Rca Bc-3c User manual

.

BROADCAST

AND

COMMUNICATIONS

,

I ,

PRODUCTS

Type

·BC·3C

Siandard

Consolelle

MI-11641-A

(115

V)

M

1-11641-

B

(22

0

V)

~

,

~'.'

I'

;,

,-,.

--

1f"')

..

-.

"'I~

,-

. -

--

or

~

'F~

I·~

• . .,

-.-~

..

,,"

I-~'

~

--

• ,

..

',

•.

- _

--'-4

-.

--..

•.

,..

.....

• • -

---

:-

•-

~~

....!-

- • - -

---

-

11-24789-5

,

EQUIPMENT LOST OR DAMAGED

IN

TRANSIT

W hen deli

vering

the

equipment

10

you,

the

tru

k

dri\

'

cr

or

carrier's

agent

will

present

a receipt for your signa

ture

.

Do

nO

t siSn

it

until

you have

(a

)

inspeued

Ihe containers f

or

vi

s

ible

signs uf

damage

and

(b)

counted the

container

s and

compared

with

t

he

amount

shown

on

the

,hipping

papers.

If

a

shortage

or

if

evidence of

damage

is nuted, insist that

notation

to that effect be mndc on the 5hi

pping

papers

b~f

ore

yuu sign them.

Fu

rth

er, ufter receiving

th

e

equi

pment,

unpack

it aod insp"cI

thoroughly

for concealed damage.

If

concealed damage

is

discovered,

imme

di a

l

c

l~

'

no

tify (he

carrier,

confixming the notification in

writing,

and

se,ure

an inspection reporl.

This

item

should

be unpacked

and

in~pcctcd

f

or

damage

\;

'

ITH

IN

15

DAYS

after

receipt.

Report

all

shortages

and tlamages

{()

RCA, BroadClIst and

Tc

levi i

on

De

part

ment, amden 2, N. J.

Radio

Corpora

tion

of

America will

(j

le all claims for loss and

damage

on

this

equipment

so

long

as the inspection rcpo

Cl

i

obt

ained.

Disposition

of

(he damaged item will

be

furnishe

d

by

RCA.

REPLACEMENT PARTS

AND

ENGINEERING SERVICE

RCA field

engineering

service

is

available

at

current

rates. Requests

for

field

engineering

service may be addressed

to

your

RCA

Broadcast

Field

Representative

or

the RCA Service

Company,

Inc.,

Broadcast

Service Division,

Camden,

N.

J.

Telephone:

WOodlawn

3-8000.

W hen

ordering

repla

c

ement

parts,

ple

ase

give

symbol, des

criplion,

and

stock

number

of

each item

ordered.

The

par

t which

wi

ll

be

suppl

ied again

st

an

order

fur a

rep

lac

ement

item may not be an exact

duplicate

of

the

original

part.

Howe

ver, it will

be

a satisfactory re

pla

cement

diffed

ng

only

in

minor

mechanical

or

electrical

charaderistics.

Such

differ

ences

will

in no

way

imp

air Ihe op

erat

ion of the equipment.

Parts

with

no stock

numbers

are

standard

wmponenls

.

They

are nOI

slO

cked by RCA

and

sho

uld

be oblained from

your

local

electronic

parts

distributor.

The

following

tabulati

ons list service

part

s a

nd

ele

c

tr

on

tube

ordering

instructions

according

to

your

geographical

location.

SERVICE PARTS

LOCATION

ORDER

SERVtCE

PARTS

FROM:

Continental

United

States,

including

Alaska

RCA

Parts

and

An

'essories

Department,

P.O. Box 654, Camden,

and

Hawaii

New

Jersey

or

through

your

nearest

RCA Regional Office. Emergen"y

orders

may be telephoned,

telegraphed,

or

teletyped

to

RCA Emer·

gency Service, Bldg. 60,

Camden,

N.

J.

(Telephone:

WO

3·8000).

Dominion

of

Canada

RCA

Victor

Company

Limited, 1001

Lenoir

Street,

Montreal,

Quebec

or

through

your local Sales

Representative

or

his office.

Outside

of

Continental

United

States, Alaska, RCA

International

Division

,

Clark,

N.

].,

U.S.A.

or

through

your

local

Hawaii

and

the

Dominion

of

Canada

Sales Representative.

ELECTRON

TUBES

LOCATION

ORDER

ELECTRON

TUBES

FROM:

Continental

United

States,

and

Hawaii

including

Alaska Local RCA

Tube

Distributor.

Dominion

of

Canada

RCA ViclOr

Company

Limited, 1001

Lenoir

Street,

Montreal,

Quebec

or

through

your local Sales

Representative

or

his oflice.

Outside

of

Continental

United

States, Alaska, Local

RCA

Tube

DistribulOr

or

from:

Hawaii

and

the

Dominion

of

Canada

Tube

Department

RCA

International

Division

30

Rockefeller

Plaza

New

York

20,

New

York,

U.S.A.

RETURN

OF

ELECTRON

TUBES

If

for any reason,

it

is

desired

to

return

tubes, please

return

them

through

your local

RCA

tube

distributor,

RCA

Victor

Co.

Ltd.,

or

RCA

International

Div.,

depending

on

your

location

.

PletlJe do 1101 relurn lubes directly to

RCA

without

authorization and shipping ins/ructions.

It

is

important

that

complete

i

nformation

regarding

each

tube

(including

type, serial

number

,

hours

of service

and

reason

for its

return)

be given.

When

tubes are

returned,

they

should

be

shipped

to

the address spe(ified on the

Return

Authorization

forin. A copy

of

the

Return

Authorization

and

also

a Service

Report

for each tube

should

be packed

with

the t.ubes.

Allanla

3,

Georgia

1121

Rhodes·Haverty

Bldg.

134

Peachtree

St. N.W.

JAckson

4·7703

Chirago 54, III.

1186

Merchandise

Mart

Plaza

DElaware

7·0700

Hollywood

28. Cali/.

RCA Bldg., 1560 N.

Vine

St.

HOllywood

9·2154

BTE·6

Paterson, N.

/.

495

E.

30th

St.

