Telex RADIOCOM BTR-300B User manual

Telex
Operating Instructions
PROFESSIONAL
WIRELESS
INTERCOM SYSTEM
TR-300, TR-300P,
BTR-300, BTR-300B

TABLEOF CONTENTS
INTRODUCTION ..............................................................................................................................1
GENERAL DESCRIPTION............................................................................................................1
BTR-300 BASE STATION TRANSCEIVER..................................................................................3
TECHNICAL INFORMATION......................................................................................................3
SPECIFICATIONS..................................................................................................................3
FEATURES..............................................................................................................................4
CONTROLS AND CONNECTIONS..............................................................................................5
FRONT PANEL................................................................................................... ....................5
REAR PANEL................................................................................................... ......................6
TR-300 BELT-PACK TRANSCEIVER...........................................................................................9
TECHNICAL INFORMATION......................................................................................................9
SPECIFICATIONS..................................................................................................................9
FEATURES............................................................................................................................10
CONTROLS AND CONNECTIONS............................................................................................10
EXTERNAL CONTROLS ...................................................................................................10
INTERNAL CONTROLS.....................................................................................................12
EQUIPMENT SET-UP....................................................................................................................13
UNPACKING................................................................................................................................13
ANTENNA INFORMATION........................................................................................................13
ANTENNA CONNECTIONS...............................................................................................13
ANTENNA POLARIZATION..............................................................................................14
DISTANCE BETWEEN ANTENNAS.................................................................................14
ANTENNA PLACEMENT...................................................................................................15
IMPROVING RECEPTION/INCREASING RANGE..........................................................16
BTR-300 SET-UP..........................................................................................................................17
LOCATION ............................................................................................................................17
INTERNAL INTERCOM SWITCHES.................................................................................17
RACK MOUNTING..............................................................................................................19
LOCAL HEADSET CONNECTION....................................................................................21
HEADSET MIC SELECT SWITCH.....................................................................................21
TRANSMIT SWITCH................................................................................................... ........21
INTERCONNECTION TO A HARD-WIRED INTERCOM...............................................22
AUXILIARY AUDIO CONNECTION.................................................................................23
POWER CONNECTION................................................................................................... ....23
DUMMY LOAD....................................................................................................................23
TR-300 SET-UP................................................................................................... ..........................24
HEADSET CONNECTION..................................................................................................24
DYNAMIC/ELECTRET MIC SWITCH..............................................................................24
BATTERY INSTALLATION................................................................................................25
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TABLE OF CONTENTS (CONT.)
PRE-WALK-THRU CHECKLIST................................................................................................26
SYSTEM OPERATION..................................................................................................................27
BTR-300 OPERATION................................................................................................... ..............27
POWER ..................................................................................................................................27
LOCAL HEADSET VOLUME.............................................................................................27
PUSH TO TALK/LOCK TO TALK SWITCH......................................................................27
TR-300 OPERATION....................................................................................................................28
POWER ..................................................................................................................................28
BATTERY CHECK................................................................................................... ............28
HEADSET VOLUME................................................................................................... ........28
PUSH TO TALK/PUSH TO TRANSMIT SWITCH............................................................28
BATTERY REMOVAL................................................................................................... ......29
ENABLING AUDIO................................................................................................... ..................30
PORTABLES................................................................................................... ......................30
WIRED INTERCOM................................................................................................... ..........30
AUXILIARY ..........................................................................................................................30
SETTING SYSTEM GAIN LEVELS...........................................................................................31
ADJUSTING GAIN................................................................................................... ............31
BTR-200 BASE STATION................................................................................................... .31
TR-200 PORTABLE..............................................................................................................31
INTERCOM GAIN................................................................................................................32
AUXILIARY GAIN................................................................................................... ............32
SYSTEM WALK-THRU................................................................................................... ..............33
TROUBLE SHOOTING................................................................................................... ..............34
BATTERY INFORMATION..........................................................................................................35
GENERAL................................................................................................... ..................................35
BC-4 BATTERY CHARGER........................................................................................................35
RECOMMENDED HEADSETS................................................................................................... .36
ACCESSORIES................................................................................................... ............................38
WARRANTY SERVICE INFORMATION...................................................................................40
FCC INFORMATION................................................................................................... ..................41
-ii-

INTRODUCTION
GENERAL DESCRIPTION
This manual covers the BTR-300 Base Station
and the TR-300 PortableTransceiver.
The Telex Models BTR-300 and TR-300 were
specificallydesigned to provide the user with a
highly flexible wirelesstwo-way communica-
tion system with the capability ofinterface
with a wired intercom system and other auxil-
iaryaudio.
At the BTR-300 operator’s command, the
remotes maycommunicate with each other,
with a wired intercom system orwith an auxil-
iary system. The BTR-300 Base Station with
itsone transmit and four receive channels was
designed tooperate in full duplex (simulta-
neous two-way communications)with up to
four TR-300 Belt Pack transceivers (one trans-
mitand one receive channel) See block dia-
gram in Figure 1.
Figure 1
Block Diagram of System
-1-

