Telex BP-325 User manual

9350-5690-00 Rev. L 06/2006
II
I
MODEL BP-325
Belt-pack Intercom Station
User Manual

PROPRIETARY NOTICE
The product information and design disclosed herein were originated by
and are the property of Telex Communications, Inc. Telex reserves all
patent, proprietary design, manufacturing, reproduction, use and sales
rights thereto, and to any article disclosed therein, except to the extent
rights are expressly granted to others.
COPYRIGHT NOTICE
Copyright 2006 by Telex Communications, Inc. All rights reserved.
Reproduction, in whole or in part, without prior written permission from
Telex is prohibited.
WARRANTY NOTICE
See the enclosed warranty card for further details.
CUSTOMER SUPPORT
Technical questions should be directed to:
Customer Service Department
RTS/Telex Communications, Inc.
12000 Portland Avenue South
Burnsville, MN 55337 USA
Telephone: [phone]
Fax: [phone]
Factory Service: 800-553-5992
RETURN SHIPPING INSTRUCTIONS
Customer Service Department
Telex Communications, Inc. (Lincoln, NE)
Telephone: [phone]
Fax: [phone]
Factory Service: 800-553-5992
Please include a note in the box which supplies the company name,
address, phone number, a person to contact regarding the repair, the type
and quantity of equipment, a description of the problem and the serial
number(s).
SHIPPING TO THE MANUFACTURER
All shipments of product should be made via UPS Ground, prepaid (you
may request from Factory Service a different shipment method). Any
shipment upgrades will be paid by the customer. The equipment should
be shipped in the original packing carton. If the original carton is not
available, use any suitable container that is rigid and of adequate size. If
a substitute container is used, the equipment should be wrapped in paper
and surrounded with at least four (4) inches of excelsior or similar
shock-absorbing material. All shipments must be sent to the following
address and must include the Proof of Purchase for warranty repair.
Upon completion of any repair the equipment will be returned via
United Parcel Service or specified shipper, collect.
Factory Service Department
Telex Communications, Inc.
8601 East Cornhusker Hwy.
Lincoln, NE 68507 U.S.A.
Attn: Service
This package should include the following:

TABLE
OF
CONTENTS
Chapter 1 - Connections And Operation
Connections .................................................................................................................................................1
Headset ........................................................................................................................................................1
Intercom Channels ......................................................................................................................................1
Operation .....................................................................................................................................................2
Programmable Options ...............................................................................................................................3
Factory Settings .......................................................................................................................................... 3
Jumpers (W1-w7) ........................................................................................................................................ 4
Sidetone Adjustment ...................................................................................................................................5
Alternate Powering Methods ......................................................................................................................5
General ........................................................................................................................................................5
Method One: One Channel Operation With A Non-rts Power Supply .......................................................5
Method Two: Two Channel Operation With A Non-rts Power Supply .....................................................7
Chapter 2 - Replacement Parts
Where To Obtain Parts ................................................................................................................................9
Electrical Parts ..........................................................................................................................................10
Chapter 3 - Specifications And Drawings
Specifications ............................................................................................................................................16

1
CHAPTER 1
CONNECTIONS AND OPERATION
This section describes operation of the BP325 as supplied from the factory. Use of an RTS power supply to power the intercom
system is assumed. For options and use of an alternate power source (See “PROGRAMMABLE OPTIONS” on page 3. and
See “ALTERNATE POWERING METHODS” on page 5..
CONNECTIONS
Headset
Connect a headset using one of the three headset connectors on the back panel. The MONO HEADSET and STEREO
HEADSET connectors are for monaural or stereo dynamic-mic headsets. The CARB-MIC HEADSET connector is for a
monaural carbon-mic headset. Refer to the specifications for pin-outs of these connectors if needed.
Intercom Channels
Connect the BP325 to the intercom system using the LINE INPUT connector on the back panel.
If desired, connect an additional intercom station to the intercom system using the LINE LOOP connector on the back panel.

