Harris BC-1G User manual

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)
T.M. No. 888-0800-002
© Copyright Harris Corporation
1982
All rights reserved
994 6245 001
994 6245 003
TECHNICAL MANUAL
BC-lG
1000/250WATT
BROADCASTTRANSMITTER
888-0800-002
Reprinted : July 1982
I

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Returns And Exchanges
Damaged
or
undamaged equipment should
not
be returned unless written approval
and a Return Authorization is received from HARRIS CORPORATION, Broadcast
Systems
Division. Special shipping instructions and coding will be provided
to
as-
sure
proper
handling. Complete details regarding circumstances and reasons for
return are
to
be included in the request for return. Custom equipment or special
order
equipment
is
not
returnable. In those instances where return
or
exchange
of
equipment
is at the request
of
the customer, or convenience of the
customer
, a
restocking
fee
will be charged. All returns will be
sent
freight prepaid and properly
insured by
the
customer. When communicating with HARRIS CORPORATION,
Broadcast
Systems Division, specify the HARRIS Order Number or Invoice
Number. Unpacking
Carefully
unpack
the equipment and preform a visual inspection
to
determine that
no
apparent
damage was incurred during shipment. Retain
the
shipping materials
until it has
been
determined that all received equipment is
not
damaged. Locate
and retain all PACKING CHECK LISTs. Use the PACKING
CHECK
LIST
to
help
locate and identify
any
components
or
assemblies which are removed
for
shipp
ing
and
must
be reinstalled. Also remove
any
shipping supports, straps, and packing
materials
prior
to
initial turn on.
Technical Assistance
HARRIS
Technical and Troubleshooting assistance is available from HARRIS Field ,-
Service during normal business hours (8:00
AM
-5:00
PM
Central Time). Emer-
gency
service
is available
24
hours a day. Telephone
217
/222-8200 to
contact
the
Field Service Department or address
cor
respondence to Field Service Department,
HARRIS
CORPORATION, Broadcast Systems Division, P.O.
Box
4290, Quincy, Illi-
nois 62305-4290, USA. The HARRIS factory may also
be
contacted through a FAX
facility
(217/221
-7096)
. Replaceable Parts Service
Replacement
parts are available
24
hou.rs a day, seven days a
week
from
the
HARRIS
Service Parts Department. Telephone [phone] to contact the service
parts
department
or address correspondence to Service Parts Department, HAR-
RIS
CORPORATION, Broadcast Systems Division, P.O. Box
4290
,
Quincy, Illinois
62305-4290
,
USA.
The
HARRIS factory may also
be
contacted through a
FAX
fa-
cility (217/221-7096). .
NOTE
Th
e#
symbol used in the parts list means used with (e.g.
#COO
l = used with CO
O!
).
_J_

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)
Guide to Using Harris Parts List Information
Toe Harris Replaceable Parts List Index portrays a tree structure with the major items being leftmost in the index.
The example below shows the Transmitter as the highest item in the tree structure. If you were to look at the bill of
materials table for the Transmitter you would find the Control Cabinet, the PA Cabinet, and the Output Cabinet. In
the Replaceable Parts List Index the Control Cabinet, PA Cabinet, and Output Cabinet show up one indentationlevel
below the Transmitter and implies
that they are used in the Transmitter. Toe Controller Board is indented one level
below the Control Cabinet so it will show up in the bill of material for the Control Cabinet Toe tree structure of this
same index
is shown to the right of the table and shows indentationlevel vers us tree structure level.
Example
of Replaceable Parts List Index and equivalent tree structure:
Tobie 7-1.
Table 7-2.
Tobie 7-3.
Tobie 7-4.
Tobie 7-5.
Table 7-6.
Tobie 7-7.
Reoloceable Parts List Index
Transmitte r 994 9283 001
Control Cabinet 992 9244 002
Controller Board 992 8344 002
PA Cabinet 992 9400 002
PA Amplifier 994 7894 002
PA Amplifier Board 992 7904 002
Output Cabinet 992 9450 001
I
Transmitter I
994 9283 001
7-2 __ __c--=--=--=---=:~--::=====:±====:;-1----;::,..::::.-=-=-=i~--
7_3 I Contro l Cabinet I I PA Cabinet I Output Cabinet I
7-6 992 9244 002 992 9400 002 992 9450 001
7-7 ⇒ I I
7-9 [Controller Board I I PA Amplifier I
7-10 992 8344 002 994 7894 0021
7-12
I
PA Amplifier Boord!
