Bogen 15-1 Service Manual

BOGEN

A DIVISION OF LEAR SIEGLER, INC.

MCT-1

SERIES 15

DESCRIPTION

The

Bogen

Series 15-1 Centralized School Sound
System is designed to serve up to 50 rooms. It incorpo­rates one Model MCT-1 Control Center and either one
or two Model SBS-25 Switchbanks, and is housed in a

desk-top consolette. The Series
to 25 rooms and includes one Control Center, one
Switchbank and one Model TP-160B AM/FM Tuner
housed in a desk-top consolette. The Series 15-2 consists
of one Control Center, one or two Switchbanks, one
AM/FM Tuner and one BSR 3-speed record changer. It
is housed in a desk-top, dual consolette and serves up to
50 rooms. The Series 15-3 consists of one Control
Center, one or two Switchbanks, one AM/FM Tuner
and one 3-speed record changer. It can accommodate up
to 50 rooms and is operated from a sturdy free-standing
console.

Each system has one 35-watt program channel and an
independent 4-watt intercom channel. The program
channel has two low-impedance microphone inputs
which can be used balanced or unbalanced. It also has
inputs for radio, phono and tape program sources and a
fader control to select either radio or phono-tape. The
selected program may be used alone or may be mixed
with the microphone program.

The MCT-1 control panel has a loudspeaker which
serves as both a program monitor speaker and an inter­com transmitter/receiver. By means of the intercom
channel, the operator may hold a two-way conversation
with occupants of any room without disturbing the pro­gram being transmitted to other rooms. If desired, the
intercom channel also may be used to permit the op­erator to monitor any selected room through its room
speaker.

15T-

1 accommodates up

MODELS

15T-1,15-2,15-3

Model 15-2

In addition to the control panel, each Series 15
solette or console has one or two switchbanks contain­ing the individual room selector switches. In the stan­dard system, these are 3-position lever switches used to
connect each room speaker to either the program (A)
channel or the intercom (C) channel, or to disconnect
the speaker from the system (Systems with optional
light-annunciator call circuit have four-position lever
switches). The units have an Emergency mode of opera­tion which overrides these selector switches. When
operating in Emergency, the operator can transmit from
the control panel speaker to all room speakers, regard­less of the settings of the room selector switches or of
other program inputs to the speakers. The Emergency
function operates whether the power switch is on or off.

INSTALLATION

UNPACKING

Inspect the shipping container and unit for indica­tions of improper handling. The unit was carefully
checked before leaving the factory. If the unit has been
damaged, make an
tributor from whom it was purchased. If the unit was
shipped to you, notify the transport company without
delay and place your claim.

immediate

claim to the dealer or dis-

15-1,

con-

Printed in USA

8005

CENTRALIZED SCHOOL SOUND SYSTEM

54-5665-04

LOCATION OF

CONSOLE/CONSOLETTE

Where possible locate the console centrally, relative
to the rooms being served, in order to minimize the
length of speaker cables. The rear of the unit must
remain accessible for maintenance and for changing in­put and output connections. It is advisable that the unit
be oriented in such a manner that the operator, program
director and other interested parties are able to observe
the controls at all times. Provide adequate lighting and
ventilation. Do not locate the unit close to heat sources,
such as radiators and warm-air ducts, or against a wall
which prevents proper ventilation.

The Series 15-1 and

15T-1

consolettes are 21¼” (54

cm.) wide x 16” (40.6 cm.) high x 16” deep. The Series

15-2 consolette is 40½” (102.9 cm.) wide x 16” high x
16” deep. The Series 15-3 console is 22” (55.9 cm.) wide

x 46” (116.8 cm.) high x 31” (78.7 cm.) deep.

POWER

Connect the 3-wire cord with ground to a

50/60

Hz source. Make certain that the ground terminal

of the power receptacle connects to earth ground.

Two 50W AC power receptacles are provided on the
rear panel for a tuner, automatic record changer or aux­iliary equipment. Line voltage is applied to these com­ponents when the consolette or console power switch is
on. Plug AC line cords into appropriate receptacle.

105-125V,

INPUT CONNECTIONS

MICROPHONE INPUTS. Two terminal strips on

the rear of the MCT-1 provide for two low impedance
balanced or unbalanced microphone inputs.
conductor shielded microphone cable should be used
(Bogen #l008

or equivalent). Connect shield to terminal

1.

Two-

TUNER/PHONO-TAPE INPUTS. Two jacks accept

single-conductor shielded cable.