CONNECTIONS AND OPERATION
2
OPERATION
1. Attach the BP325 to your belt or other convenient location using the belt clip on the rear panel.
2. Put on the headset and adjust the listen volume controls while listening to the intercom channels.
3. A TALK button may be activated in either of two ways:
Momentary Mode: Press and hold the TALK button, then speak into the microphone. The green talk
LED will remain lit while the TALK button is held. Release the TALK button when finished talking.
The talk LED will turn off.
Latching Mode for Hands-free Conversation: Tap the TALK button (do not press and hold). The
green talk LED will turn on and remain on. When finished talking, tap the TALK button again. The
talk LED will turn off.
4. Calling an intercom channel:
a.Turn on the TALK button for the channel to be called (the green talk LED should be lit).
b.Press and hold the CALL button. The red call LED will light while the button is pressed, indicating
that a call signal is being sent. When a response is heard, release the CALL button and begin your
conversation.
c.Turn off the TALK button when finished with your conversation.
5. Receiving a call:
TAL KTAL K
C A L L
RTS SYSTEMS
BP325 PORTABLE HEADSET STATION
MONO
HEADSET
LINE LOOP
AUX I/O
CARB-MIC
HEADSET
LINE
INPUT
PGM
VOL
STEREO
HEADSET
REMOVE
COVER
4 5
1 2
3
6 7 10b 8 9
10a
10a
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Channel 1 talk button, indicator light and listen
volume control.
Channel 2 talk button, indicator light and listen
volume control.
Call button and indicator light.
Carbon-mic headset jack. May also be used
for external mic switch. See "Programable Options".
Program volume control. Active only when using the
line loop connector for optional program input.
See "Programable Options".
Monaural dynamic-mic headset jack.
Intercom line loop connector for connection to
additional intercom stations. May also be used for
external program input, external mic switch, or a
non-standard power source. See "Programable Options"
and "Alternate Powering Methods".
Intercom line connector. For connection to intercom
system.
Stereo dynamic-mic headset jack.
Rear cover removal to set options:
Loosen two screws (10a) and remove
one screw (10b).

3
FACTORY SETTINGS
a.When there is an incoming call on a channel, the red call LED will flash.
b.If a talk LED is also flashing, this indicates that you need to activate that TALK button to begin
your conversation.
c.If no talk LED is flashing, this indicates that the TALK button is already on; simply begin your con-
versation.
6. Sending a Talk-off Signal: The BP325 can generate an inaudible signal which can be used to deactivate the talk buttons on
other intercom stations connected to an intercom channel. (May be used with models BP325, MCE325 and MRT327). This
feature is useful when an unattended intercom station has its microphone activated and is causing noise on an intercom
channel. To send a talk-off signal:
a.Turn off both TALK buttons on the BP325.
b.Tap the CALL button three quick taps. The red call LED will turn on for about 2 seconds.
c.While the red call LED is on, momentarily press the TALK button for the channel that has the
TALK button to be turned off. This will send the signal and turn off the remote TALK button.
PROGRAMMABLE OPTIONS
Several internal option switches and jumpers can modify the belt pack’s operation. The factory settings are summarized
below. To change any of the factory settings, remove the rear cover screws as shown in Figure 1. Jumper and switch locations
are shown on the label inside the rear cover.
FACTORY SETTINGS
TABLE 1. BP-325 Unit Jumper Settings - This equipment complies with the requirements in Part 15 of the FCC Rules for a
Class A computing device. Operation of this equipment in a residential area may cause unacceptable interference to radio
and TV reception requiring the operator to take whatever steps are necessary to correct the interference.
TRS JACK FUNCTION
EXT
MIC
SW
CARB
MIC
HOST
W7
SW 1 CALL SIGNAL DISABLE
SW 2 MOMENTARY ONLY CH 2
SW 3 TALK 2 DISABLE
SW 4 TALK 1 DISABLE
SW 5 MOMENTARY ONLY CH 1
SW 6 TALK OFF TRANSMIT ENABLE
SW 7 NOT USED
SW 8 TALK OFF RECEIVE ENABLE
12345678
ON
S1
W1
THRU
W4
ON
W4
W3
W2
W1
W5
W5
PGM RIGHT
PGM LEFT
CH 2 LISTEN
CH 1 LISTEN
MONO
STEREO
BAL2
R52
BAL1
R39
MONO 4-PIN
HEADSET
STEREO 5-PIN
HEADSET
INTERCOM
INPUT
INTERCOM
LOOP
PGM INPUT
REMOTE MIC SW/
LOCAL POWER
J2
J3
J7
J6
J4
J5
1
1
1
1
1

