaptor
cable for WT-400
Order No. 63841-000
Carrying Case - For the ENG-4 Receiver
Order No. 70372-000
27049-A-936
(ee = ry ts
BC-2 Battery Charger - For charging nickel-
cadmium battery used in WT-400.
Order No. 64267-000
aroas aore

REPLACEMENT PARTS
Battery Sled Assembly - For ENG-4 Antenna Replacements - For ENG-4 anc
Receiver. Replacement or for extra battery WT-400. When ordering antenna order b:
holder. the frequency of the receiver.
Order No. 64480-000
ENG-4 Replacements
Earphone Assembly - For ENG-4 for 150-158 MHz/Order No. 57032-005
monitoring incoming audio from 158-165 MHz/Order No. 57032-006
transmitter’s microphone. Four separate 165-175 MHz/Order No. 57032-000
parts. 175-185 MHz/Order No. 57032-001
Cord, CMT-98 185-195 MHz/Order No. 57032-002
Order No. 60013-015 195-205 MHz/Order No. 57032-003
B Eartip, ET-1 205-216 MHz/Order No. 57032-004
Order No. 35608-000
C Earloop, AEF-2 WT-400 Replacement
Order No. 09252-000 150-216 MHz/Order No. 70277-000
D Earphone, RTW-04
Order No. 60012-005
\ p
CF
For the ENG-4
-20-