Telex RadioCom TR-300 User manual

Telex
Operating Instructions
PROFESSIONAL
WIRELESS
INTERCOM SYSTEM
TR-300, BTR-300
R
Ext Intercom Aux Audio 1
3
4
2
Portable Station Connect
BTR-300
Talk
Headset Controls
Volume
Power
Headset
Portable Transmit On
Gain O/M
Push Twice to Latch
RadioComä
RadioComä
TR-300

TABLE OF CONTENTS
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
BTR-300 BASE STATION TRANSCEIVER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
CONTROLS AND CONNECTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
TR-300 BELT-PACK TRANSCEIVER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
CONTROLS AND CONNECTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
EQUIPMENT SET-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
BTR-300 SET-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
ANTENNA INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
TR-300 SET-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
PRE-WALK-THRU CHECKLIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
SYSTEM OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
BTR-300 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
TR-300 OPERATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
ENABLING AUDIO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
SETTING SYSTEM GAIN LEVELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
SYSTEM WALK-THRU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
BATTERY INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
ACCESSORIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
CUSTOMER SERVICE INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
FCC INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
-i-

INTRODUCTION
GENERAL DESCRIPTION
This manual covers the BTR-300 Base Station
and the TR-300 Portable Transceiver.
The RadioCom Models BTR-300 and TR-300
were specifically designed to provide the user
with a highly flexible wireless two-way com-
munication system with the capability to inter-
face with a wired intercom system and other
auxiliary audio.
At the BTR-300 operator’s command, the
remotes may communicate with each other,
with a wired intercom system or with an auxil-
iary system. The BTR-300 Base Station with
its one transmit and four receive channels is
designed to operate in full duplex (simulta-
neous two-way communications) with up to
four TR-300 Belt Pack transceivers. See block
diagram in Figure 1.
Figure 1
Block Diagram of System
-1-
WIRED
INTERCOM
FM
RECEIVER
REC
1
REC
2
REC
3
REC
4
TRANSMITTER
EARPHONE
MICROPHONE
HEADSET
AUXILIARY
OUTPUT
AUXILIARY
INPUT
MICROPHONE
EARPHONE
HEADSET
RECEIVER
TRANSMITTER
TR-300
ANT
ANT
ANT
ANT
RF CARRIER
SIGNAL
F
SIGNAL
ANT
ANT
RF CARRIER
SIGNAL
F
SIGNAL
R CARRIER
F
SIGNAL
BTR- 300

The system operates on selected frequencies
within the 150-216 MHz band.
The BTR-300 system is fully compatible with
a number of other wired intercom manufactur-
ers units. See the BTR-300 Setup Section for
additional information.
The TR-300 Transceiver operates in the con-
tinuous transmit mode with the audio acti-
vated by a switch. As many as four TR-300
belt-pack transceivers can operate in a fully
duplex network with one RadioCom Model
BTR-300 Base Station.
-2-

BTR-300 BASE STATION TRANSCEIVER
TECHNICAL INFORMATION
-3-
SPECIFICATIONS BTR-300
Input Power (minimum) ....................................................................................12V AC/DC at 360 mA
Intercom Output ........330 mV (Low) or 1 V (Hi) RMS into 300 ohm load typical (at rated deviation)
Intercom Input (Gain Minimum) .........................................300 mV RMS typical (for rated deviation)
Auxiliary Output.............................................2 V RMS into 600 ohm load typical (at rated deviation)
Auxiliary Input (Gain Maximum) .........................................60 mV RMS typical (for rated deviation)
Local Headset Input.......................................................................................2 mV RMS input nominal
1.5 mV RMS input at compression (Dynamic)
Local Headset Output .............................................................32 mV maximum output into 600 ohmst
Speaker/Local Monitor Output (into 8 Ohms) ............................................2 Watts (at rated deviation)
Temperature Range ................................................................................-4°F to 130°F (-20°C to 55°C)
Dimensions.............................................................................................15.75” W x 1.75” H x 10.5” D
(40 cm x 4.5 cm x 26 cm)
Weight................................................................................................................................4.5 lbs (2 kg)
Transmit
RF Frequency Range ........................................................................................................150-216 MHz
RF Frequency Stability................................................................................Crystal Controlled, 0.005%
RF Power Output............................................................................................................50 mW Typical
Modulation...........................................................................................................FM, 3 KHz deviation.
115 micro-seconds Pre-emphasis
Transmit Antenna....................................................................................................5/8-wave (supplied)
SO239 connector on chassis
Modulation Limiter ................................................................................................Internal Compressor
Modulation Frequency Range ............................................................................300 to 5000 Hz ±2 dB
Radiated Harmonics and Spurious Emissions ..........................................................................-45 dBC,
Exceeds FCC Specifications
FCC ............................................................................................Type Accepted Under Parts 90 and 74