CONNECTIONS AND OPERATION
4
Jumpers (W1-W7)
No.
Setting Description
Factory
Default
W1 CH 1 Intercom Audio Listena
a. Listen is factory set to be ON all the time on both
channels. Setting W1 to the OFF position will dis-
able intercom listen audio on channel 1 (usually
the left headphone of a stereo headset). Setting W2
to the OFF position will disable intercom listen
audio on channel 2 (usually the right headphone of
a stereo headset). Listen disable could be used, for
example, when you want to use the left side of a
stereo headphone exclusively for program audio
input and the right side for a single channel of
intercom audio. In this case you would:
1. Set W1 to OFF to disable channel 1 intercom
audio listen to the left headphone.
2. Set DIP switch 4 to ON to disable channel 1
talk.
3. Setup the left channel for program input.
ON
W2 CH 2 Intercom Audio ListenaON
W3 Program input to left headphonebOFF
W4 Program input to right
headphonebOFF
W5 Stereo/Mono operationcStereo
W6 Not Used
W7 CARB/MIC Jack FunctiondHeadset
DIP Switches (S1)
1 Call Signal Transmit Disable OFF
2Momentary Only Talk Button,
CH2eOFF
3CH2 Talk DisablefOFF
4CH1 Talk DisablefOFF
5Momentary Only Talk Button,
CH1eOFF
6Talk-off Transmit enablegON
7 Not Used OFF
8Talk-off Receive Enableh
iON
b. To use program audio input:
1. Unplug the LINE LOOP connector from J6, and
plug it into J5.
2. If you are using a stereo headset, set W3 and/or
W4 to ON to route the program audio to the left
headphone, right headphone or both headphones.
If you are using a mono headset, set both W3 and
W4 to ON.
3. Connect the program source to the LINE LOOP
connector using an XLR-3-32 female receptacle
wired as follows
Pin 1 - Common
Pin 2 - Program input high
Pin 3 - Program input low
4. Adjust program input volume using the PGM
VOL control on the back panel.
c. W5 applies to a stereo dynamic-mic headset con-
nected to the STEREO HEADSET jack. With W5
set in the stereo position, intercom channel 1 will
be heard in the left headphone only, and channel 2
will be heard only in the right. In the mono posi-
tion, both intercom channels (and program audio if
connected) will be heard in both headphones. If
you are using monaural headphones connected to
the MONO HEADSET jack, W5 may be left in the
stereo position.
d. The CARB-MIC connector may be used to con-
nect either a headset or an external mic ON/OFF
switch. (If you are using a carbon-mic headset, but
still wish to use an external mic switch, the LINE
LOOP connector may alternatively be used for the
mic switch. See note X, below.) To use the CARB-
MIC connector for an external mic ON/OFF
switch:
1. Place jumper W7 in the “EXT MIC SW” posi-
tion.
2. Use a stereo phone plug to connect the external
switch to the CARB-MIC HEADSET jack:
Tip: Remote Mic Switch Normal-open
Contact
Ring: No connection
Sleeve: Remote Mic Switch Common
3. To use the external mic switch, first set one or
both TALK buttons to the latched-on position.
Then, press the external mic switched turn the
TALK button(s) ON. Release the mic switch to
turn the TALK button(s) OFF. Note, the TALK
buttons may still be turned ON or OFF from the
BP-325; however, the external mic switch will not
work unless the TALK buttons are first turned ON
at the BP-325

CONNECTIONS AND OPERATION
5
SIDETONE ADJUSTMENT
You can change the level of your own voice heard in your
headphones while talking on an intercom channel. Adjust
R39 to change your voice level when talking on channel 1.
Adjust R52 to change your voice level when talking on
channel 2.
ALTERNATE POWERING
METHODS
GENERAL
When using an RTS power supply to power the intercom
system, power is carried to the BP325 on pin 2 of the LINE
INPUT connector along with the channel 1 audio. Pin 1 is
the DC return. The unique design of RTS power supplies
permits power to be carried on an audio channel. RTS power
supplies also provide the proper terminating impedance for
each intercom channel. If a non-RTS power supply is used,
there are two alternatives for connecting power and intercom
audio.
The first method uses channel 1 only to connect the non-RTS
power supply. Audio on channel 1 will be unusable as the
power supply will look like a short circuit at audio
frequencies. Channel 2, however, will still be operational.
Also, channel 2 will require a terminating impedance, since
this is not supplied by the non-RTS power supply.
The second method allows the use of a non-RTS power
supply while still maintaining two audio channels. This
method requires an additional wire to the belt pack, and the
LINE LOOP connector will not be usable for connecting
another intercom station. Also, each intercom channel must
be properly terminated. The two methods are discussed
below.
METHOD ONE: ONE CHANNEL OPERATION
WITH A NON-RTS POWER SUPPLY
Using an XLR-3-32 female connector, connect the external
power source and the channel terminating components to the
LINE INPUT connector as
shown in Figure 2.
If desired, the LINE LOOP connector may be
used to connect power and audio to an additional
intercom station.
e. As supplied, the TALK buttons feature a dual-
action momentary/latching operation: press and
hold for momentary talk, then release when fin-
ished; or tap to latch ON for hands-free talk, and
tap again to turn OFF when finished talking. If
desired, the latching operation may be defeated,
and the TALK buttons may be operated in momen-
tary mode only.
f. Setting DIP switch 3 to the ON position will dis-
able the channel 2 TALK button. Setting DIP
switch 4 to the ON position will disable the chan-
nel 1 TALK button.
g. As supplied, the BP-325 can generate an inaudible
talk-off signal which can be used to deactivate the
talk buttons on other intercom stations connected
to an intercom channel. To turn this feature OFF,
set DIP switch 6 to the OFF position.
h. As supplied, other intercom stations can deactivate
the TALK buttons on the BP-325 using the Talk-
Off feature from their intercom stations. To disable
this feature, set DIP switch 8 in the OFF position.
i. Using the LINE LOOP connector for an external
mic ON/OFF switch:
1. Unplug the LINE LOOP connector from J6 on
the circuit board, and plug it into J4.
2. Connect the external mic switch to the LINE
LOOP connector using an SLR-3-32 female recep-
tacle wired as follows:
Pin 1: Remote Mic Switch Common
Pin 2: No Connection
Pin 3: Remote Mic Switch
Normal-open Contact
3. To use the external mic switch, first set one or
both TALK buttons to the latched-ON position.
Then, press the external mic switch to turn ON the
TALK button(s). Release the mic switch to turn off
the TALK button(s). Note, the TALK buttons may
still be turned ON or OFF from the BP-325; how-
ever, the external mic switch will not work unless
the TALK buttons are first turned on at the BP-
325.