MUlberry

4·0972

LIST

OF

RCA

SALES

OFFICES

Boston

16

, Mass.

Room 2301,

John

Hancock

Bldg.

200

Berkley

St.

HUbbard

2·5765

Cln

'eland 15,

Ohio

16()O

Keith

Bldg

.

CHerry

1·3450

Indianapolis, Ind.

501

N. LaSalle St.

MElrose

6·5321

Por/I,md

5,

Oregon

1208 S.W . 14th SI.

CApitol

6·6828

Ctlmaen 2,

N.

/.

Building

15

WOodlawn

3·8000

Da/lds

35,

Texas

7901

Empire

Freeway

FLeetwood

2·3911

Kansds City 15,

MiHouri

77

II

State Line Road

EMerson 1·(,770

5"'1

f'rtJll

circo 2, Calif.

420

Taylor

St.

OHdway

3·8027

Washing/on

6,

D.

C.

1725 K St., N.

W.

\

fEderal

7·8500

Char/olle 4. N.

C.

504

Charlottetown

Mall

3.B·39')6

De/roit 3'), Mich.

12605

Arnold

SI.

KEnwood

4·5100

New

York

20,

New

York

3(,

W.

49th

St.

)Udson

6·3800

Seallie.

Washing/on

22~O

first

Ave., S.

MAin

2·8350

I

BROADCAST

AUDIO

EQUIPMENT

INSTRUCTIONS

Type

BC-3C

Siandard

Consolelle

M

1-11641-

A (115

V)

MI-11641-B

(220

V)

In order to make improvements in design and effect econo-

mies in manufacture, RCA reserves the right to make changes

in design, components, and specifications published herein.

RADIO

CORPORATION

OF

AMERICA

BROADCAST

AND

COMMUNICATIONS

PRODUCTS

DIVISION

CAMDEN,

NEW

JERSEY

PRINTED

IN

U.S.A.

18-24789-5

\

1

2

Figure

I-Type

8C-3C

Standard

Consolelle

()

3

TECHNICAL

DATA

Power Required

155

watts

Inputs

6

microphones

(4

Studio,

1

Control

Room, 1 An-

nounce

Booth)

2

turntable

inputs

2

Remote

Lines

1

Network

1

Tape

1

Auxiliary

1

External

Monitor

Outputs

1

Program

Line

2

Monitor

Speakers

1

External

Monitor

2

Remote

Lines Cue

1

Turntable

Cue

Amplifiers

3

Preamplifier

2 Preamplifiers used as Boosters

Program

Amplifier

1

Monitor

Amplifier

Signal

to

Noise

Ratio

37

.5

/150/

6000pms

150

ohms

600

ohms

.600

ohms

150

ohms

150

ohms

600

ohms

600

ohms

18

dbm

16

ohms

3

Weach

600

ohms

-

6dbm

(,00

ohms

18

dbm

150

ohms

With

MIXER,

MASTER

and

MON

GAIN

controls

set

to

10

and

a-50

dbm

reference

signal

applied

to the

microphone

or

turntable

inputs,

or

16

dbm

applied

to

the

network

or

remote

line

inputs,

hum

and

noise

:

68

db

below

reference

at

program

line

output

66

db

below

reference

at

monitor

output

Gain

Microphone

to

Program

Line

Network

or

Remote

to

Program

Line

Turntable,

Tape

or

Auxiliary

to

Program

Line

Microphone

to

Speaker

(Audition)

Microphone

to

Speaker

(Program)

Microphone

to

External

Monitor

Microphone

to Remote Line

(Cue)

Network

to

Speaker

(Audition)

Network

to

Speaker

(Program)

Frequency Response

Program:

± 1.5

db

Monitor:

± 2.5

db

Harmonic Distortion

108

db

32

db

64

db

124

db

144

db

84

db

106

db

48

db

68

db

30

to

15,000 cps

30 to 15,000 cps

Program

18

dbm

output

1% 30 cps, .

75%

50 cps,

0.5%

100-15,000 cps

Monitor

6w

total

1.5%

50-10,000 cps

Tube

Complement

(MI-11486-Al

(Not

Supplied)

26V6GT

2 12AU7

2 12AX7

1

5R4GY

5 12AY7

5 MI-11299,

(selected

nAY7)

Dimensions

and

Weight

Width-33

inches

Height-ll

l

/4

inches

Depth-211

/4 inches

Weight-88

pounds

Finish:

two

tone

umber

gray

DESCRIPTION

The

BC-3C Standard Consolette is designed to

handle the programming schedules

of

a station

equipped with one

or

two studios, an announce booth,

a control room, two turntables, one tape recorder and

one auxiliary such

as

a film projector.

The

thirteen

inputs include six microphones, two turntables, one

tape, one network, two remote and one auxiliary.

The

network

and

remote lines may be monitored

by using the phone jack. Eight inputs may be simul-

taneously mixed. Separate audition

and

program

channels are provided and the monitoring amplifier

may be switched to the turntable cue position, pro-

gram line, audition line or external input.

The

BC-3C is completely self-contained, including

the amplifiers

and

power supply.

The

unit

is styled

for

convenience in operation, with the logical ar-

rangement

of

controls using col6red knobs and

for

convenience in servicing, with the hinged

front

panel

and

removable louvred top cover.

The

console housing

is

compact

and

designed to

match the styling

of

other RCA ,Audio consolettes

such

as

the BC-5B

or

the BC-6B. All these units are

designed to

be

mounted

on

a Bat desk

or

surface.

Another convenient feature is the script holder which

keeps the

program

where the operator may check it.

Associated

Equipment

The

necessary auxiliary units such

as

microphones,

loudspeakers, turntables, tape recorders

and

warning

lights, may be selected from the RCA catalogs. A

separate sheet

of

instructions is packed with each unit.

.-

...

-

.a-

C

..

•

I\,)

I

CD

0-

,.

~

tJ

Ii"

ca

..

Q

3

~

I

5

""

iDvu

10013

C.

R

c-----;:>I

~T\

.

f~~

!:!ILA.!if':l

"'

1('

l

~~I~--r-

-'

~

!l

5

p

PROOo."M

,

CL~

J

II

tt>

;.