992 1904 002 I
Toe part number of the item is shown to the right of the description as is the page in the manual where the bill for
that part number starts. .
Inside the actual tables, four
main headings are used:
Table #-#. ITEM NAME -HARRIS PART NUMBER -this line gives the information that corresponds to the
Replaceable Parts List Index entry;
HARRIS PIN
column gives the ten digit Harris partnumber (usually in ascending order);
DESCRIPTION column gives a
25 character or less description of the part number;
REF. SYMBOLS/EXPLANATIONS column 1) gives the reference designators for the item (i.e., COOl. R102,
etc.) that corresponds to the number found in the schematics (COOl in a bill of material is equivalent to Cl on the
schematic)
or 2) gives added information or further explanation (i.e., "Used for 208V operation only," or "Used
for HT lOLS only," etc.).
Inside
the individual tables some standardconventions are used:
A# symbol in front of a component such as #COOl under the REF. SY},,fBOLS/EXPLANATIONS column means
that this item is used on or with COOI and is not the actual part number for COOL
In the ten digit part numbers, if the last three numbers are 000, the item is a part that Harris has purchased and
has not manufactured or modified. If the lastthree numbers are other than 000, the item is either manufactured by
Harris or is purchased from a vendor and modified for use in the Harris product.
The first thr ee digits of the ten digit part number tell which family the part number belongs to -for example, all
electrolytic (can) capacitors will
be in the same family (5.2A xxxx COO). If an electrolytic (can) capacitor is found
to have a 9xx xxxx xxx part number (a number outside of the normal family of numbers), it n as probably bem
modified in some manner at the Harris factory and will therefore show up farther down into the individual pans
list (because each table is normally sorted in ascending order). Most Harris made or modified assemblies will
have 9xx xxxx xxx numbers associated withthem.
Toe term "SEE HIGHER LEVEL BILL" in the description column imp lies that the reference designated part
number will show up in a bill that is higher in the tree structure. Titis is often the case for components that may
be frequency determinant or voltage determinant and are called out in a higher level bill structure that is more
customer dependent than the bill
at a lower le vel.
2-02-93

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';JARR'SBroodcost
Systems
o;v;s;on I I
HARRIS PHONE:
217-222-8200
P
.o.
·
Box
4290,
QUINCY, IL
62305
PARTS
ORDER
FORM
HARRIS FAX:
217-221-
7096
I
BILLING INFORMATION I I
SHIPPING INFORMATION I
CUSTOMER
NAME:
ADDRESS:
TELEPHONE NUMBER:
FAX NUMBER:
PREFERRED
PAYMENT METHOD:
FREQUENCY
(If
required):
EQUIPMENT NAME:
EQUIPMENT PART NUMBER:
EQUIPMENT SERIAL NUMBER:
ITE>.A
II
QTY
ORD
{
\
HARRIS
PART
NUMBER
i-
DESCRIPTION
OF
PART
(PART'S
NAME,
DESCRIPTION,
SPECIFICATION
FROM
PARTS
LIST
IF
AVAILABLE)
SHIP
TO:
(if
different
from
billi
ng
information)
ADDRESS:
TELEPHONE
NUMBER:
FAX NUMBER:
SHIPPING
METHOD
PREFERRED:
GUIDE
FOR
ORDERING
PARTS
Please use the following
ports
order
form,
filling
is
as
much
informa
tio
n
as
possible. The
complete
informolton
wn1
allow double checking the
port
number
for
correctness or
locating
a subslitude
lf
the
port
is
not
available,
The equipment name,
port
number, and serial
number
will
be
found
on
the
metal
ID
plate
on the
bock
of
the
unit
.
The
serial
number
MUST
be
Included
for
a
ny
ports
ordered
under
warranty.
Describe
the
port
usi
ng
the
description
!n
the
ports
list
if
possible. Include
the
schematic
information,
schematic number,
or
number
of
next
higher assembly. The
next
higher
assembly
is
usually o
992-xxxx-OOx
type.
ITEM
USED
ON
SCHEMA
TIC
REFERENCE
(NEXT
HIGHER
ASSEMBLY
Ir
KNOWN)
REFERENCE
NAME
(e.g.
COOi
used on 992
8025
001,
COMMENTS
(e
.g. C001, R100,
etc)
SCHEMA
TIC
839
8099
991)
\.
...,,,
- I
__)
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)
WARNING
THE CURRENTS AND VOLTAGES IN THIS EQUIPMENT ARE
DANGEROUS. PERSONNEL MUST AT ALL TIMES OBSERVE
SAFETY REGULATIONS.