CONNECTIONS AND OPERATION
6
FIGURE 1. LINE INPUT Connector Wiring for 1-Channel
Operation with Non-RTS Power Supply
FIGURE 2. Bottom View of the Main Circuit Board
FIGURE 3. LINE LOOP Connector Wiring for 2-Channel
Operation with Non-RTS Power Supply.
200 Ohms
+
Pin 1, Common
10mF /50V
Pin3,Ch2+Audio
Pin 2, +18 TO +24 VDC
TO BP325
LINE INPUT TO INTERCOM
CHANNELS AND
POWER SUPPLY
CUT
TRACE
Pin 1
Pin 2
Pin 3
+18to+24VDC
Common
No Connection
FIGURE 4. LINE INPUT Connector Wiring for 2-Channel Operation with Non-RTS Power Supply
200 Ohms
+
Pin 1, Common
200 Ohms
+
10mF /50V 10mF /50V
Pin3,Ch2+Audio
Pin2,Ch1+Audio
TO BP325
LINE INPUT TO INTERCOM
CHANNELS
OPTIONAL CONNECTOR
TO ADDITIONAL
INTERCOM STATION
LINE INPUT

CONNECTIONS AND OPERATION
7
METHOD TWO: TWO CHANNEL OPERATION
WITH A NON-RTS POWER SUPPLY
1. Referring to Figure 1, remove all three screws (10a and
10b) on the back connector panel of the BP325. Remove
the rear cover/belt clip assembly.
2. There are two connectors that connect the main circuit
board to the front panel circuit board. Pry the tabs on
these two connectors to disconnect them. Remove the
back connector panel and main circuit board from the belt
pack.
3. On the bottom side of the main circuit board, cut the trace
as shown in Figure 3.
4. Reassemble the main circuit board and rear connector
panel to the belt pack.
Note: If the rear connector panel becomes separated from
the main circuit board at any time, make sure that
the shaft of the program volume control knob inserts
into the program volume control potentiometer on
the main circuit board during reassembly.
5. Referring to the label on the inside of the rear cover,
unplug the LINE LOOP connector from J6 and plug it
into J4.
6. Reassemble the rear cover.
7. Using an XLR-3-32 female receptacle, connect the
external power source to the LINE LOOP connector as
shown in Figure 4. Connect +DC to pin 2 and connect
power supply common to pin 1.
Using an XLR-3-32 male plug, connect intercom channels
and termination components as shown in Figure 5. Plug this
connector into the LINE INPUT jack of the BP325.

CONNECTIONS AND OPERATION
8

9
CHAPTER 2
REPLACEMENT PARTS
WHERE TO OBTAIN PARTS
Parts may be obtained directly from RTS at:
TELEX/RTS SYSTEMS
Attn: Factory Service
8601 East Cornhusker Hwy.
Lincoln, NE 68507 U.S.A.