""

,,

-

r"'"

"","C~~_"-,:'

''''~''

"~

.

,.,,-,_~~lb

--

-'

~l'

" ..

. ,

e,

v---'

'---""j_

,-

-n-

-

-,

.,.:

. I I - L - -

J

~n

LL-

_

--

-l

~

I

-.Q-+":O---.l

...

L

__

_

__

J "

,.....

!WOIl.~

.,,,'

~,

'"

~~

~"

~

--

~

:.

.

~

,san§11

~---

----

-"'

"

.,

...

0---.--"

- '

-,

~

"'

.

~

• .

5A

TI

!>

41

"'~

1\ •

~S7

~

c.UE

r

47

EX

'MON

INP

UT

n

~~4

",""Ii

~T

4

SAT4 , I

..

~

i

5Sb

~

A

!OS9

P

.-

--C

A

P

~

!OSII

~

A

P

!OlZ r

~L-...

19

1

50

n

AuX

A

OFr

RE"'21

~513

o

_~~

r

LINE

0..---

_

1

60

0Cl.

MON

AMP, RELAY':;

L~

~~.?J

5:>1

4

2.

600/\

5P!l1

~

I I

POWER

SUPPLY

NET

~

.

~.

,-.

ur.

v

~

PkONE >-

!>.I

I

08

1

100

-

I~OV

!IO/60'V

C>

,IIR7

""'N·

A'"

I"

D-637

B

77-2

51)

57

63

20013

15

1l. 6; C.R. 5PK'R

d 77

~

I

0 C R,

ON

A

IR

j

~

1

151l.

6

~

STUOIO

L

5PK

'R

o-.J

I

7'9

8 0 !ITO.

0"

A'R

.....

,

~~K2

-

~

In

regard

to

loudspeakers, however, a

few

points

should

be emphasized. Facilities are

provided

for

two

speakers. A

third

speaker may be

added

by

addition

of

accessory speaker relay

kit

MI-11748.

The

loud-

speaker

should

have a voice

CQil

impedance

of

15

ohms,

or

an impedance

matching

transformer

MI-

11731

must

be provided.

As to

warning

lights, the

MI

-11706 Series are

recommended

for

the

Studio

and

Control

Room.

The

lights

which are available

with

inscription, are listed

as

follows:

ON

AIR

REHEARSAL

AUDITION

STANDBY

SILENCE

MI-11706-1

MI-11706-2

MI-1l706-3

MI-1l706-4

MI-11706-5

An

MI-11702-A

Warning

Light

Relay is recom-

mended

for

each

warning

light

.

Circuit

Description

The

BC-3C Consolette amplifiers are constructed

on

individual

etched circuit boards.

External

connec-

tions

are

made

through

turret

type terminals

on

each

board.

The

boards are secured

with

standard

hard-

ware

to

a

metal

chassis

and

are easily loosened

or

removed

to

gain

access

to

the etched wiring.

Figure

3-Preamplifier

(SAR

J-SAR3J

Printed

Circuit

Soard

\

5

Preamplifiers

SAR1

to

SAR3

The

circuit

of

the

microphone

preamplifiers is

shown

in

the

schematic

diagram

of

figure

5.

The

input

signal is derived

from

an

unloaded

step-up

transformer

which

is

mounted

under

the preamplifier

mounting

shelf

and

is

applied

to

the

grid

of

the

input

stage.

This

stage is RC coupled

to

the

second

stage,

with

negative feedback

from

the

plate

of

the

second stage

applied

to

the

cathode

of

the

input

stage.

This

minimizes

distortion

at

high

input

levels. A

MI-1l299

tube

which is a 12AY7 selected

for

low

noise is used

in

this stage.

The

output

of

the second

stage is connected

through

the

coupling

capacitor

tC2

to

a

potentiometer

type

MIXER

gain

control

and

hence

to

the

grid

of

the

third

stage.

The

output

of

this stage is capacitively coupled

to

the

cathode

fol-

lower

output

stage. A 12AY7

tube

is used here.

To

eliminate any

doc

output

voltage

which

could

produce

switching clicks,

two

capacitors IC5

and

lC6

are

connected

in

series between

the

cathode

and

the

out-

put

terminal

with

shunt

resistors

lR12

and

IR13

bleeding

l\ny

charge

to

ground.

The

voltage

gain

of

the

amplifier is

approximately

46 db.

An

input

signal

to

the

transformer

primary

of

-50dbm

produces

an

output

signal

of

approximately

one volt.

Figure

4-Preamplifier

(SAR4,

SARSJ

Printed

Circuit

Soard

6

2

D IC21~

0

~.

'

~

__________

~

1

I'

Y21

2A

Y7

..I

I I

IVIA

I

~

I 1INPUT

1-1 : f 2

z 1 1

~m

3

,..--

....

i6-0UT

wle

;1

IoJ

lRl lR2

8200

lOOK

'w

-

~o

1R~

330K

5~o

lR6

B2K

lR7

16K

1W-

!!,.

IR8

220K

5..,0

IR13

220K

I

..