This manual is intended as a general guide for trained and qualified personnel
who are aware of the dangers inherent in handling potentially hazardous
electrical/electronic circuits. It is not intended to contain a complete
statement of all safety precautions which should be observed by personnel in
using this or other electronic equipment.
The installation, operation, maintenance and service of this equipment
involves risks both to personnel and equipment, and must be performed only by
qualified personnel exercising due care. HARRIS CORPORATION shall not be
responsible for injury or damage resulting from improper procedures or from
the use of improperly trained or inexperienced personnel performing such tasks ·.
During installation and operation of this equipment, local building codes and
fire protection standards must be observed. The following National Fire
Protection Association (NFPA) standards are recommended as references:
Automatic Fire Detectors, No. 72E
Installation, Maintenance, and Use of Portable Fire Extinguishers,
No. 10
Halogenated Fire Extinguishing Agent Systems, No. 12A
WARNING
ALWAYS DISCONNECT POWER BEFORE OPENING COVERS,
DOORS, ENCLOSURES, GATES, PANELS OR SHIELDS.
ALWAYS USE GROUNDING STICKS AND SHORT OUT HIGH
VOLTAGE POINTS BEFORE SERVICING . NEVER MAKE
INTERNAL ADJUSTMENTS, PERFORM MAINTENANCE OR
SERVICE WHEN ALONE OR WHEN FATIGUED.
Do not remove, short-circuit or tamper with interlock switches on access
covers, doors, enclosures, gates, panels or shields . Keep away from live
circuits, know your equipment and don't take chances.
WARNING
IN CASE OF EMERGENCY ENSURE THAT POWER HAS BEEN
DISCONNECTED.
WARNING
IF OIL FI LLED OR ELECTROLYTIC CAPACITORS ARE UTILIZED IN
YOUR EQUIPMENT, AND IF A LEAK OR BULGE IS APPARENT ON THE
CAPACITOR CASE WHEN THE UNIT IS OPENED FOR SERVICE OR
MAINTENANCE, ALLOW THE UNIT TO COOL DO\m BEFORE ATTEMPTING
TO REMOVE THE DEFECTIVE CAPACITOR. DO NOT ATTEMPT TO
SERVICE A DEFECTIVE CAPACITOR WHILE IT IS HOT DUE TO THE
POSSIBILITY OF A CASE RUPTURE AND SUBSEQUENT INJURY. I .

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TREATMENT
OF
ELECTRICAL
SHOCK
1.
IF VICTIM IS
NOT
RESPONSIVE
FOLLOW
THE
A-B-CS
OF
BASIC LIFE
SUPPORT.
PLACE
VICTIM FLAT
ON
HIS
BACK
ON
A
HARD
SURFACE
®
AIRWAY
IF
UNCONSCIOUS.
OPEN
AIRWAY
LIFT
UP
NECK
PUSH
FOREHEAD
BACK
@ BREATHING
IF
NOT
BREATHING.
BEGIN ARTIFICIAL BREATHING
TILT
HEAD
CLEAR
OUT
MOUTH
IF
NECESSARY
OBSERVE
FOR
BREATHING
PI
NCH
NOS
TR
I
LS
MAKE
AIRTIGHT
SEAL
4 QUICK FULL
BREATHS
CHECK
CAROTID
PULSE
REMEMBER
MOUTH
TO
MOUTH
RESUSCITATION
MUST
BE
COMMENCED
AS
SOON
AS
POSSIBLE
IF
PULSE
ABSENT.
BEGIN ARTIFICIAL
CIRCULATION
© CIRCULATION
DEPRESS
STERNUM
11/2
TO
2
INCHES
APPROX.
RATE
{ONE
RESCUER
OF
COMPRESSIONS
15
COMPRESSIONS
--80
PER
MINUTE
2
QUICK
BREATHS
APPROX.
RATE
{TWO
RESCUERS
OF
COMPRESSIONS
5
COMPRESSIONS
~~-~~
--60
PER
MINUTE
1
BREATH
NOTE:
DO
NOT
INTERRUPT
RHYTHM
OF
COMPRESSIONS
WHEN
SECOND
PERSON
IS GIVING
BREATH
CALL
FOR
MEDICAL ASSISTANCE
AS
SOON
AS
POSSIBLE.
2. IF VICTIM IS RESPONSIVE.
A.
KEEP
THEM
WARM
B.