REPLACEMENT PARTS
10
MECHANICAL PARTS
(Reference AS3233 Drawing)
ELECTRICAL PARTS
Final Assembly
(Refer to AS6738 Drawing for Item No. locations)
Item
No. Qty Description RTS Part No.
1 1 Front/ Top Panel Assy 9020673700
2 1 Rear Panel Assy 9020673600
4 1 Bottom Case with Clip 9020563500
6 3 Screw, #4-40 X 3/4” 1008407600
7 1 Label, Programming Instr 9170684200
8 1 Knob, Program Volume 9160677500
10 1 Label, Belt Clip 9170688400
11 1 Label, Serial Number 3101001700
Front/Top Panel Assy
(Refer to AS6737 Drawing for Item No. locations)
Item
No. Qty Description
RTS Part
No.
1 1 Front Case 9020563601
21
Front Panel Circuit Board
Assy 9030663400
3 1 Main Circuit Board Assy 9030663500
4 3 Screw, #4-40 X 3/8” 51856035
5 1 Button, Talk CH 1 9160563603
6 1 Button, Talk CH 2 9160563604
7 1 Button, Call 9160563605
8 1 Lens, Call 9150563606
9 2 Knob 9160563602
10 2 Knob Body, Nylon 9160563601
11 6 Jumper, E-Cam 282-11-10 2515001500
12 2 Pushnut Fastener 1005021100
Rear Panel Assy
(Refer to AS6736 Drawing for Item No. locations)
Item
No. Qty Description RTS Part No.
1 1 Rear Panel 9080563700
21
Connector, Male insert, 3-
pin 2018006900
31
Connector, Female insert,
4-pin (3 pcs) (includes
items 7 & 8)
2019001900
41
Connector, Female insert,
5-pin (3 pcs) (includes
items 7 & 8)
2019002000
51
Connector, Female insert,
3-pin (3 pcs) (includes
items 7 & 8) 2019002100
73
Latch (included with items
3-5) 1005017700
83
Spring, (included with
items 3-5) 1005017600
9 3 Release Lever 9160563701
10 2 Housing, 3-pin 59958003
11 2 Housing, 6-pin 59958006
12 15 Crimp Connector (for
items 10 and 11) 59958200
Electrical Parts
Main Circuit Board
Ref
No. Description
RTS Part
No.
C1 Capacitor, EL, SM, 47 UF, 10V 102884215
T
C2 Capacitor, CM, SM, 10 PF, 50V 102879204
T
C3 Capacitor, EL, SM, 47 UF, 10V 102884215
T
C4,
C5 Capacitor, CM, SM, 1000 PF, 50V 102884216 T
C6 -
C8 Capacitor, CM, SM, 0.1 UF, 50V 102880226 T
C9 Capacitor, EL, SM, 47 UF, 10V 102884215
T
C10 Capacitor, CM, SM, 470 PF, 50V 102879212
T
C11 Capacitor, CM, SM, 0.1 UF, 50V 102880226
T
C12 Capacitor, EL, SM, 22 UF, 35V 1099R2263
GT
C13 Capacitor, CM, SM, 0.01 UF, 50V 102881339
T
C14 Capacitor, CM. SM, 1000 PF, 50V 102879216
T
Rear Panel Assy
(Refer to AS6736 Drawing for Item No. locations)
Item
No. Qty Description RTS Part No.

REPLACEMENT PARTS
11
C15 Capacitor, CM, SM, 10 PF, 50V 102879271T
C16 Capacitor, EL, SM, 1 UF, 50V 102884606
T
C17 Capacitor, CM, SM, 0.1 UF, 50V 102880226
T
C18 -
C20 Capacitor, CM, SM, 10 PF, 50V 102879204 T
C21 Capacitor, CM, SM, 10 PF, 50V 102879271T
C22 -
C24 Capacitor, EL, SM, 22 UF, 35V 1099R2263 GT
C25 Capacitor, CM, SM, 10 PF, 50V 102879204
T
C26 Capacitor, EL, SM, 22 UF, 35V 1099R2263
GT
C27,
C28 Capacitor, CM. SM, 10 PF, 50V 102879204 T
C29 Capacitor, CM, SM, 10 PF, 50V 102879271T
C30 -
C32 Capacitor, EL, SM, 22 UF, 35V 1099R2263
GT
C33 Capacitor, CM. SM, 10 PF, 50V 102879204
T
C34,
C35 Capacitor, EL, XM, 1 UF, 50V 102884606
T
C36,
C37 Capacitor, CM, SM, 1000 PF, 50V 102879216
T
C38 Capacitor, EL, SM, 1 UF, 50V 102884606
T
C39 Capacitor, CM, SM, 10 PF, 50V 10287927T
C40 Capacitor, EL, SM, 47 UF, 10V 102884215
T
C41 Capacitor, EL, RAD, 2200 UF, 16V 1502R2284
E
C42,
C43 Capacitor, EL, SM, 47 UF, 10V 102884215 T
C44,
C45 Capacitor, CM, SM, 0.1 UF, 50V 102880226 T
C46 Capacitor, EL, SM, 22 UF, 35V 1099R2263
GT
C100,
C101 Capacitor, EL, SM, 1 UF, 50V 102884606
T
C102,
C103 Capacitor, CM, SM, 10 PF, 50V 102879271T
C104, Capacitor, CM. SM, 10 PF, 50V 102879204
T
C105 Capacitor, CM, SM, 10 PF, 50V 102879271T
C106 Capacitor, CM, SM, 0.1 UF, 50V 102880226
T
C107 Capacitor, CM, SM, 1000 PF, 50V 102879216
T
Electrical Parts
Main Circuit Board
Ref
No. Description
RTS Part
No.
C108,
C109 Capacitor, CM, SM, 0.1 UF, 50V 102880226
T
C110 Capacitor, EL, SM, 47 UF, 10V 102884215
T
C111 Capacitor, CM SM, 0.1 UF, 50V 102880226
T
C112 Capacitor, CM, SM, 1000 PF, 50V 102879216
T
C113,
C114 Capacitor, CM, SM, 0.1 UF, 50V 102880226
T
C115 Capacitor, EL, SM, 47 UF, 10V 102684215
T
C116,
C117 Capacitor, EL, SM, 1 UF, 50V 102684606
T
CC1 -
CC7 Capacitor, CM, SM, 0.1 UF, 50V 102880226
T
CC10
-
CC14
Capacitor, CM, SM, 0.1 UF, 50V 102880226
T
D1 -
D3 Diode, SM, Switching, BAV70 102252000 T
D4,
D5 Diode, 1N6481 16016481S MT
D6 Diode, Suppressor, ISMC33A 16010004S
MT
D7 -
D13 Diode, SM, Switching, BAV70 102252000 T
D101
-
D103
Diode, SM, Switching, BAV70 59180303
FB1,
FB2 #73 Shield Bead 59180303
J1 Jack, PC, MT, 3/8”H 2013004900
J2, J3 Header, 6-Pin 59958106
J4 - J7 Header, 3-Pin 59958103
J8, J9 Connector, 6-Position, JST FJ-6P 20070143S
M
Q1 Transistor, FET, SST5484 16025484S
MT
Q2,
Q3
Transistor, SM, SI NPN,
MMBT5088
102210000
T
Q10 Transistor, FET MMBT5087 16025087S
MT
Q11 Transistor, SM, SI NPN,
MMBT5088
102210000
T
Q12 -
Q14 Transistor, FET, MMBT5087 16025087S
MT
Q15 Transistor, SM, SI NPN,
MMBT5088
102210000
T
Electrical Parts
Main Circuit Board
Ref
No. Description
RTS Part
No.