L~~

--

-A--~

--

~

--

~~~

__

4-

____

A-

____

~

__

~

______

-+

__

~~

__

-o6

le3

.02

2

27!JV

~

---------+----

~

----------

~

--------

--~--

--

~~-o

7

~

________

____

___

____

.-

____

~Z~8~!!_V~8

6·3V

8411457~

figure

5-Schemalic

Diagram

for Preamplifier

(SARJ-SAR3'

Booster Preamplifiers SAR4, SARS resistor

1Rl4

is added

to

roll off of the

high

fre-

quency response above

15

kc.

As shown

in

figure 6, this amplifier is similar to

the one shown above. Since

no

switching is per-

formed

in

the output,

the

second

output

capacitor

le6

and

shunt

resistor 1R13 are omitted. A series

2

lR1

8200

lW

-

~o

IRS

330K

5%

1R6

S2K

lR7

16K

1W-!!,.

Program Amplifier SAR6

The

program amplifier etched circuit board con-

tains all the electrical components except the

output

IR12

220K

le3

.022

L-

_________________

__

________

~---~Z~8~!J~V~8

641148<0-0

figure

6-Schemafic

Diagram

for Preamplifier (SAR4,

SARS'

,

transformer

5T7

which

is

mounted

on

the

chassis

directly

in

front

of

the

amplifier.

A 12AX7

twin

triode

is

used

for

the

input

and

phase

inverter

stage,

driving

two 12A

U7

twin

triodes

which

are

connected

in

push-pull

parallel.

Negative

feedback

is

derived

from

a

tertiary

winding

on

the

output

transformer.

An

input

voltage

of

approximately

1. 35

volts

is

re-

quired

to

obtain

an

output

of 30

dbm.

Monitor

Amplifier

5AR7

The

circuit

and

construction

ofthe

monitor

ampli-

fier

are

similar

to

the

program

amplifier.

The

output

transformer

5T8

is

mounted

directly

in

front

of

the

monitor

amplifier

printed

circuit

boards.

To

obtain

a

rated

output

level

of 6

watts,

a

pair

of

6V6GT

tubes

are

used

in

a

push-pull

output

stage.

Approximately

1.

32

volts

input

are

required

to

obtain

1

watt

output.

The

transformer

secondary

has

taps

for

600/150/16/8/4

ohm

loading.

Power

Supply

5PSl

The

powcr

supply

is

designed

for

operation

from

a

100-130

volt

50/60

cycl

e

or

a

205-240

volt

50/60

cycle

powcr

line.

Transformer

primary

taps

are

available

for

nominallinc

voltagcs

of

105/205,

115/

220

and

125/240

volts.

1'118

plate

supply

voltages

are

obtained

from

a 5R4GY

full-wave

rectifier

tube

and

filtered

by

several

stages

of

Re

networks

which

3R8

9

8

7

6

5

-'

_ _1

"""

4

3

3XV2

3RI2

3R4

2

2R2

2R7

2C3

2C5

2RI'

-+-

___

+-

t:~--

2R

I

2CI

~,.:o:~~....:t","".

2X

VI

2C2

2R6

c;f=:~""L

2R5

7

2R4

2R9

2XV2

2C4

2XV3

2RIO

Figure

7-ffrogram

Amplifier SAR6 Printed Circuit

Soard

3C 3

3C6

3XVI

3R7

3R2

3C

2

• •

~

-

3

CI

-""~

-'3R3

3R

I

tt3!

1---2

Figure

8-Monitor

Amplifier SAR7 Printed Circuit

Soard

r

8

C

12AX7

2CI

.047

2"

.047

2~7

120K

2R5

5%

2700

2'2

3~

"'

..

"

2R(;'

120K

~~

2CS

20

(JUT

r---

----

------~--

--------

----~6

2'12.

Go

12AU7

2V3

co

12AU7

2RII

10K

OUT

3

29SI/

9

,

2o-------~--

..

--------

..

--

..

------

..

--

..

------~--~------~~----------~

7

Fe

8

'p'

~~

7~

3060

-

0

Figure

9-Schematic

Program Amplifier 5AR6

OUT

c.

~--+-~------~~--~------~~--~----+-----~----------

--------

--~---4------~

4

3C7

20

3R12

6800

3RI3

22

K

Figure

lO-Schematic

Monitor Amplifier 5AR7

Z8SY 6

FEEDBAC.K

3

C-753Oe7-1

)

provide both isolation and sufficiently low ripple for

the various amplifier stages.

The

6.3v heater winding

connects through a hum adjustment potentiometer to

a positive bias voltage to minimize hum due to heater

to

cathode leakage. A full wave bridge type selenium

rectifier supplies d.c. power to the speaker relays. A

tap

is

provided on the transformer winding to com-

pensate for aging

of

the rectifier.

Fixed

Pod,

Etched wiring techniques are employed in the con-

struction

of

certain fixed attenuators, the same basic

board accommodates various circuit configurations

and resistance values.

The

line

input

pad

sA

TIl

is

a

balanced, center tapped H-type having a loss of

30

db.

The

line output pad

SA

T12 is a

balan~ed

H-type hav-

ing

a loss

of

6 db.

The

external

momtor

pad 5AT13

is

of

the balanced L-type having a loss

of

30

db.

9

Speaker Muting ond Warning Light Relays

5Kl

and 5K2

Relay SKI controls the control room speaker and

control room

ON

AIR light. Relay 5K2 controls

the

Studio speaker and Studio

ON

AIR light.

In

the de-

energized position, the speakers are on and the warn-

ing light circuit

is

open.

In

the energized position,

the speakers are off, a load resistance being connected

in their place and the warning light circuit

is

com-

pleted.

The

relays are controlled

by

the operation

of

the microphone selector switches

5S1,

S52, and

SS3

and the respective Program-Audition switches 5S5,

S56

and

5S7

.

The

relays

ar~

de-energized with

the

£witches

in

the

center (off) position and energized

in

the other positions.

To

energize SKI,

5S1

must be

in the CR

MIC

position. Refer to the chart, page

15.

115V A

(;

HUM

ADJ