TAPE RECORDER/BOOSTER AMP INPUT. Ac-

cepts a two-conductor shielded cable

(Bogen

BB 8450 or

equivalent).

INTERCOM CALL-IN LINE. Connect parallel lines

from station call-in switches with 2-conductor shielded

cable. Connect shield to terminal 3.

SWITCHBANK

CONNECTION. Eleven-pin plug
connects three shielded pairs plus annunciator wire
from a switchbank. Also accommodates three lines for
optional telephone system.

TIME CLOCK INPUT. Terminal strip connects a
single-circuit time clock, closing contacts to activate the
optional Model SST-l Module.

GENERAL WIRING

RUNNING CABLES

WIRES. Class II wiring may be used for all audio and
annunciator lines. Make certain to properly support
cables to prevent sagging or strain. Keep wires clear of
objects which would subject them to heat, friction, or
other abuse.

Use No. 20 AWG shielded pairs with insulated outer

jacket (Bogen BB-8450, or equivalent) for speaker lines.

Annunciator lines require a third wire, which usually is
No. 22 AWG insulated wire with red insulation (Belden
8937, or equivalent). The number and types of wires
running from each room to the consolette and running
inside the classroom depend upon the type of speaker
operation required. Consult Table I for the wires re­quired in your particular system.

TABLE I. CABLE RUNNING CHART FOR SERIES 15

Wires from Room to Consolette

Type of Classroom Switch or Device

Used with Speaker

None (Speaker Only)
Call (Model

CA-l0)
Call/Privacy (Model CA-l 1)
Voice Call-In, Non-Private

(Model CA13)

*Alternate method:

Run

two cables from room nearest consolette and one cable from each remaining room. Run

one cable in a loop or branch circuit connecting all room switches.

Shielded Pair

(Jacketed)

(Bogen

BB-8450)

1

1

1

2* 0

-2-

No. 22 AWG

Single

Conductor

(Belden

8937)

0
1 1
1 1

Wires From Room Switch

to Room Speaker

Shielded Pair

(Jacketed)

(Bogen BB-8450)

0

1

Refer to

Figure

2, 7

OUTLET BOXES. Where flush-mounting switches
are used, single-gang outlet boxes will be installed. In
installing such boxes, make certain to place them in a
location that permits personnel to operate the switch
while communicating via the room speaker. The normal
height (above the finished floor) for room switches is
approximately four feet, while speakers are normally
placed at a height of about seven and one-half feet.

CLASSROOM WIRING

CONNECTIONS

Refer to the left-hand column of Table I for the type
of classroom operation used in your system. The corres­ponding right-hand column calls out the wiring diagram
required. Solder the wires as shown in the proper dia­gram and wrap with insulating tape.

SOLDERING INSTRUCTIONS

SOLDER.
Make all solder connections with standard
core radio solder. Do not apply excessive heat. Solder­ing irons or guns from 75 to 200 watts will provide
ample capacity.

GROUNDS.

ground or to convenient metal objects.

connect cable shields only as shown in the wiring
diagrams.

SPEAKER TRANSFORMER

Do not use acid-core solder or acid paste.

60/40 resin-

Do not connect cable shields to earth

It

is important to

BOGEN

ROOM

25-VOLT

LINE MATCHING

(SEE NOTE-P)

CAUTION

Make certain to connect

all

wires in accor­dance with the color codes given on the dia­gram.

SECURING SWITCHES

The Model CA switches are designed for flush

mounting in a standard single-gang electrical outlet box,

BOGEN 25-VOLT

ROOM

SPEAKER TRANSFORMER

LINE MATCHING

(SEE

NOTE-2)

(SEE NOTE-I)

--

I

22AWG MIN.(TYP.)

(BELDEN 8937, OR

TO CONSOLE ‘SWITCH BANK

NOTES :
I- CONNECT AS FOR NON-PRIVATE OPERATION, AS FOR NON-PRIVATE WITH ANNUNCIATOR,

OR AS

2-

MODEL

AND ADDITIONAL INFORMATION.

FOR PRIVATE WITH ANNUNCIATOR.

TS-2A (1/2

--

EOUIV.)

WATT TAP) SHOWN.

SEE TEXT FOR

Figure 1 - Connection Diagram,

TS-I6A

Speaker

TRANSFORMER

Installation

-3-

TO CONSOLE

SWITCH BANK

74-2588-A

Figure 2 - Room Speakers with Voice Call-In Switch, Connection Diagram

LINE

or for surface mounting in a standard deep single-gang
wire mold outlet box. Install the box in a location which
provides convenient access to both the switch and the
room speaker.