REPLACEMENT PARTS
12
R1,
R2 Resistor, SM, 22K Ohm, 5%, 1/8W 102513223
T
R3 Resistor, SM, 1K Ohm, 5%, 1/8W 102513102
T
R4 Resistor, SM, 301 Ohm, 1%, 1/8W 102404146
T
R5 Resistor, SM, 3.01K Ohm, 1%, 1/
8W
102404246
T
R6 Testor, SM, 301 Ohm, 1%, 1/8W 102404146
T
R7 Resistor, SM, 3.01K Ohm, 1%, 1/
8W
102404246
T
R8 Resistor, SM, 1K Ohm, 5%, 1/8W 102513102
T
R9,
R10 Resistor, SM, 620 Ohm, 5%, 1/8W 102513621T
R11 Resistor, SM, 100K Ohm, 5%, 1/
8W
102513104
T
R12,
R13 Resistor, SM, 22 Ohm, 5%, 1/8W 102513220
T
R14 Resistor, SM, 22K Ohm, 5%, 1/8W 102513223
T
R15 -
R17
Resistor, SM, 5.1mg Ohm, 5%, 1/
8W
102513515
T
R18 Resistor, SM, 200 Ohm, 5%m 1/8W 102513201T
R19 Resistor, SM, 100K Ohm, 5%, 1/
8W
102513104
T
R20 Resistor, SM, 22K Ohm, 5%, 1/8W 102513223
T
R21 Resistor, SM, 100K Ohm, 5%, 1/
8W
102513104
T
R22 Resistor, SM, 22K Ohm, 5%, 1/8W 102513223
T
R23 Resistor, SM, 100K Ohm 5%, 1/8W 102513104
T
R24 Resistor, SM, 15K Ohm, 5%, 1/8W 102513153
T
R25 Resistor, SM, 10K Ohm, 5%, 1/8W 102513103
T
R26 Resistor, SM, 200 Ohm, 5%, 1/8W 102513201T
R27 Resistor, SM, 100 Ohm, 5%, 1/8W 102513101T
R28 Resistor, SM, 100K Ohm, 5%, 1/
8W
102513104
T
R29 Resistor, SM, 1K Ohm, 5%, 1/8W 102513102
T
R30 Resistor, SM, 10K Ohm, 5%, 1/8W 102513103
T
R31 Resistor, SM, 1K Ohm, 5%, 1/8W 102513102
T
Electrical Parts
Main Circuit Board
Ref
No. Description
RTS Part
No.
R32 Resistor, SM, 220K Ohm, 5%, 1/
8W
102513274
T
R33 Resistor, SM, 1K Ohm, 5%, 1/8W 102513102
T
R34 Resistor, SM, 22K Ohm, 5%, 1/8W 102513223
T
R35 Resistor, SM 68K Ohm, 5%, 1/8W 102513683
T
R36 -
R38 Resistor, SM. 22K Ohm, 5%, 1/8W 102513223
T
R39 Potentiometer, Linear, 10K Ohm,
25%, 0.1W
14090065S
MT
R40,
R41
Resistor, SM, 60.4K Ohm, 1%, 1/
8W
102404375
T
R42,
R43 Resistor, SM, 20K Ohm, 1%, 1/8W 102404329
T
R44 Resistor, SM, 100 Ohm, 5%, 1/8W 102513101T
R45 Resistor, SM, 100K Ohm, 5%, 1/
8W
102513104
T
R46 Resistor, SM, 22K Ohm, 5%,1/8W 102513223
T
R47 Resistor, SM, 68K Ohm, 5%, 1/8W 102513683
T
R48 Resistor, SM, 22K Ohm, 5% 1/8W 102513223
T
R49 Resistor, SM, 1K Ohm, 5%, 1/8W 102513102
T
R50,
R51 Resistor, SM, 22K Ohm, 5%, 1/8W 102513223 T
R52 Potentiometer, Linear, 10K Ohm,
25%, 0.1W
14090065S
MT
R53,
R54
Resistor, SM, 60.4K Ohm, 1% 1/
8W
102404375
T
R55,
R56 Resistor, SM, 20K Ohm, 1%, 1/8W 102404329 T
R57 Resistor, SM, 100 Ohm, 5%, 1/8W 102513101T
R58 -
R60
Resistor, SM, 100K Ohm, 5%, 1/
8W
102513104
T
R61 Resistor, SM, 60.4K Ohm, 1%, 1/
8W
102404375
T
R62 Resistor, SM, 10K Ohm, 1%, 1/8W 102404300
T
R63 Resistor, SM, 60.4K Ohm, 1%, 1/
8W
102404375
T
R64 Resistor, SM, 10K Ohm, 1%, 1/8W 102404300
T
R65 Trimpot, 50K 1412100601
R66 Resistor, SM, 10K Ohm, 5%, 1/8W 102513103
T
Electrical Parts
Main Circuit Board
Ref
No. Description
RTS Part
No.