4R9

Figure I

I-Power

Supply SPSI

,..

ca·

e

;;

-

~

L

'"

::r

ID

:I

Q

::".

'"

tJ

Q.

fa

a

:I

o

-

.,.

o

~

•

..

CIt

e

.,.

-<

«II

.,.

CIt

~

411

~

:

~

6

I

~

4 1 7

125/240V~

10

~

115/220V6-i

1_

~!>V

I~

I05/205V~

r--

2

<:

I

....

1\

I ,

co

,:

~!>V

2 1

9'

0 I

'--

Hal

I

1

I

1

I

12

I~

-

I

":l

I

I)

, 14

:~

I~

,~

~

W

~

~V-2A

4

2

1\

4R3

4'011 'ZOK

-- 6

!oR4

GY

,w

<4R4

~~i~

r-

'~

'OOV

4R9

i

100

2

HUll

AOJU~

rOC"'

-...

24V

N[W

26'01

A(lrtO

4RIA

100

4ru

O

lW

4"

'IRla

~

4R

Z

7!>0

A a

Co

40 40

40

tw

I

~OO

50'01

4R!>A

10

0 0 4R5B

4R5C

1000

100

0

1

A a ,

-r--

4C2

40

40 40

4RII

12

00

2W

4R5D

1000

4R7

10K

IIW

An

'1.

4'4

40

-

0-6432.64

4RI!

UK

IW

4R

IZ

1

0K

IW

4(,5

A B

40

I

4A1

-6800

-,w

4Rll

ZfwK J

~

AJ]

40

40...c

Z

~

C

r'<z

2

~

-

~

'"

-

7~V

BI

oov

B2

90."

1D

6!>V 1M

6~'"

U

~4C

40

,

90'"

86

265'01

aJ

290'01

a.

6

,

HI

6')V

~-4A

'"'

HZ

Rt

2.4'01.2,

RZ

....

o

----

,..

ca"

e

...

ill

-

~

o

::.

..

~

0"

::.

t:J

Q"

~

Q

3

o

-

.,.

o

~

..

...

CIt

e

'lJ

-<

'"

.,.

CIt

WIR

1~,(I.e.

II

IN

.0

.....

-

WH'T

-,

3 -. /

1.2

40

R£IYBlK.

7/0126

:'0

I

10

60

- 6.2

6L"CII

110

0

WN

•

00

6R1</1SLK•

110

ORANC.E

'20-

REI/SLUE

131-133

REDI

C.RN.

40

REOITfL

.

I~O

-'

SI

WHITE

-

YEI

/

~

RN

.

7/

10

170

I,

b

ISLEr

....

,N!>

81.11

• •

04

. 1·

0.

I'll)

~I

0 Ii

,::

-

:~::

*II

I I

'3?>-.CZ

-

~

«11

140

-

..

C2-

7

e:ll

I I 131"",,"- 6

4RS

:;

LEE

....

,

HO

-

4C!>

110-4R5-S

4(4

.rn

10

.

PARTSLI

iT

a90'

2~7"~02

If>.i

'.~~~

CT!;LI

NO

OPE./<

H&.

~-~7

_

8!.

~

-

~I

0:>-

!>z

~-

~3

&O~

-

6

!>4

!>,

60

&1

,

62

63

1105- 6

64

B 4 6

..

4 4

~'32·4R'-2

31-

4R.2-1

.r

NOTES

I'THE

fOLLOWINC.

WIR(5

...

RE

TWI:5TED

PAIR5

.

'20&"21

20

'30

90

&100

2-

SOLDER

ALL

(lECTRICAL

CONNECTION:'

U:'IN(,

ITEIoi

67

3 FlEND

TtRMINAL5

Of

4R~

TOWARD BOTTO

..

Of

C.HAS5IS.

~O

-4

R9-)

"T1

o

100

-

4R9

·

.--t--

....

JO-4XVI~

~-t

--

~

"O~TSI'

20-4XY'1'6

,-

T

4O-4TI-l-+I-

---..

_I \2:,

-4.Vt

b

80

-4CRI-2

62-4CI-4

I~O""CRI-3

120

-4XV1-

4t

1

1br---:l~l..K_t>I

..

C9-2

__

,

I

,;

-,,

\

~l-·

.

~

r.IJO

..

.

TI-

I"

.-

-

·~t

·

>.

:t

l.l'!>O

~T

I-I

!>

-

-r-

~8l~RtO"2

..

T6i'-1-

- 1

·3

1-4CI-5

~I

132

r:

F t

~,

4XVI

121'4T1-'~

120-411-7

~

<:7

<D

4

30-

4Tl'6

G)

2

0-

4T'-5

2'-

4RI-3

)(,,,'2>9-Q

....

12

Script Holder

As

shown in figure

1,

an aluminum bracket

is

mounted on the right

hand

side

of

the control panel.

This bracket

is

designed to hold the clip board which

is

used in broadcast stations

to

hold

the standard 8V2

x

II"

script sheets.

Overall System

As shown in the block diagram, figure 2, the BC-3C

Consolette provides eight mixing channels.

The

out-

put

of each mixing channel may be switched to either

a program

or

audition bus

by

means

of

the key

switches

5S5

through

5S12

.

The

program

bus con-

nects

through

a booster amplifier, master gain control,

progcam amplifier and 6db isolation

pad

to the pro-

gram line

output

terminals.

The

VU

meter and ex-

ternal monitor bridging pad are connected across the

output

of

the program amplifier.

The

monitor channel consists

of

a booster amplifier,

monitor gain control

and

monitor amplifier.

The

in-

put

selector switch gives the choice

of

monitoring the

output

of

the program amplifier, the

output

of

the

audition bus, an external

input

or

a turntable cue.

The

output of the monitor amplifier connects through

the speaker muting relays

to

the control room and

studio speaker

output

terminals. These relays also

actuate the ON AIR

warn

i

ng

light relays.

Cue feed to the remote line

is

supplied

by

the

monitor amplifier through an isolation pad. The two

remote line switches select headphone monitoring, cue

feed and program receive functions.

INSTALLATION

Location

of

ConsoleHe

The

BC-3C Consolette may be installed on any flat

top

desk

or

table

of

suitable size. A minimum

of

Vz

inch clearance should be allowed between the rear

of

the consolette

and

the

wall. Refer

to

the typical in-

stallation and dimensional drawings figures

15

and

16.

Removal

of

Shipping Bolts

Remove the red nuts and lockwashers located

at

each

end

of

the preamplifier shelf. Remove the ship-

ping

screw by pulling through holes on the underside

of the consolette housing. Removal

of

this shipping

hardware permits

the

preamplifier

mounting

shelf to

float freely

on

its rubber vibration mounts.

Type

of

Installation

A typical broadcast installation for a one studio

system using the BC-3C Consolette is shown

in

figure 17.

WARNING

Do

not

remove top cover

or

open front-

panel

with

power turned on unless thor-

oughly familiar with this equipment.

High

voltages appear on the etched wiring boards

and

terminal blocks. Caution must be exer-

cised when replacing tubes

or

servicing this