The system operates on selected frequencies
within the 150-216 MHz band.
The BTR-300 system is fully compatible with a
number ofother wired intercom manufacturers
units. See the BTR-300Setup Section for addi-
tional information.
The TR-300 Transceiver operates in the contin-
uous transmitmode with the audio activated by
a switch. As manyas four TR-300 belt-pack
transceivers can operate in a fullyduplex net-
work with one Telex Model BTR-300 Base
Station.
The TR-300P Transceiver operates in the
Push-to-transmitmode (the transmit and talk
function are activatedtogether). Any number
of TR-300P transceivers can be used ina
half-duplex network with one BTR-300 Base
Station. Operate only one TR-300P at a time.
Attemptingto use two transmitters simulta-
neously on the same channelwill cause inter-
ference.
-2-

BTR-300 BASE STATION TRANSCEIVER
TECHNICAL INFORMATION
-3-
SPECIFICATIONS BTR-300
Overall
Input Power.......................................................................13.0 VAC RMS/600 mA with supplied adaptor
or filtered 12 to 14 VDC/600 mA source.
Intercom Output .........50 mV (Low) or 330 mV (Hi) RMS into 300 ohm load typical (at rated deviation)
Intercom Input (Gain Minimum).............................................300 mV RMS typical (for rated deviation)
Auxiliary Output ...........................................430 mV 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 mW maximum output into 600 ohmst
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
Trasmit 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 Telex Model BTR-300 is a Base Station
with onetransmitter and four receivers. It is de-
signed for portabletwo way communication
with the capability for interface toother audio
systems. Features include:
•An extremely flexible unit that has theca-
pability to communicate at one time with
any number of theavailable portable sta-
tions (up to four) or wired stations(inter-
com and/or other audio source).
•Powered by an external AC wall supply
(supplied), via the power jack on the rear of
the unit. Itcan also be powered by any fil-
tered 12 to 14 VDC/600 mAsource or 13.0
VAC RMS 600 mA source.
•Intercom connections with the ability toin-
terface with most wired intercom systems.
•RF LED 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 0.5 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
toturn power ON; push it again to turn the
power OFF.
Power ON Indicator:The Power ON Indica-
tor isilluminated when the Power ON/OFF
Switch is pushed in the ONPosition.
Local Headset Connector:4 Pin XLR Con-
nector forInput/Output. The headset jack will
accept many Telexmodel headsets. Compatible
with other intercomheadsets with four pin
XLR connectors that are wired asshown 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 localheadset microphone audio
function.
NOTE: DOES NOTcontrol base station RF
transmit.
Local Push-to-Talk Indicator: Will be illumi-
nated wheneverthe talk function is on.
Local Microphone Gain Control and
Overmodulation Indicator:A screwdriver
adjustable control is provided to control thein-
put level of the local headset mic. This input is
protected from overloads by means of a gain
compressor whoseoperation is signaled by the
gain LED indicator.
Portable Enable Switches and Indicators:
When in the “IN” position, the Enable switches
allow the user of thecorresponding portable
unit to be heard by others connectedto the sys-
tem. When in the “OUT” position, the respec-
tiveportable will be muted, but this portable
will still be ableto hear all other selected
remotes and interfaces. Theindicators nor-
mally show the presence of a portabletrans-
ceiver in use on the channel corresponding to
thatindicator.
-5-