FEATURES
The RadioCom Model BTR-300 is a Base
Station with one transmitter and four re-
ceivers. It is designed for portable two way
communication with the capability for inter-
face to other audio systems. Features include:
·An extremely flexible unit that has the capa-
bility to communicate at one time with up to
four portable stations and wired stations (in-
tercom and/or other audio source).
·Powered by an external AC supply via the
power jack on the rear of the unit. It can
also be powered by any 12V AC/DC 700
mA source.
·Intercom connections with the ability to in-
terface with most wired intercom systems.
·RF light indicator for each portable station.
·All metal case for superior shielding.
·Table or rack mountable.
-4-
SPECIFICATIONS BTR-300 (Cont.)
Receive
RF Frequency Range .......................................................................................................150-216 MHz
RF Frequency Stability................................................................................Crystal Controlled, 0.005%
Type ...........................................................................................Dual conversion superheterodyne, FM
RF Sensitivity ................................................................................Less than 0.6 µV for 12 dB SINAD
IF Selectivity ........................................................................3 dB at 30 kHz (4 pole Monolythic Filter)
Image Rejection ..............................................................................................................65 dB or better
Squelch Quieting ...........................................................................................................................90 dB
Squelch Threshold........................................................................................................1.0 µV (Internal)
Signal-to-Noise Ratio ....................................................................................................................90 dB
Receive Antenna .....................................................................................................5/8-wave (supplied)
SO239 connector on chassis
Distortion.................................................................................................Less than 1% at Rated Output

CONTROLS and CONNECTIONS
FRONT PANEL (Refer to Figure 3)
Power ON/OFF Switch: Push this switch
once to turn power ON; push it again to turn
the power OFF.
Power ON Indicator: The Power ON light is
illuminated when the Power ON/OFF Switch
is pushed in the ON Position.
Local Headset Connector: Four pin XLR
Connector for Input/Output (plug for Telex
units and jack for RTS units). The headset
jack will accept many Telex model headsets.
Compatible with other intercom headsets with
four pin XLR connectors that are wired as
shown in Figure 2.
Figure 2
Headset XLR Connector Wiring
Local Headset Volume: Adjusts volume to
Local Headset. DOES NOT AFFECT MI-
CROPHONE GAIN.
Mic On-Push-to-Talk/Lock-to-Talk Switch:
Enables the local headset microphone audio
function.
NOTE: DOES NOT control base station RF
transmit.
Local Push-to-Talk Indicator: Will be illu-
minated whenever the talk function is on.
Local Microphone Gain Control and
Overmodulation Indicator: A screwdriver
adjustable control is provided to control the
input level of the local headset mic. This input
is protected from overloads by means of a
gain compressor whose operation is signaled
by the gain light indicator.
Portable Enable Switches and Indicators:
When in the “IN” position, the Enable
switches allow the user of the corresponding
portable unit to be heard by others connected
to the system. When in the “OUT” position,
the respective portable will be muted, but this
portable will still be able to hear all other se-
lected remotes and interfaces. The indicators
(Portable Transmit On) normally show the
presence of a portable transceiver in use on
the channel corresponding to that indicator.
-5-
BALANCED
AUDIO OUT
(3 AND 4)
MICROPHONE
GROUND (1)
MICROPHONE
AUDIO (2)
1
23
4
BALANCED
A
UDIO OUT
(3 AND 4)
MICROPHONE
GROUND (1)
MICROPHON
E
AUDIO (2)
4
32
1
Plug for Telex Unit
Jack for RTS Unit