KEEP
THEM
AS
QUIET
AS
POSSIBLE
C.
LOOSEN
THEIR CLOTHING
D.
A RECLINING POSITION IS
RECOMMENDED

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)
FIRST-AID
Personnel
engaged
in
the
installation,
operation,
maintenance
or
servicing
of
this
equipment
are
urged
to
become
familiar
with
first-aid
theory
and
practices.
The
following
information
is
not
intended
to
be
complete
first-aid
procedures,
it
is
brief
and
is
only
to
be
used
as
a
reference.
It
is
the
duty
of
all
personnel
using
the
equipment
to
be
prepared
to
give
adequate
Fmergency
First
Aid
and
thereby
prevent
avoidable
loss
of
life.
Treatment
of
Electrical
Burns
1.
Extensive
burned
and
broken
skin
a.
Cover
area
with
clean
sheet
or
cloth.
article.)
(Cleanest
available
cloth
b.
Do
not
break
blisters,
remove
tissue,
remove
adhered
particles
of
clothing,
or
apply
any
salve
or
ointment.
c.
Treat
victim
for
shock
as
required.
d.
Arrange
transportation
to
a
hospital
as
quickly
as
possible.
e.
If
arms
or
legs
are
affected
keep
them
elevated.
NOTE
If
medical
help
will
not
be
available
within
an
hour
and
the
victim
is
conscious
and
not
vomiting,
give
him a weak
solution
of
salt
and
soda:
1
level
teaspoonful
of
salt
and
1/2
level
teaspoonful
of
baking
soda
to
each
quart
of
water
(neither
hot
or
cold).
Al
low
victim
to
sip
slowly
about
4
ounces
(a
half
of
glass)
over
a
period
of
15
minutes.
'
Discontinue
fluid
if
vomiting
occurs.
(Do
not
give
alcohol.)
2.
Less
severe
burns
(1st
&
2nd
degree)
a.
Apply
cool
(not
ice
cold)
compresses
using
the
cleanest
available
cloth
article.
b.
Do
not
break
blisters,
remove
tissue,
remove
adhered
particles
of
clothing,
or
apply
sal~e
or
ointment.
c.
Apply
clean
dry
dressing
if
necessary.
d.
Treat
victim
for
shock
as
required.
e.
Arrange
transportation
to
a
hospital
as
quickly
as
possible.
f.
If
arms
or
legs
are
affected
keep
them
elevated.
REFER.ENCE:
ILLINOIS
HEART
ASSOCIATION
AMERICAN
RED
CROSS
STANDARD
FIRST
AID
AND
PERSONAL
SAFETY
MANUAL
(SECOND
EDITION)
888-0800-002
iii

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TABLE
OF
CONTENTS
Paragraph
1-1.
1-3.
1-4.
1-12.
1-14.
1~19.
1-20.
1-24.
1-26.
1-28.
1-30.
2-1.
2-3.
2-4.
2-5.
2-9.
2-ll.
2-12.
2-13.
2-14.
2-
15.
2-16.
2-17.
2-18.
2-19.
2-20.
2-26.
2-27.
2-28.
2-29.
2-30.
2-32.
2-33.
2-34.
2-35.
2-36.
2-3
7.
2-39.
2-40.
2-41.
iv
SECTION
I.
GENERAL
DESCRIPTION
Introduction
..................................................
Mechanical
Construction••••••••··••··•
•
••··•··••••••••·••·••••
BC-1
G
Tr
ans
mitt
er
••.•.•.•••••.••..•.•
•
.•.••••....••......
•
..
M5422
Oscillator
Unit
.......................................
Transmitter
Controls
..........................................
Incidental
Information•••••••••••·•
-
••···••········•···••••••••
Tube
Handling
...............................................
Transmitter
Building
Temperatures
...........................
Grounding
.•••.•
~
••••••.•••••
.
.••••.••.••.••••••..•••.•••.••••
............................................
Antenna
Coupling
Technical
Characteristics
.....................................
SECTION
II.
INSTALLATION
General
.......................................................
Installation•••••••••••••·••·••·•·•·•···•••••••••••••••••·••••
Installation
Hints
..........................................
Transmitter
Inspection•••••••••••••••••·••••••••••••••••·•••
Transmitter
Connections•••••••••••••·•••••••••••·•••••••••••
Primary
Power
••.•.•.•.•.•••..•.••.••.••••••••.••••••••..•.
Transmitter
Ground··········•·•·•••••·••••••••••••••••·•••
...............................................