Ext Intercom Switch, Level Control, and In-
dicator:Thisswitch enables the wired inter-
com interface when “IN”, anddisables it when
“OUT”. For RTS intercoms, the “IN” position
is channel A and the “OUT” position is chan-
nel B. Ascrewdriver adjustable control is pro-
vided to control theinput level of the wired
intercom.
Auxiliary Audio Enable Switch, Level Con-
trol, andIndicator:The switch enables and
disables the Auxiliary interface when “IN” and
“OUT”, respectively. The functionof the level
control here is the same as that described for
the intercom.
REAR PANEL (Refer to Figure 4)
Transmit and Receive Antenna Connectors:
Attach 5/8-wave antenna s (supplied) to these
connectors. Antenna color should match the
connector color dot.
Transmit Switch:Slide switch that allows the
operator toselect one of three transmit modes.
In the “OFF” position,the transmitter is always
off. This mode may be used if thebase is func-
tioning solely as a monitor. In the “CONT”po-
sition, the transmitter is always on. This
continuous mode is recommended over the
“REMOTE” mode. In the “REMOTE” posi-
tion, the transmitter is enabled only when one
or more portables are active.
Headset Microphone Select Switch:This
switch allows theuser to select either an
Electret or Dynamic microphone.
Intercom Connectors:Connections to inter-
face the BTR-300with 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 simplexinput or output.
Typical uses are 4 wire low levelintercom’s,
tape recorders, public address inputs orout-
puts, or when operating two BTR-300 units si-
multaneously.
Power Jack: For external AC wall supply
adaptor (supplied)or any filtered 12 to 14
VDC/600 mA source, or 13.0 VACRMS/600
mA source.
Speaker Jack:Allows the user to connect an
external speaker(8 ohms minimum) to the unit.
Speaker Gain Control:Screwdriver adjust-
able. Adjust thegain control clockwise to in-
crease speaker gain orcounterclockwise to
decrease speaker gain.
NOTE:Leave setting counterclockwise if no
speaker isattached.
-6-

-7-

-8-

TR-300 BELT-PACK TRANSCEIVER
TECHNICAL INFORMATION
-9-
SPECIFICATIONS TR-300
Overall
Power Requirements...................................................................6 AA cells (Alkaline, NEDA, MN 1500)
Nickel Cadmium Optional
Current Drain................................................................................................... .....................typical 65 mA
Temperature Range.....................................................................................-4 oF to 130oF (-20 oC to 55 oC)
Dimensions....................................................................................................4.25" W x 4.125" H x 2.0" D
(108mm x 105mm x 51mm)
Weight................................................................................................................13oz (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, 5000 Hz deviation,
115 micro-seconds Pre-emphasis
Modulation Limiter.....................................................................................................Internal Compressor
Modulation Frequency Range ...............................................................................300 to 5000 Hz +/-2dB
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 Stabiltiy............................................................................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 i sself-contained.
•2 separate antennas, one for transmit, the
other for receive.
•Push-to-Talk with Lock-to-Talk feature
switchfor the TR-300 and Push-to-Transmit
withLock-to-Transmit feature for the
TR-300P.
CONTROLS AND CONNECTIONS
EXTERNALCONTROLS (RefertoFigure 6)
Volume OFF/ON Control:This thumbwheel
control serves asboth an off/on switch and as a
volume control.
Low Battery and Overmodulation
Indicator LED:
Low Battery Indicator : Part of the battery
check circuit. When the power switch is
placed in the “ON”position the LED will
flash one time if the battery is good.A poor
battery will cause the LED to illuminate con-
tinuouslyand a bad or unusable battery will
not cause anyillumination at all.
Overmodulation Indicator:Uses the same
LED asthe low battery indicator. During the
talk mode, if themicrophone gain is too
high, the LED will illuminate whentalking.
Push-To-Talk/Lock-To-TalkSwitch:For
Model TR-300, thisswitch enables the talk
function. For Model TR-300P, thisswitch en-
ables the transmit and audio function and oth-
erwise operates as described for BTR-300.
Talk LED Indicator:(Labeled “talk”) Will be
illuminatedwhenever the talk function on the
TR-300 or transmitfunction on the TR-300P is
enabled.
Headset Jack: A four pin XLR connector for
Input/Output. Theheadset jack will accept
many different Telex model headsets.Compati-
ble with other intercom headsets with four pin
XLRconnectors that are wired as shown in
Figure 5.
Figure 5
Headset XLR Connector Wiring
-10 -

Figure 6
External Controls, TR-300
-11 -

Figure 7
Internal Controls, TR-300
INTERNAL CONTROLS (ReferToFigure 7)
Microphone Gain Control: Screwdriver ad-
justable by removingbelt clip and prying out
the small rubber plug to the rightof the screw
boss.
Dynamic/Electret Switch: This switch allows
selection of “D” when using a Dynamic Micro-
phone or " E" when using anElectret Micro-
phone.
Battery Compartment: Holds 6 AA batteries
in a removablebattery holder (supplied).
-12 -

EQUIPMENT SET-UP
UNPACKING
Unpack your BTR-300 and TR-300 System. If
there are anydamages or shortages, refer to the
“Warranty ServiceInformation" section in this
manual.
ANTENNA INFORMATION
ANTENNA CONNECTIONS
The BTR-300 is supplied with two (2) anten-
nas. One 5/8-waveantenna for Transmit and
one 5/8-wave for Receive.
Assemble the 5/8-wave antenna by screwing
the three sectionsinto one another as shown in
Figure 8. All three sections ofthe BTR-300
5/8-wave antennas must be used. Leaving out a
section will result in reduced distance capabil-
ity.
Figure 8
5/8-wave Antenna Assembly
To insure that the frequency range of the anten-
nas match thereceiver and transmitter of the
BTR-300, match the colorcode on the antenna
with the color code on the BTR-300.
Attach the antennas to the antenna input recep-
tacles. Tighten the connector securely.
Figure 9
Attaching 5/8-wave Antenna
-13 -