External Intercom Switch, Level Control,
and indicator: This switch enables the wired
intercom interface when “IN”, and disables it
when “OUT”. For RTS intercoms, the “IN”
position is channel 1 and the “OUT” position
is channel 2. A screwdriver adjustable control
is provided to control the input level of the
wired intercom.
Auxiliary Audio Enable Switch, Level Con-
trol, and Indicator: The switch enables and
disables the Auxiliary interface when “IN”
and “OUT”, respectively. The function of the
level control here is the same as that described
for the intercom.
REAR PANEL (Refer to Figure 4)
Transmit and Receive Antenna Connec-
tors:
Attach 5/8-wave antennas (supplied) to these
connectors; Antenna color should match the
“color dot.”
Transmit Switch: Slide switch that allows the
operator to select one of three transmit modes.
In the “OFF” position, the transmitter is al-
ways off. This mode may be used if the base is
functioning solely as a monitor. In the
“CONT” position, the transmitter is always
on. This continuous mode is recommended
over the “REMOTE” mode. In the “RE-
MOTE” position, the transmitter is enabled
only when one or more portables are active.
Headset Microphone Select Switch: This
switch allows the user to select either an
Electret or Dynamic microphone.
Intercom Connectors: Connections to inter-
face the BTR-300 with a wired intercom sys-
tem.
Auxiliary Output/Input Connectors: Can be
used for 2-way (four wire) input and output to
the BTR-300 or as a simplex input or output.
Typical uses are 4 wire intercom’s, tape re-
corders, public address inputs or outputs.
Power Jack: For external AC supply adaptor
(supplied).
Speaker Jack: Allows the use of an external
monitor if desired. An 8 ohm speaker is rec-
ommended.
Speaker Volume Control: Screwdriver ad-
justable. Adjust clockwise to increase speaker
volume or counterclockwise to decrease
speaker volume.
NOTE: Leave setting counterclockwise if no
speaker is attached.
-6-

-7-
Ext Intercom Aux Audio 1
3
4
2
Portable Station Connect
BTR-300
Talk
Headset Controls
Volume
Power
Headset
Portable Transmit On
Gain O/M
Push Twice to Latch
RadioCom
ä
POWER ON
INDICATOR
POWER ON-OFF SWITCH
LOCAL HEADSET CONNECTOR
LOCAL HEADSET VOLUME
MIC ON PUSH-TO-TALK/
LOCK-TO-TALK SWITCH
LOCAL PUSH-TO-TALK INDICATOR
LOCAL MIC GAIN CONTROL
LOCAL MIC
OVERMODULATION
INDICATOR
EXTERNAL
INTERCOM
AUXILIARY
AUDIO
PORTABLE ENABLE
SWITCHES AND INDICATORS
Figure 3
Front Panel BTR-300

-8-
PUSH PUSH
Transmit
Antenna
Auxiliary
Audio Output
Auxiliary
Audio Input
Headset Mic
Dyn Elt Off
Remote
Cont
Loop Thru
Intercom Intercom
Loop-Thru
Speaker
Power
AC/DC 12V
700 mA
Transmit
AUXILIARY OUTPUT CONNECTOR
AUXILIARY INPUT CONNECTOR
INTERCOM CONNECTORS
Receive
Antenna
Intercom
Loop-Thru
RECEIVE
ANTENNA CONNECTOR
POWER JACK
SPEAKER VOLUME CONTROL
SPEAKER / LOCAL MONITOR ( 8 MIN.)
TRANSMITTER SWITCH
HEADSET MIC SELECT SWITCH
TRANSMIT ANTENNA
CONNECTOR
ANTENNA
COLOR DOT
ANTENNA
COLOR DOT
Telex Communications Inc.
BTR-300
MADE IN U.S.A.
Volume
8
Figure 4
Rear Panel BTR-300