Audio
Input
?-t>dulation
Monitor
.
.......................................
Frequency
Monitor
RF
Output
.................................................
Remote
Control
(If
Used)
Detailed
Instructions
for
Remote
Control
Connections
Plate
Rheostat
Motor
Assanbly
•••••••••••••••••••••••••••
RelDC>te
Power
Change
.••••••••••••••••••••••••••••••••••••
Reset,
Plate
Off
(Setting
Up
Auxiliary
Relay
K9)
••••••••
Rem:>te
Plate
Voltage
Indication••••·••••••·••·••··•••••·
Remote
Plate
Current
Indication·•••·••·••··••·••····••·•
Renx>te Tower
Light
Indication•••••••••••••••••••••••••••
Remote
Antenna
Current
Metering•••••••••••••••••••••••••
Studio
Procedure,
for
Remote
Control
Operation
••••••••••••
Placing
the
BC-lG
On
the
Air
With
1000
Watt
Carrier
•••••
Placing
the
BC-lG
On
The
Air
With
250
Watt
Carri~r
••••••
With
Transmitter
Operating
At
1000
Watts,
To
Drop Power
To
250
Watts
............................................
With
Transmitter
Operating
At
250
Watts,
To
Raise
Power
•..••.••••.•••••••••••.••.•••.••.••••.•...
To
Raise
Or
Lower
Transmitter
Power
By
Means
of
Plate
Rheostat········•······••·•·••··•·•••·
Transmitter
Operating,
Having
Power
Failure
At
The
Studio
•..•••••••••.•••••••.....•.•........•.••.•.
Transmitter
Operating,
To
Shut
Down
At End
of
the
Day
•••
Crystal
Installation
....••....••..•.........•...............
888-0800-002
WARNING:
Disconnect
primary
power
prior
to
servicing.
1-1
1-1
1-1
1-2
1-2
1-3
1-3
1-4
1-4
1-4
1-4
2-1
2-1
2-1
2-1
2-2
2-2
2-2
2-2
2-2
2-2
2-2
2-3
2-3
2-3
2-3
2-5
2-5
2-5
2-6
2-6
2-7
2-7
2-7
2-7
2-8
2-8
2-8
2-8
2-9
I-
)
.,/
-

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-,
)
-
:)
TABLE
OF
CONTENTS
(Continued)
Paragraph
3-1.
3-3.
3-4.
3-6.
3-10.
3-11.
3-16.
3-30.
3-33.
3-35.
3-36.
3-3
7.
3-40.
4-1.
4-3.
4-10.
4-14.
4-17.
4-21.
4-23.
4-34.
4-38.
4-40.
4-44.
4-48.
5-1.
5-3.
5-10.
5-13.
5-15.
5-17.
5-19.
5-21.
6-1.
-
7-1.
SECTION
III.
THEORY
OF
OPERATION
Introduction
..................................................
Theory
•••••.••.•.•.•..•.••.•••••••.••••...•••.•.•.•..•.•.••••.
M5422
Oscillator
Unfr,
Simplified
Theory
••••••••••••••••••••
M5422
Oscillator
Unit,
Detailed
Theory·•••••••··••··••••••••
12BY7A
First
IPA
•••.•••••••••••.••
·•
•....•••.••.•.•••••••••
BC-lG
Transmitter,
Simplified
Theory
••••••••••••••••••••••••
BC-lG
Transmitter,
Detailed
Theory••••••••••••••••••••••••••
Power
Supplies,
Detailed
Theory·····•••·····•••••••••••••••·
600/625
Volt
Low
Voltage
Supply·•·····~··~·-·•••·••••··•••
2800
Volt
Supply
•.............•........•••...•••...•.•..••
High
Voltage
Supply
Operation
At 250
Watts
Output
•••••••
BC-lG Power Change
Facility••··••····••·••·•··•····•·•··
Attachment
of
Remote
Control••••••••·•••·•··•••••••·•••·••••
SECTION
IV.