ANTENNA POLARIZATION
The Telex Wireless Intercom System is “Verti-
callyPolarized". This means both the transmit-
ting and receivingantennas should operate in
the vertical position.
Figure 10
Vertically Polarized Antennas
The antennas can be remoted for better signal
path. A Telexcoax assembly is required. See
“Accessory” section for orderinformation.
NOTE: If your BTR-300 transceiver is to be
located in ashielded rack mount enclosure or
other poor RF location, youmust remote the
5/8-wave antennas with coax assemblies.
ANTENNA PLACEMENT
Proper antenna placement probably has the
most effect on your TELEX Wireless Intercom
System’s overall performance.The following
suggestions will result in optimumperfor-
mance.
Proper placement of the TR-300 can be critical.
The trailingantennas should “dangle” freely.
“Wadding” the antennas upand placing them
in a pocket, etc., will reduce systemdistance.
It is suggested that the unit be worn on the belt
or pocketwith both antenna’s hung vertically
for best operating rangeand performance.
Figure 11
Proper Dressing of theAntennas
Keep the distance between the base (BTR-300)
and the beltpacks (TR-300) antennas as short
as possible. The greaterthe distance, the
weaker the signal. However, the portables
should be a minimum distance of 10 feet from
the basestation and each other for best perfor-
mance.
Make sure the “signal paths” between the
BTR-300 and remotesare unobstructed. You
should always be able to visiblylocate the an-
tennas for best performance.
Figure 12
Keeping Site Clear to Antenna
-14 -

Attempting to operate the wireless intercom
system throughor around walls, ceilings, metal
objects, etc. will reducesystem range and per-
formance.
SIGNAL REFLECTION OFF AMETAL OBSTRUCTION
CAUSES REDUCED SIGNAL AND“MULTIPATH”
Figure 13
Operating System NearObstructions
DO NOT- mount the BTR-300 5/8-wave an-
tennas on, or next to,metal such as beams,
walls with metal studs, equipmentracks, etc.
This also applies to the antennas when assem-
bleddirectly to the BTR-300. This will “de-
tune” the receivingantenna which can result in
noise or loss of RF signal atthe BTR-300. See
Figure 14.
IMPROVING RECEPTION AND
INCREASING RANGE
Keeping the distance from the base (BTR-300)
and the beltpacks (TR-300) as short , and un-
obstructed as possible willproduce the most re-
liable performance.
The BTR-300 is supplied with two antennas.
This shouldprovide satisfactory system perfor-
mance in mostapplications. System range can
be enhanced by remoting the5/8-wave receive
antenna using the available accessories.
-15 -
1.Placing the unit in an
equipment rack and
remoting the antennas
is GOOD.
2.Placing the unit ontop of
a shelf or equipment
rack unobstructed with-
out remoting the an-
tenna is GOOD.
3.Placing the unit in an
equipment rack with the
antennas mounted on
the BTR-300 is BAD.
Figure 14
BTR-300 Antenna Placement

BTR-300 SET-UP
LOCATION
Locate the BTR-300 transceiver on a level sur-
face with therear of the unit facing you. See
“Antenna Information”section for more infor-
mation on choosing a location.
INTERNAL INTERCOM SWITCHES
Intercom Dip Switch:Located in the inside of
the unit is aDIP Switch. This switch will have
to be set for the wiredintercom unit you will
be using. The switch is factory setfor interfac-
ing with Telex Audiocom wired intercom
units.See Table 1 if you will be using an RTS
or Clearcom wiredintercom system.
To change the switch positions you will need to
remove thecover on the BTR-300. Remove
three #6-32 x 3/8" screws onboth sides of the
unit. Remove four #4-40 x 3/16" screws onthe
top front and loosen three #4-40 x 3/16" screws
on theback of the unit. The cover will lift off.
Reference Figure 15 for switch positions.
Change the switchpositions as indicated in the
chart depending on the wiredintercom system
you will be using. After setting thisswitch, set
the High/Low switch as shown in the next sec-
tionand then replace cover and secure with the
hardwarepreviously removed.
Table 1
Dip Switch Positions For Wired Intercom Terminations
-16 -
Figure 15
Dip Switch
SWITCH POSITION
123456789
Telex AudiocomONONOFFONOFFONOFFOFFON
RTSOFFOFFONOFFONOFFONONOFF
ClearcomONOFFONONOFFOFFOFFONON