TR-300 BELT-PACK TRANSCEIVER
TECHNICAL INFORMATION
-9-
SPECIFICATIONS TR-300
Overall
Power Requirements ..............................................................6 AA cells (Alkaline, NEDA, MN 1500)
Nickel-metal hydride optional
Current Drain....................................................................................................................typical 82 mA
Temperature Range ................................................................................-4°F to 130°F (-20°C to 55°C)
Dimensions...............................................................................................4.25” W x 4.125” H x 2.0” D
(108mm x 105mm x 51 mm)
Weight ..........................................................................................................13 oz (369g) with batteries
Transmit Antenna............................................................................................1/4-wave wire (attached)
Receive Antenna .............................................................................................1/4-wave wire (attached)
Transmit
RF Frequency Range ........................................................................................................150-216 MHz
RF Frequency Stability................................................................................Crystal Controlled, 0.005%
RF Power Output............................................................................................................50 mW Typical
Modulation........................................................................................................FM, 3000 Hz deviation,
115 micro-seconds Pre-emphasis
Modulation Limiter ................................................................................................Internal Compressor
Modulation Frequency Range .........................................................................300 to 5000 Hz +/_2 dB
Microphone Audio Input ..............................................................................................30 to 3500 ohms
Microphone Input Sensitivity.................................................................2 mV Dynamic, 4 mV Electret
Radiated Harmonics and Spurious Emissions ..........................................................................-45 dBC,
Exceeds FCC Specifications
FCC ............................................................................................Type Accepted Under Parts 90 and 74
Receive
RF Frequency Range ........................................................................................................150-216 MHz
RF Frequency Stability ......................................................................Crystal Controlled, 0.005% Type
Dual Conversion Superheterodyne, FM
RF Sensitivity .................................................................................Less than 0.5 µV for 12 dB SINAD
IF Selectivity ........................................................................................3 dB at 30 kHz (Ceramic Filter)
Image Rejection ..............................................................................................................70 dB or better
Squelch Quieting ...........................................................................................................................90 dB
Squelch Threshold........................................................................................................3.0 µV (Internal)
Signal-to-Noise Ratio ....................................................................................................................90 dB
Audio Output ......................................................................................32 mW into 600 ohms (Headset)
Distortion.................................................................................................Less than 1% at Rated Output

FEATURES
·Lightweight, small size and is
self-contained.
·2 separate antennas, one for transmit, the
other for receive.
·Push-to-Talk with Lock-to-Talk feature
switch for the TR-300 and Push-to-Transmit
with Lock-to-Transmit feature for the
TR-300P.
CONTROLS AND CONNECTIONS
EXTERNAL CONTROLS (Refer to Figure 6)
Volume OFF/ON Control: This thumbwheel
control serves as both an off/on switch and as
a volume control.
Low Battery and Overmodulation
Indicator Light:
Low Battery Indicator: Part of the battery
check circuit. When the power switch is
placed in the “ON” position the light will
flash one or more times if the battery is
good. A poor battery will cause the light to
illuminate continuously and a bad or unus-
able battery will not cause any illumination
at all.
Overmodulation Indicator: Uses the same
light as the low battery indicator. During
the talk mode, if the microphone gain is too
high, the light will illuminate when talking.
Push-To-Talk, Lock-To-Talk Switch:
This switch enables the talk function.
Talk Indicator Light: (Labeled “talk”) will
be illuminated whenever the talk function on
the TR-300 is enabled.
Headset Connector: A four pin XLR connec-
tor for Input/Output. (Plug for Telex, Jack for
RTS units). The headset jack will accept many
different Telex model headsets. Compatible
with other intercom headsets with four pin
XLR connectors that are wired as shown in
Figure 5.
Plug for Telex Units
Jack for RTS Units
Figure 5
Headset XLR Connector Wiring
Charge Jack: Allows nickel-metal hydride
batteries to be charged without removing them
from the unit.
-10-
BALANCED
AUDIO OUT
(3 and 4)
MICROPHONE
GROUND (1)
MICROPHONE
AUDIO (2)
MICROPHONE
GROUND (1)
MICROPHONE
AUDIO (2)
BALANCED
AUDIO
OUTPUT
(3 and 4)

Figure 6
External Controls, TR-300
-11-
Bat/
ovmod talk talk
BELT CLIP
LOW BATTERY / OVERMODULATION
INDICATOR LIGHT
TALK INDICATOR LIGHT
PUSH-TO-TALK/
LOCK-TO-TALK SWITCH
VOLUME OFF/ON CONTROL
HEADSET
CONNECTOR
TRANSMIT ANTENNA
RECEIVE ANTENNA
BATTERY
CHARGE
JACK