TUNING
PROCEDURES
Tuning
Procedure,
1000
Watt
Carrier•••·•·····•·•••·•••••••••··
Preliminary
·rune-Up Checks
(Transmitter
Locally
Controlled)
•···•················•••·••·••···········
Checking
Filament
Voltage,
Bias
Supply
and
Low
Voltage
Supply••••••••••••••••••••••••••••••••••••••••
Check Power
Amplifier
Tuning
Components···••·•··••·•······
Neutralizing
the
Power
Amplifier•••••·•••·••·••••••·••••·••·
Neutralizing
with
a
Flashlight
Bulb••·••••••••••••••••••••
Power
Amplfier
Tuning•·••••·•••••··•·••·•••·••·•··•········•
~dulator
Adjustnient
.•.•.•..........•...•••...••••••••.•.•••
Modulation
Monitor
Connections••••••••••••••••••••••••••••••
Method
of
adjustment,
Coil
143
and
Resistor
R34
·•··•••••·•
Tuning
Procedure,
250
Watt
Carrier•··••·····•••••••·••••·•····
Tuning
Procedure,
M5422
Oscillator••••·•··••••••••••••••••••••
SECTION
V.
MAINTENANCE
General·•·············•·••··················•···•····•···•·•·•
Frequency
Adjustment
•••••••••••••••••••••••••·•••••••·••••••••
Transtnitter
Cleanliness
..••..•••••••••.••...•..•••••.•
•.•
••••••
Re
lay
~
Maintenance
•••••••••••••••••••••••••••••••••••••••••••••
Care
of
Printed
Wiring
Boards•••••·•••········•·······••••••••
Cabinet
Ventilating
Fan··••••·····••••••••••••···········••·•·
Test
Equipi:ne.nt
•••••••••••••••••••••••••.•.••••••••••••••••••••
DC
Resistance
Measurements
Modulation
Transformer
AM.-30469E
••••••••••••••••••••••••••••••••••••••••••••
• • • • • • • • •
SECTION
VI.
PARTS
LIST
3-1
3-1
3-1
3-1
3-1
3-2
3-2
3-4
3-5
3-5
3-5
3-5
3-7
4-1
4-1
4-2
4-3
4-4
4-5
4-5
4-7
4-7
4-8
4-8
4-10
5-1
5-1
5-1
5-2
5-2
5-2
5-2
5-2
Introduction
...................•.•...•........................
6-1
SECTION
VII.
DIAGRAMS
Introduction
...............•....•..........
- -
.....
-
...
• •
•.
•
•.
•
7-1
888-0
800-0
02
V
WARNING:
Disconnect
primary
power
prior
to
servicing.

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Table
6-1.
6-2.
6-
3.
6-4.
6-5.
6:-6.
6-7.
6-8.
6-9.
6-10.
6-11.
LIST
OF TABLES
Parts
List
......••......•....
•
.•.••••.•.•.
•
•••..•.••
•
•...•.•.•..
Feedb~ck
Ladder .Asselllhly
..............
~•-••••••••••••••••••••••••
1
kW
Dummy
Antenna
••
•
••••••..••••••••.••••.••
• • •
••••••.••.
•
•••
••
RF
Driver
Printed
Wiring
Assembly
•••
.
••
•
•••••••••••••••••••••••••
Audio
Input
and
Driver
Printed
Wiring
Assembly
.•...••....•..••..
Pane
1
and
Shelf
As
setnb
ly
..............
·
..............••...••.
_
.•.•
PA
Tuning
and
Output
Assembly
••••••••
•••
••
•••
•••
••
•••••
. -.
••
•••••
Transmitter
Assembly
....•.••.•••.••••.
.
••
•
•.•••.•••.•....•.....
. .
280V
Bias
Supply
Board ......................................
..
.......................
~
.............. ~.
625V
Interm:!diate
Supply
Board
and
Components
1
kW
Transmitter
...•.•.••••.•••••••••••••••
•
••••••••
• • •
•.•••..••
2800
Vdc ,·
1/2
Wave
Silicon
Rectifier
••••••••••••••••••••••••••••
V1
888-0800-002
WARNING:
Disconnect
primary
power
prior
to
servicing.
6-2
6-4
6-5
6-6
6-7
6-9
6-13
6- 14
6-17
6-18
6- 19

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)
1-1.
IN'IRODUCTION
SECTION
I
GENERAL
DESCRIPTION
1-2.
It
is
the
purpose
of
_this
technical
manual
to
thoroughly
explain-
·
in
a
clear,
concise
manner,
the
workings
of
the
BC-lG
BROADCAST
TRANSMITTER,
as
well
as
installation
and
operational
information.
The
pictures
show
clearly
all
components
within
the
cabinet.
These
parts
are
adequately
marked
for
easy
reference
back
to
the
parts
list
and
to
the
written
text.
1-3.
1-4.
MECHANICAL
CDNS'IRUCTION
BC-lG
TRANSMITTER
1-5.