equipment with the power turned on.

Tube Installation

Tubes are

not

supplied

with

the consolette

and

must be ordered

as

MI-11486-A. Insert

the

tubes in

the sockets

as

called

for

on

figure 22. Install

the

selected 12AY7 (MI-11299) tubes in the socket near-

est the

front

of the preamplifier and booster amplifier

printed wiring boards. Slip the shields over the tubes

where tube shield

ground

straps are provided

on

the

Figure

14-Type

8C-3C Conso/elte with Panel

Open

)

13

CONSOLETTE

COfCQUrT

BOX

MAY

BE SET

IN WALL

OR

FLOOR

AS

SHO

~W=

N

===========~

..

~=:$

~

I>J

TH

REE

F

LEXleLE--iI>

~-

-to..;-'j

STEEL CONDU

ITS

d

,l

~

~ j

"'

.

,,

~

1<,

iI+---

CONOUIT

BOX

OPTIONAL

M

ET

HOD

~

j

OF INSTA

LL

ATION d

"'~

"

Cl

~

,

~

,.

~

'

/~

--

-

WA

L L

Figure J

5-Typical

Cable Inslallalion

sockets, making certain

that

the

ground

strap is

wedged between the tube envelope

and

the shield.

Power Supply 5PS1 Connections

The

consolette is shipped with the power trans-

former connected for power line voltage of 110 to

120 volts.

If

the line voltage is outside this range,

remove the four screws in each corner

of

the power

supply chassis.

Turn

the power supply upside down.

Remove the wire leading to terminal 3

of

the power

transformer

4Tl.

If

the line voltage is between 100

and

110 volts, connect this wire to terminal

2;

if

it

is between 120

and

130 volts, connect the wire to

terminal

4.

Replace the power supply. Connect the ac

power line to the barrier type terminal block 4TB

1

directly behind the power transformer.

For

conveni-

ence a power switch may be provided externally

to

turn the consolette on and

off.

External Connections

Audio wiring should

be

segregated into low level

(microphone and turntable inputs) and high level

(line input and

output)

cables

or

conduits.

low

level

audio lines should be shielded twisted pairs with

1--

- -

10

.

30

---

-i

~

-

...

~"'---

--------

---

:

~~

-----

---,

-~

Figure J

6-lnllallalion

Diagram

14

shields preferably insulated and grounded at one end

only. Low level audio wiring should be kept away

from AC

power

and signal

light

circuits. Connect a

ground

to the heavy bus wire adjacent to the audio

terminal block.

Microphone

and

Turntable

Connect microphone and turntable according to the

table

of

connections on 5TB

1.

All microphones in-

stalled in the same studio should be phased alike.

The

input

transformers

(5Tl,

5T2,

5T3)

are connected

for

a balanced 150-ohm input.

If

a 600-ohm

input

is

desired, reconnect by removing

jumper

between ter-

minals 1

and

3

and

4 and 6;

jumper

terminals 3 and

4. Remove

ground

connection from terminal 5 and

connect to terminal 4.

If

a 37.5

ohm

input

is desired, remove the jumpers

between terminals 1 and

3,

and 4 and 6

and

jumper

1

and

5,

and

2 and

6.

A center tap is

not

available

for

this impedance.

Remote Line

and

Network Inputs

A

600/600

ohm

pad

5ATll

having a loss

of

30

db

is inserted ahead

of

the

input

transformer 5T4. This

pad

may be modified or removed

if

so desired.

The

input

transformer

5T4 is connected

for

600-ohm in-

put.

If

desired

it

may be reconnected

for

150 ohms by

STO

MON

SPK

MIC

removing wire connected to terminal 1 and connect-

ing

it to terminal 2, and removing wire connected to

terminal 6 and connecting

it

to terminal 5.

Line Equalizer

An

Equalizer, such

as

the RCA BE-2A, MI-11752,

for

compensating the frequency response

of

the Re-

mote

and

Network

Lines may be connected to ter-

minals

25

and 26.

Program Line

The

program

output

line is connected

to

terminals

53

and

54.

A 6

db

isolation

pad

5AT12 having

the

impedance of 600 ohms

is

provided within

the

con-

solette.

Output

To External Monitor Amplifier

An

external monitor may be connected to a built-in

pad

5AT13 having an

output

impedance·

of

600 ohms

by

making connections to terminals

55

and 56.

External

Input

To

Monitor Amplifier

The

600-ohm impedance

output

of

an off-air tuner

may be connected

to

terminals

31

and

32

for off-air

monitoring

of

program.

MIC 2

STUDIO

MIC 3

MIC 4

ON

EXT

MON

LINE OUT

~:E~E:a~OTUTELE~~l-

_

-ft-

---i

?

~

i~

~

;

~

NET 0 0 0 0 0 0 0 0 0

TAPE I CONSOLE

BC-3C

AUXILIAR....

I

,

AIR I

!

r--------

8~'

, I

r-

__

1..

____

------1

I STUDIO CONTROL I 8T

<2

I

ROOM

I

• L .

_______

_

SOURCE

8-481432-2

Figure

17-Typical

Ins'al/ation for

One

S'udio

\

ANNOUNCE

BOOTH

;'

15

CONNECTIONS

AT

TERMINAL

BLOCK

5TBl

Loudspeaker Connections

Control Room Microphone 1 2 -

Th

I

- e contro room speaker

is

connected

to

terminals

Studio Microphone 1

3-4

Announce Booth Microphone

5-6

65

and 66 and the studio speaker to terminals 67 and

Studio Microphone 2

7-8

6S_

The

loudspeaker should have a voice coil im-

Studio Microphone 3 9-10 pedance

of

15-16 ohms.

For

other voice coil

im-

Studio Microphone 4

11-12

pedances, a matching transformer

is

suggested.

It

is