Figure 7
Internal controls, TR-300
INTERNAL CONTROLS (Refer to Figure 7)
Microphone Gain Control: Screwdriver ad-
justable by removing belt clip and prying out
the small rubber plug to the right of the screw
boss.
Dynamic/Electret Switch: This switch allows
selection of “D” when using a Dynamic Mi-
crophone or “E” when using and Electret Mi-
crophone.
Battery Compartment: Holds 6 AA batteries
in a removable battery holder (supplied).
-12-
FCC ID: B5DMXXX
S/N:
MIC
ED
BATTERY COMPARTMENT
DYNAMIC / ELECTRET
SWITCH
ACCESS TO MICROPHONE
GAIN CONTROL
CANADA IIIIIIIIIII

EQUIPMENT SET-UP
BTR-300 SET-UP
UNPACKING
Unpack your BTR-300 and TR-300 System. If
there are any damages or shortages, refer to
the “Warranty Service Information” section in
this manual.
INTERNAL INTERCOM SWITCHES
The BTR-300 has internal switches that allow
it to accommodate intercom systems other
than what it was set to interface with when
manufactured. Product No. 71276XXXX is set
for Telex Audio Com and similar systems.
Product No. 71280XXXX is set for RTS 2
wire and similar systems. Units originally set
for Telex may be set to RTS and vice versa.
Both models may be set to interface with
Clearcom, and 4 wire RTS/McCurdy matrix
type systems. The following paragraphs ex-
plain how to change the switches if necessary.
Remove Cover: Remove the cover screws
(13) and lift off the cover.
DIP Switch: See Figure 8 and Table 1. Set the
DIP switch as shown in the table.
High/Low Switch: See Figure 8 and Table 2.
Set the high/low switch as shown in the table.
Intercom Switch: See Figure 8 and Table 2. Set
the switch to 2 wire for all 2 wire systems. Set
the switch to 4 wire if the BTR is to be con-
nected to a balanced 4 wire intercom system
through the Auxiliary input and output jacks.
Note: Do not connect both 4 wire and 2 wire sys-
tems at the same time. Loud feedback may result.
Replace Cover: Carefully align the cover and
replace the screws.
INTERCOM JACK WIRING
CONFIGURATIONS
See Table 3 for the wiring of the intercom and
auxiliary jacks.
Table 1
Table 2
-13-
DIP SWITCH POSITION
123456789
Telex Audiocom ON ON OFF ON OFF ON OFF OFF ON
RTS 2 wire OFF OFF ON OFF ON OFF ON ON OFF
Clearcom ON OFF ON ON OFF OFF OFF ON ON
4 Wire N/A N/A N/A N/A N/A N/A N/A N/A N/A
INTERCOM LOW/HIGH INTERCOM
TYPE SWITCH SWITCH
Telex
Audio Com Low 2 wire
RTS High 2 wire
Clearcom Low 2 wire
4 wire N/A 4 wire

Table 3
Pin Wiring for Rear Panel Jacks
Figure 8
Internal Intercom Switches
-14-
Internal Auxiliary Audio Out Auxiliary Audio Input Intercom Loop Thru
Switch (both jacks)
Settings Pin 1 Pin 2 Pin 3 Pin1 Pin 2 Pin 3 Pin 1 Pin 2 Pin 3
Telex Audio
Com Ground 600 ohm 600 ohm Ground 2.2K ohm 2.2K ohm Ground Balanced Balanced
Balanced Balanced Balanced Balanced
RTS 2 wire Ground 600 ohm 600 ohm Ground 2.2K ohm 2.2K ohm Ground Channel Channel
Balanced Balanced Balanced Balanced 1 2
Clearcom Ground 600 ohm 600 ohm Ground 2.2K ohm 2.2K ohm Ground Power Audio
Balanced Balanced Balanced Balanced
4 wire Ground Balanced Balanced Ground Balanced Balanced Do Not Do Not Do Not
Intercom Intercom Intercom Intercom Use Use Use
Out Out In In
FRONT
DIP SWITCH
ON
123456789
INTERCOM
4
W
I
R
E
2
W
I
R
E
CA101
LOW
HIGH