The
BC-lG
Transmitter
is
completely
self-contained
in
one
attractive
steel
cabinet
measuring
78"
high,
37
11
wide
and
29
11
deep
w1th
a
full
front
door,
with
its
"shadow
molding"
covering
practically
·
the
complete
front.
This
door
is
hinged
from
the
left
side.
It
requires
33"
of
floor
space
to
swing
open.
Four
large
meters
are
located
on
a
panel
mounted
across
the
top
of
the
cabinet.
Most
of
the
controls
are
mounted
behind
and
hidden
by
this
door;
the
exception
being
the
filament
start/stop,
reset,
plate
off,
low
power
and
high
power
combination
switch
and
neon
indicators.
These
switches
are
mounted
on
the
right
hand
cabinet
corner
post,
protruding
through
an
opening
in
the
door
when
it
is
closed.
1-6.
The
heavy
power
components
are
mounted
on
the
base
of
the
cabinet.
The
low
powered
audio
and
radio
frequency
stages
are
built
on
a
"panel
and
shelf"
assembly,
along
with
the
control
circuitry
and
the
bias
supply.
Mounted
on
the
shelf
portion
of
this
assembly
is
the
multi-winding
filament
transformer
used
to
energize
all
tube
filaments
in
the
silicon
powered
transmitter.
(If
tube
rectifiers
are
used,
two
additional
rectifier
fila-
ment
transformers
must
be
used).
At
the
top
of
this
panel
assembly
are
the
four
sets
of
filament
connectors
which
secure
the
PA
and
modulator
833A
tubes.
The
two
tubes
to
the
front
of
the
transmitter,
V40
and
V41,
are
the
rf
amplifiers;
the
~
two
toward
the
rear,
V42
and
V43,
are
the
modu~ators.
1-7.
This
complete
"panel
and
shelf"
assembly
is
hinged
to
the
right
rear
cabinet
corner
post,
and
held
securely
by
three
captive,
slotted-head
screws
at
the
front
corner
post.
This
feature
allows
this
panel
to
be
loosened,
then
swung
inward
on
its
hinges
to
provide
access
to
the
complete
panel
without
removing
the
right
hand
side
of
the
cabinet.
This
is
of
great
ad-
vantage
if
the
transmitter
is
located
in
a
position
necessitating
other
equipment
to
be
placed
directly
against
the
right
hand
side
of
the
transmitter.
1-8.
All
tuning
controls
are
available
from
the
front
of
the
transmitter.
(Large
front
cabinet
door
must,
of
course,
be
opened).
An
interlocked,
per-
forated
metal
screen
is
mounted
over
the
front
opening
of
the
transmitter,
which
gives
the
utmost
physical
protection
to
the
operating
personnel.
This
screen
is
easily
removable
from
the
cabinet,
allowing
full
access
to
the
inside
of
the
cabinet
from
the
front.
888-0800-002
1-1
WARNING: Disconnect primary power
prior
to
servicing.

www.SteamPoweredRadio.Com
1-9.
One
exhaust
fan
is
located
above
the
833A
power
tubes,
in
the
top
of
the
cabinet,
to
draw
the
heated
air
up
and
out
during
operation.
Two
dis-
posable
air
filters
are
located
in
the
power
portion
of
the
back
cabinet
cover,
through
which
cool
air
is
drawn
into
the
transmitter.
1-10.
The
dummy
antenna
assembly
is
mounted
on
the
left
cabinet
wall,
to-
ward
the
top,
as
viewed
from
the
front.
1-11.
Both
the
back
and
right
hand
side
of
this
transmitter
cabinet
is
re-
movable
for
servicing,
if
required.
1-12.
M5422
OSCILLA'IOR
UNIT
1-13.
This
oscillator
unit
physically
is
6-1/2
inches
wide
including
mount-
ing
flanges,
6-1/2
inches
high,
and
6-3/4
inches
deep,
including
connector
plug.
The
unit
is
mounted by means
of
its
flanged
bottom
on
the
aluminum
vertical
portion
of
the
"panel
and
shelf".
Its
controls
extend
out
through
a
cutout
in
the
front
vertical
panel.
The
oscillator
shield
cove~
held
i~
place
by
one
thumb
screw,
can
be
removed
by
unfastening
and
sliding
.
horizon-
tally
away
from
the
oscillator
chassis.
Connections
to
the
M5422
oscillator
unit
are
made
by
a 8
position
female
plug,
Pl,
at
the
rear.
1-14.