Turntable 1

13-14

• \ also possible

to

use speakers having a voice coil im-

Turntable 2 15-16

~

\ pedance

of

6-S

ohms

by

replacing the IS-ohm load

Tape 17-18 ·

f1,i;'f,

'f · 5R4 d R4 . h h .

A

'1

'

rAp

-

1920

11

'1

resIstors . 0 an 5 1

WIt

6-S

0 ms, 5 w resIstors.

UXI

lary C I.., - \

Remote Line 1

'/

L/I.~l

. 1

'~1-22

r-

Reconnect the wire leading to terminal 10

of

the

>

-L.olf.~rS

_I:.-,

. . .

Rmtote Line 2

~-

/C'

Tl'lff-

IIJ

~p

23-24

r-

momtor

output

transformer

5Ts

to termmal

9.

Line Equalizer

IN

25-26

NefWMk

~

i"

"-

~

27-28

_~

I

:'

Mounting

facilities are provided for two additional

speaker muting relays (accessory item MI-1174S).

Line Equalizer

our

29-30 '

External Monitor Input A I

e..

Program Mixing Bus

No

Connection

Program Booster Amplifier

Input

No

Connection

Audition Mixing Bus

'FartHaWe Cue

Output

L

f>l1..

1O

(,.C

J

Audition Monitor Input

Cue Monitor

Input

Not

used ', 77J CAlZ.r I

""~

f-

Not

used

(<:;(.

€

~P"t,)

n

)I"i,

7/.fE'

I"~

•

Program Line

External Monitor

Output

Monitor

Output

8 ohm

Monitor

Output

600 ohm

Not

used

Remote Line Cue Feed

Control Room Speaker

Studio Speaker

Control Circuit

Relay Supply

24

V

Not

used

Control Room

Warning

Light

Studio

Warning

Light

31-32

t-

33-34

35-36

37-38

Warning

Lights

39-40 Studio warning lights MI-11706 Series may

be

!1:!~

operated from the speaker muting relays.

It

is

ad.

4;.46

•

~

,

~le

to

use a MI·11702-A

Warning

Light Relay

47

-4

»'-'

]j

~/

,

with

each warning light.

The

Control Room signal

49·50

~

(~

'

light

circuit connects

to

terminals

77

and

7S,

the

51-52

-I-

~tudio

circuit to

79

and

SO.

53·54 -

I--

t.

55-56

57·58

59·60

61·62

63-64

65·66 H

67·68

69·70

71·72

73·74--}

75·76

77·78

I-

79·80

Hum

Adjustment

Before placing the consolette in operation, make

the following adjustment:

1. 5et the

input

selector switches 551

to

553 to

the

center

OFF

position. Make sure that the

other

inputs are terminated in a resistance.

2.

Set the mixer

output

switches 555

to

557 to

program position P.

RELAY,

SPEAKER

AND

WARNING

LIGHT

OPERATION

INPUT

MIXERS

LOUDSPKRS.

UGHT.'t

SPK.

RELAYS

SELECTORS 5S5

1S6

5S7

5S8

CR

STD

CR

STD

CR

STD

5S1

OFF

0

ON

OFF

OPEN

5S1

CR MIC P

OFF

ON

OFF

CLOSED

OPEN

5S1

MIC

1 P

ON

OFF OFF

ON

OPEN

CLOSED

5S2

ITI

P

ON

OFF OFF

OPEN

5S2

MIC

2 P

ON

OFF OFF

ON

OPEN

CLOSED

5S3

172

P

ON

OFF OFF

-

OPEN

5S3

MIC

3 P

ON

OFF OFF

ON

OPEN

CLOSED

554 REM P

ON

OFF OFF

OPEN

554

NET

P

ON

OFF

OPEN

5S1

CR

MIC

A

OFF

ON

OFF

CLOSED

OPEN

5S1

MIC

1 A

ON

OFF

ON

OPEN

CLOSED

5S2

IT1

A

ON

OFF

OPEN OPEN

5S2

MIC 2 A

ON

OFF

ON

OPEN

CLOSED

5S3

172

A

ON ON

OFF

OPEN

5S3

MIC

3 A

ON

OFF

ON

OPEN

CLOSED

554 REM A

ON ON

OFF

OPEN OPEN

554

NET

A

ON ON

OFF

OPEN

16

3.

Set mixers

5ATl

and 5AT3

and

master attenu-

ator 5A

T9

to maximum clockwise position.

Set mixers 5AT4 to

5ATs

to maximum coun-

terclockwise position.

4.

Adjust the hum control 4R9

on

the power

supply chassis

for

minimum hum

in

the

output

to the program line.

Control Circuit Modification

If

the Announce Booth microphone

input

is

to be

used

as

a studio microphone, jumper terminals 70,

71

and

72

on

terminal block 5TB!.

VU Meter AHenuator

The

VU

meter attenuator is designed

to

give a

meter reading

of

0

on

the

VU

scale with

an

output

of

S dbm delivered to a 600-ohm load connected to

the program

output

terminals.

If

it

is desired to have

the meter read 0

at

another output level, replace

resistors 5R3l, 5R32, and 5R33 with the values con-

tained in the table shown below:

Output

Level

SR31

SR32

SR.13

(DBM)

ohms ohms ohms

-2

3600 0

omit

0 4047 447 16790

2 4482 883 8180

4 4896 1296 5220

6 5279 1679 3690

8 5626 2026 2741

10

5934 2334

2091

12 6203 2603

1621

14

6433 2833

1268

OPERATION

The

front

panel, figure IS, and the chart Control

Functions supply complete identification and function

of

all controls

and

switches on the control panel.

It

ANB

aMIC2

MIX 2

REM-NET

MIX

4

is advisable to be familiar with this information for

thorough

understanding

of

the flexibility

of

the

equipment.

TT2

AUX

Figure J

8-Cont,o'

Pane'

\

)

17

CONTROL

FUNCTIONS

Panel Knob

Designation Symbol Color Function Coordinated

with

INPUT

SELECTOR

SWITCHES

CR MIC 551 Black 5e1ects control room

or

studio microphone 1 5AT1, 555

MIC 1

AN

B 552 Black 5elects announce booth or studio microphone 2

5An,

556

MIC

2

MIC

3 553 Black Selects MIC 3

or

MIC 4 in studio 5AT3, 557

MIC 4

REM

5S4

Red Selects remote program

thru

REM

1,

REM 2 5AT4,

5S8

NET

Selects network program 5513, 5S14

MIXER

ATTENUATORS

Controls gain

of:

MIX

1

5ATl

Black CR MIC

or

MIC

1 551, 555

MIX

2 5AT2 Black MIC 2

or

AN

B MIC

5S2,

556

MIX

3 5AT3 Black MIC 3

or

MIC 4

5S3,

557

MIX

4 5AT4 Red REM

or

NET

lines

In

maximum counterclock- 554, 558

TT

1 5AT5 Blue

TT

1 wise position

output