RACK MOUNTING
To rack mount the BTR-300 base transceiver
do the following:
Remove the front two #6-32 x 3/8” screws
on each side of the transceiver as shown in
Figure 9.
Place the rack mount brackets (supplied) on
either side of the unit and insert three #6-32 x
3/8” screws for each bracket. Tighten the
screws securely.
Insert the BTR-300 into your 19” rack enclo-
sure and insert four (4) #10-32 x 3/8” Phillips
pan head screws (supplied) in each corner of
the rack mount brackets and secure to your en-
closure.
Figure 9
Attaching Brackets for Rack Mounting
-15-
REMOVE SCREWS
(TYPICAL BOTH SIDES)
BTR-300

ANTENNA INFORMATION
ANTENNA CONNECTIONS
The BTR-300 is supplied with two (2) anten-
nas. One 5/8-wave antenna for Transmit and
one 5/8-wave antenna for Transmit and one
5/8-wave for Receive.
Assemble the 5/8-wave antenna by screwing
the two sections together as shown in Figure
10. Both sections of the BTR-300 5/8-wave an-
tennas must be used. Leaving off the top sec-
tion will result in reduced range.
Figure 10
5/8-wave Antenna Assembly
To insure that the frequency of the antennas
match the receiver and transmitter of the
BTR-300, match the color dot on the antenna
with the color dot on the BTR-300
Attach the antennas to the antenna input re-
ceptacles unless the BTR is rack mounted.
Tighten the connector securely.
Figure 11
Attaching 5/8-wave Antenna
-16-
DO DON’T
COLOR DOTS

Remoting Antennas: It will be necessary to
remote both the transmit and receive antennas
on the BTR-300 when it is rack mounted.
Connect the coax cable assembly (not sup-
plied), to the receive antenna receptacle and
mount the 5/8-wave antenna. The antenna can
be attached to either a wall mount bracket or a
microphone stand bracket (not supplied). See
“Accessory” section for order information.
You will also need to remote the transmit an-
tenna in the same manner. Connect a coax ca-
ble assembly to the transmit antenna
receptacle. Mount the 5/8-wave antenna by at-
taching it to a bracket (not supplied).
Figure 12
Remoting Antennas when Rack Mounted
-17-
ExtIntercom Aux Audio 1
3
4
2
Portable Station Connect
BTR-300
Talk
Headset Controls
Volume
Power
Headset
Portable Transmit On
Gain O/M
Push Twiceto Latch
RadioComä
6 FT (2m)
or more
is best
2 FT (60cm)
minimum
distance

ANTENNA POLARIZATION
The Telex Wireless Intercom System is “Ver-
tically Polarized”. This means both the trans-
mitting and receiving antennas should operate
in the vertical position.
Figure 13
Vertically Polarized Antennas
ANTENNA PLACEMENT
Proper antenna placement probably has the
most effect on you TELEX Wireless intercom
System’s overall performance. The following
suggestions will result in optimum perfor-
mance.
Proper placement of the TR-300 can be criti-
cal. The trailing antennas should “dangle”
freely. “Wadding” the antennas up and placing
them in a pocket, etc., will reduce system
range.
It is suggested that the unit be worn on the belt
or pocket with both antenna’s hung vertically
for best operating range and performance.
Figure 14
Proper Dressing of the Antennas
Keep the distance between the base
(BTR-300) and the belt pack (TR-300) anten-
nas as short as possible. The greater the dis-
tance, the weaker the signal. However, the
portables should be a minimum distance of 10
feet from the base station and each other for
best performance.
Make sure the “signal paths” between the
BTR-300 and remotes are unobstructed. You
should always be able to visibly locate the an-
tennas for best performance.
Figure 15
Keeping Site Clear to Antenna
-18-
Headset
RadioComä
TR-300
ExtIntercom Aux Audio 1
3
4
2
Portable Station Connect
BTR-300
Talk
HeadsetControls
Volume
Power
Headset
Portable TransmitOn
Gain O/M
Push Twiceto Latch
RadioComä
RadioComä
TR-300
SIGNAL REACHES
ANTENNA AT FULL
STRENGTH WITH NO
OBSTRUCTIONS
Headset
ExtIntercom Aux Audio 1
3
4
2
PortableStation Connect
BTR-300
Talk
HeadsetControls
Volume
Power
PortableTransmit On
Gain O/M
PushTwice to Latch
RadioComä
RadioComä
TR-300
RadioComä
TR-300