REPLACEMENT PARTS
13
R67 Resistor, SM, 100K Ohm, 5%, 1/
8W
102513104
T
R68 Resistor, SM, 10K Ohm, 5%, 1/8W 102513103
T
R69 Resistor, SM, 2.7 Ohm, 5%, 1/8W 1025132R7
T
R70 Resistor, SM, 10K Ohm, 5%, 1/8W 102513103
T
R71 Resistor, SM, 1.1K Ohm, 5%, 1/8W 102513112
T
R72 Resistor, SM, 30 Ohm, 5%, 1/8W 102513300
T
R73 -
R76 Resistor, SM, 22K Ohm, 5%, 1/8W 102513223
T
R77 Resistor, SM, 200 Ohm, 5%, 1/8W 102513201T
R78,
R79
Resistor, SM, 100K Ohm, 5%, 1/
8W
102513104
T
R80 Resistor, SM, 22 ohm, 5%, 1/8W 102513220
T
R81 Resistor, SM, 30 Ohm, 5%, 1/8W 102513300
T
R82 -
R84 Resistor, SM, 22K Ohm, 5%, 1/8W 102513223 T
R85 Resistor, SM, 100K Ohm, 5%, 1/
8W
102513104
T
R101
-
R104
Resistor, SM, 100K Ohm, 5%, 1/
8W
102513104
T
R105 Resistor, SM, 270K Ohm, 5%, 1/
8W
102513274
T
R106 Resistor, SM 22K Ohm, 5%, 1/8W 102513223
T
R107 Resistor, SM, 270K Ohm, 5%, 1/
8W
102513274
T
R108
- R111 Resistor, SM, 22K Ohm, 5%, 1/8W 102513223
T
R112 Resistor, SM, 2.2mg Ohm, 5%, 1/
8W
102513225
T
R113
-
R115
Resistor, SM, 270K, Ohm, 5%, 1/
8W
102513274
T
R116
-
R118
Resistor, SM, 470K Ohm, 5%, 1/
8W
102513474
T
R119
-
R121
Resistor, SM, 47K Ohm, 5%1/8W 102513473
T
R122 Resistor, SM, 3K Ohm, 5%, 1/8W 102513302
T
Electrical Parts
Main Circuit Board
Ref
No. Description
RTS Part
No.
R123 Resistor, SM, 39 Ohm, 5%, 1/8W 102513390
T
R124 Resistor, SM, 22K Ohm, 5%, 1/8W 102513223
T
R125 Resistor, SM, 47K Ohm, 5%, 1/8W 102513473
T
R126 Resistor, SM, 22K Ohm, 5%, 1/8W 102513223
T
R127 Resistor, SM, 47K Ohm, 5%, 1/8W 102513473
T
R128 Resistor, SM 2.7 Ohm, 5%, 1/8W 1025132R7
T
R129 Resistor, SM, 22K Ohm, 5%, 1/8W 102513223
T
R130 Resistor, SM, 2.7 Ohm, 5%, 1/8W 1025132R7
T
R131 Resistor, SM, 22K Ohm, 5%, 1/8W 102513223
T
R132
-
R136
Resistor, SM, 22K Ohm, 5%, 1/8W 102513223
T
RP1,
RP2
Resistor, Network, 22K Ohm X 9,
Pin 1 COM, 1.5W 1411220200
RR1 -
RR6 Resistor, SM, 22 Ohm, 5%, 1/8W 102513220 T
Ss1 Switch, DIP, Low Profile 19090002S
MS
U1 IC, Dual Op Amp, LM833 16030833S
MT
U2 IC, Analog Switch, 4053B 53266123S
U3,
U4
IC, SM, LP JFET Input Op Amp,
TL062
16030131S
MS
U5 IC, SM , Dual Op Amp, MC34072 16030140S
MS
U6,
U7
IC, SM, LP JFET Input Op Amp,
TL062
16030131S
MS
U8 IC, Voltage Regulator, LM317 53290000
U10 IC, SM, Adj Micropower VREG,
LP2951CM 59631000S
U11 IC, Quad Schmidt 2 Input NAND,
4094B 53266124
U12 IC, HD63701VOCP 1603014400
S
U13,
U14 IC, Op Amp, National LM386N-1 53281100
U15 IC, SM, DARL Trans Array,
ULN2004
16030008S
MS
Y100 Crystal, 4 mHz, Fox FPX-SM-
4.00M
33010009S
M
Electrical Parts
Main Circuit Board
Ref
No. Description
RTS Part
No.