LINEMATCHING TRANSFORMERS

The installation diagrams show
transformers of
or TS-05). Other recommended transformers are shown
in figure 3. The console output is designed for a
constant voltage distribution system and all system
loudspeakers must be provided with line-matching
transformers.

¼

or %-watt capacity (Models TS-025

Bogen

line-matching

25-volt

CAUTION

Speakers and transformers must be proper­ly matched with respect to power

require-

men ts.

CONSOLETTE WIRING

Remove the Phillips-head screws securing the

louvered pane1 on the rear of the consolette (or console).

There are three rows of solder terminals across the rear

of each switchbank. Each selector switch corresponds
to the three terminals directly behind it, one terminal
from each row.

White tabs are provided for identifying the room con­trolled by each selector switch. Insert the tabs in the
slots provided in the transparent switch knobs. When
rooms are identified by number, it is common practice
to start numbering the switches from left to right (view­ing from the front or operator position), starting with

the top switchbank.

SWITCHBANK WIRING

Wire the switchbanks as shown in figure 4. If annun­ciator lamps are used (Model SBL), always solder the
single annunciator wire to the top solder terminal. For
all switch banks, solder the speaker lines to the center
and bottom terminals, with the shield to the ground bus
bar.

This is the only place where speaker shields should

be grounded.

VOICE CALL-IN OPTION

Figure 2 shows the room connections and switch re­quired for installing an optional voice call-in system.
The wiring must be completed by connecting the
shielded pair from the switch to the terminal strip on the

rear of the MCT-1 chassis. The polarity of the inner
conductors is not critical, but make certain to connect
the cable shield to the shield of the cable already con-

nected to the terminal strip.

Note that only one cable goes to the terminal strip.

Usually, the cables from all room switches are con-

nected by a common control cable and one cable is run
to the consolette. If this type of installation is not prac­tical, then the control cables for two or more switches
are run to the consolette. In this case, connect all the
cables in parallel in a junction box at the consolette and
run a single control cable from the junction box to the
terminal strip on the MCT-1 chassis.

CALL/PRIVACY OPTION

Figure lc shows the room connections and switch

quired for installing an optional annunciator/privacy

function in the intercom system.

re-

4-

CONTROL FUNCTIONS

All operating controls for the Series 15 Centralized
School Sound Systems are located on the front of the
consolettes (consoles). The Series
with an AM/FM radio tuner, while the Series 15-2 and

15-3 have both a tuner and an automatic record chang­er. The operating controls for the tuner and record
changer are described in their individual instruction
manuals.

MCT-1 CONTROL PANEL

The controls on the Model MCT-1 Control Panel are:
POWER ON-OFF SWITCH. Turns the system on and
off.
FUNCTION SELECTOR SWITCHES. These switches
determine the mode of system operation. These operat­ing modes are:

1.

Microphone. Connects microphone input to program

channel (selected by MIC level control).

2.

Program. Permits transmission of program material

as determined by program distribution and program
output switches.

3.

Intercom. Enables and disables TALK/LISTEN

switch.

4. Emergency. Permits operator to transmit to all sta­tions via panel speaker, regardless of switchbank set­tings. Overrides all program and intercom functions.
Operates with power switch On or Off.

5.

Talk/Listen. Allows operator to communicate with

room(s) selected on switchbank without affecting pro­gram distribution to remaining rooms. Enabled by In­tercom switch; depress to talk, release to listen.

15T-1

is equipped

CONSOLE SWITCH BANK

TYPE SBL SWITCH

SHIELDED PAIR

(BOGEN

BB-8450, OR EOUIV.)

NOTES

I-TERMINALS CORRESPOND TO SWITCH ON OPPOSITE

SIDE OF FRONT PANEL.

2-DRESS SPEAKER LEADS TO PREVENT SHORTING

LOWER TERMINALS TO GROUND BUS.

Figure 4 - Consolette Switch Bank, Connection

Diagram

LEVEL CONTROL SWITCHES

1.

Microphone. Fader control sets level of Mic 1 or Mic

2 program as indicated on output meter. May be used
with Program level control for mixing.

25

VOLTS

TS

RED

TS-2A

TS -

16A

OHMS

8

ONDARY

SEC

RED

BLK/YEL

YEL
YEL

-

8

OHMS

SECONDARY

l/8 W
l/4

w

l/2

w

I w

2

W

Figure 3 -Bogen Line-Matching Transformers

TS-

POWER

TAP

w

2

4

w

8 w

16

W

16A

CENTER

TAP

WHT

ORN

ORN

-5-