of

559

TT

2 5AT6 Blue

TT

2 mixers is connected to CUE 5510

TAPE 5AT7 Black TAPE position of monitor input

5S11

AUX

5AT8 Green Auxiliary Input selector switch

5S

15

5512

MIXER

SWITCHES

A-P

~55

Black

When

in position P, connects the mixer control to the 551,

5ATI

A-P

556 Black program channel 552,

5An

A-P

5S7

Black

5S3,

5AT3

A-P

5S8 Red 554, 5AT4

A-P

5S9

Blue 5AT5

A-P

5510 Blue

When

in position A, connects the mixer control to the 5AT6

A-P

5S11

Black audition channel

5An

A-P

5S12

Green 5AT8

REMOTE

LINE

SELECTOR

SWITCHES

REM 1

5S13

Black Selects remote line

#1

for headphone, cue and pro- 554, 5S8

gram 5AT4

REM 2 5514 Black Selects remote line

#2

for headphone, cue and pro- 5J2

gram

MASTER

GAl

N

CONTROL

MASTER 5AT9 Black Controls gain of program channel

MONITOR

INPUT

SELECTOR

SWITCH

MON

INPUT

5515 Black Selects input of monitor amplifier, position

OFF-EXT

5ATlO

-CUE-PGM-AUD

MONITOR

GAIN

CONTROL

MON

GAIN

5ATlO Black Adjusts level required for speakers, positions 0-20

5S15

PHONE

SELECTOR

SWITCH

PHONE

5516 Black Selects source for headphones; has 4 positions

OFF-

5J1

REM-NET-PGM

,

I

1

IS

Routine Procedure

1. Select the input desired.

2.

Move corresponding A-P mixer switch to the

desired function, Audition

or

Program.

3.

Turn

corresponding mixer attenuator up.

4.

Turn

MASTER control to level desired. (Ad-

just MASTER and MIXER controls to approximately

the same setting.)

5.

Check level

on

the

VU

meter; the meter pointer

should

not

swing over the red line on the

VU

scale.

6.

Monitor the selected input by turning

MON

INPUT

to selected function.

The

NET

and

REM

inputs and the

PGM

output may

be

monitored

through headphones plugged into the

PHONE

jack

5

Jl

with the

PHONE

selector switch

58

16

turned to

the selected function.

7.

Program may be monitored from an off-air

tuner

by

turning the

MON

INPUT

switch

5S15

to

EXT

.

With

the

MON

GAIN

control 5ATtO adjust

the volume

of

the loudspeakers

as

required.

To put a local program on the air

1. Select

the

microphone inputs desired on 5S1,

5S2,5S3.

2.

Move corresponding Mixer Switches

as

required

to P position.

3.

Turn

MON

INPUT

switch 5515

to

PGM.

4.

Turn

up

MIX

1,

MIX

2,

MIX

3,

as

required,

and

adjust

to

obtain desired balance

of

output

from

the microphones.

5.

Adjust MASTER gain control 5AT9

to

the de-

sued

level on the

VU

meter.

6.

The

program may

be

monitored over head-

phones

or

both

loudspeakers except

that

the Control

Room speaker

is

muted when the CR microphone is

in

use

and

the

Studio Speaker is muted when a studio

microphone is in use.

With

the

MON

GAIN

control

5ATI0, adjust the volume

of

the loudspeakers

as

re-

quired.

To audition a program

1.

Select

the

inputs desired 551, 5S2,

5S3

or

all

three.

2.

Move corresponding mixer switches

to

A.

3.

Tum

up

corresponding

MIX

1,

2,

3.

4.

Set the

Monitor

Input

Selector with

5S15

to

AUD.

5.

The

audition may

be

heard

as

when monitoring

a program.

To put network program

on

the air

1.

Move the key switch 554 to NET.

2.

Move Mixer Switch

5SS

to P.

3.

Turn

MON

INPUT

switch

5S15

to PGM.

4.

Turn

up

MIX

4.

5.

Adjust MASTER gain control

to

desired level.

6.

Network program may be heard over both loud-

speakers.

With

the

MON

GAIN

control adjust the

volume

of

the loudspeakers

as

required.

To audition a network program

1.

Move key switch 554 to NET.

2.

Move mixer switch

5SS

to

A.

3.

Turn

MON

INPUT

switch

5S15

to AUD.

4.

Tum

up

MIX

4.

5.

Network audition may be heard over both loud-

speakers.

With

MON

GAIN

control, adjust the

volume

of

the loudspeakers

as

required.

To monitor a network program

Plug

the headphones into the

PHONE

jack

to

monitor the program

as

received from the network,

with the

PHONE

selector switch in

NET

position.

To put a remote program on the air

1. Switch REM

1,

5S13

(or

REM 2, 5S14) is nor-

mally

at

CUE position before remote operation.

Then

tum

switch corresponding

to

the desired line to

PGM

to

put

program

on

the air.

2.

Move the key switch 554 to REM position.

3.

Move the corresponding mixer switch

5SS

to

P.

4.

Turn

MIX

4

up

and adjust MASTER gain con-

trol to desired level.

5.

Tum

MON

INPUT

switch

5S15

to PGM.

6.

With

the

MON

GAIN

control, adjust the

volume

of

the loudspeakers

as

required.

To audition a remote program

1. Select a remote program according to the above

procedure except the mixer

SWItch

5S8

is moved

to

A

or

the audition position.

2.

Tum

the

MON

INPUT

switch 5515 to AUD.

3.

With

the

MON

GAIN

control, adjust the vol-

ume

of

the loudspeakers

as

required.

Turntable, Tape and Auxiliary Inputs

These inputs are used

for

programming and audi-

tioning in exactly the same manner

as

the microphone

and

network-remote inputs except that no

input

se-

lector switch

is

used.

To

cue set the

MON

INPUT

RCA BC-3C User manual

Popular Music Mixer manuals by other brands