REPLACEMENT PARTS
14
Connector, St Header, 0.100, M3 2007009900
Trimpot Shaft 2703002900
Heatsink 4502001600
Screw, 4-40 X 1/4” pan head
phillips 1008402300
Nut, 4-40 special, small pattern 1007000700
Washer, 4-40 compression 1006004100
Front Panel Circuit Board
Ref
No. Description Part No.
DS1,
DS2 LED, Yellow 1801575100
DS3 LED, Red 1801002000
J8, J9 Connector, 6-Pin 2007014400
R1, R2 Pot, 10K, Audio 1406003901
S1 -
S3 Switch, Momentary Keyboard 545094001
Key Cap Extension 701635000
Electrical Parts
Main Circuit Board
Ref
No. Description
RTS Part
No.

15
CHAPTER 3
Specifications and Drawings
Drawing Number Title
9030-6634-000 Front Panel Circuit Board Component Layout
9030-6635-000 Main Circuit Board Component Layout
AS6736 Rear Panel Assembly
AS6737 Front/Top Panel Assembly
AS6738 Final Assembly
SD6634 Schematic Diagram, Front Panel Circuit Board
SD6635 Schematic Diagram, Main Circuit Board

Specifications and Drawings
16
Specifications
Dimensions
5.00” High x 3.75” Wide x 2.05” Deep
(127mm x 96.3mm x 52.1mm)
Weight
0.5 pounds (225 grams)
Exterior
Polystyrene and polycarbonate mix; gray textured main body
Power Requirements
Input DC Voltage
=18 to +35 volts DC, operating; -200 to +36 volts DC
without damage
DC Current
mA
Average talk + call light: 6 No Signal: 27 milliamperes.
Average talk (25 ohm headphones, 10dB below clipping): 43
0mA
Impedance Across Intercom Line
10,000 ohms typical
Ambient Temperature Range
Operating: 0°C to 50°C (32°F - 122°F)
Storage: -40°C to 125°C (-40°F to 257°F)
Noise Contribution to 200-Ohm Intercom Line
-75 dBu
Headphone Amplifier
Maximum Voltage Gain: 30dB
Frequency Response: 100 Hz to 8 kHz,
+/-3 dB
Headphone Impedance: 50 to 600 ohms
Output Power: 150 mW/50 ohms
Output Voltage Level: 8 volt peak-to-peak
Microphone Preamplifier
Maximum Voltage Gain: 54 dB
Frequency Response: 100 Hz to 8 kHz,
+/-3 dB
Input Impedance: 1,000 ohms, balanced
Limiter Range: 30 dB
Program Input
Maximum Input Level: +20 dBu
Nominal Input Level: -10 to +8 dBu
Frequency Response: 100 Hz to 12 kHz,
+/-3 dB
Monaural Dynamic-mic Headset Connector
XLR-4-31 receptacle (J13)
Pin 1 - Microphone low
Pin 2 - Microphone high
Pin 3 - Common
Pin 4 - Headphone high
Stereo Dynamic-mic Headset Connector
XLR-5-31 receptacle (J14)
Pin 1 - Microphone low
Pin 2 - Microphone high
Pin 3 - Common
Pin 4 - Headphone left high
Pin 5 - Headphone right high
Carbon-mic Headset Connector (J1) - 1/4 inch, 3-conductor
Phone Jack
Used for Headset
Tip - Carbon microphone
Ring - Headphone