TRANSMITTER
CON'IROLS
1-15.
All
transmitter
tuning
controls
are
available
from
the
front
of
the
transmitter.
The
small
vertical
panel,
which
is
an
integral
part
of
the
"panel
and
shelf"
assembly
located
on
the
right
side
of
the
cabinet,
behind
the
front
door,
has
the
following
controls:
a.
The
crystal
selector
switch,
Sl,
and
the
two
crystal
trimmer
capacitors,
Cl
and
C2. (The
M5422
Crystal
Oscillator
Unit
is
mounted
directly
behind
this
panel.)
Its
controls,
Sl,
Cl
and
C2,
protrude
through
a
small
aperture
in
this
panel,
and
thus,
are
available
from
the
front.)
b.
The
rf
driver
tank
tuning
capacitor,
C4.
c.
Multimeter
switch,
S2.
d.
M:>dulator
cathode
current
selector
switch,
Sl.
e.
Modulator
bias
controls,
Rl
and
R2.
1-16.
The
following
controls
are
located
on
the
right
hand
corner
post
section
of
the
cabinet:
a.
Filament
rheostat,
R43.
b.
Plate
rheostat,
R41.
c.
Filament
On/Off,
S41.
(Red
pushbutton).
1-2
888-0800-002
WARNING: Disconnect primary power
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)
d.
Reset,
S42.
(Red
pushbutton).
e.
Plate
stop,
S43.
(White
pushbutton).
f.
250
Watt
carrier,
S44.
(Amber
pushbutton).
g.
1000
Watt
carrier,
S45.
(White
pushbutton).
h.
Local/Remote
toggle
switch,
S40.
1~17.
A
complement
of
four
large
meters
are
mounted
on
a
panel
at
the
top
of
the
cabinet.
From
left
to
right,
they
are:
a.
Multimeter,
M40
b.
Modulator
cathode
current,
M43.
c.
PA
plate
current,
M42.
d.
PA
plate
volts,
M41.
1-18.
The
line
meter,
M44,
is
mounted
on
the
power
amplifier
panel,
and
·
is
visible
when
the
front
cabinet
door
is
open.
Also
on
this
PA
panel
we
find
the
power
amplifier
tuning
control,
L40,
the
power
amplifier
load
control,
IA2,
and
the
neutralizing
adjustment,
C40.
This
latter
facility
is
a
screw-
driver
adjustment
made
through
a
small
opening
in
the
panel.
It
is,
of
course,
a
seldom
manipulated
control.
1-19.
INCIDENTAL
INFORMATION
1-20.
TUBE
HANDLING
1-21.
The
BC-lG
Transmitter
uses
833A
power
tubes
in
the
power
amplifier
and
modulator
stages.
These
are
of
the
single
wire
or
thread
filament
type,
as
compared
to
other
tubes
which
may
have
the
filament
(heater)
contained
in
a
tube,
which
is
commonly
called
the
cathode
assembly.
Tubes
having
single
wire,
or
thread
type
filaments,
supported
by
springs
(such
as
the
833A)
re-
quire
more
than
normal
care
in
handling.
These
filament
wires
are
easily
broken
by
sudden,
heavy
vibration.
At
all
times
handle
the
tubes
with
care,
until
they
are
safely
inserted
in
the
tube
·
sockets
of
the
transmitter.
1-22.
At
this
point,
more
care
must
be
exercised
in
this
type
of
power
tube,
as
the
filament
prongs
are
also
the
means
by
which
the
tubes
are
secured.
Make
sure
the
filament
connections
have
some
"give"
so
that
no
undue
strain
is
placed
on
the
glass-to11etal
filament
prongs.
As
the
glass
envelope
will
expand
a
bit
during
operation,
the
two
securing
filament
con-
nectors
must
be
free
to
move
themselves.
1-23.
Take
care
when
making
the
grid
and
plate
connections
to
the
tube,
do
not
put
any
undue
strain
on
these
connections
during
tube
installation.
Of
course,
the
connections
to
the
grid
and
plate
should
be
flexible
to
allow
for
expansion
of
the
tube.
For
shipping
or
storing
it
is
advisable
to
use
888-0800-002
1-3
WARNING:
Disconnect
primary
power
prior
to
servicing.

www.SteamPoweredRadio.Com
the
packing
material
and
carton
that
the
tube
was
shipped
in
from
the
tube
manufacturer.
Following
these
reasonable
precautions,
there
should
be
no
trouble
in
handling
these
tubes.
1-24.
TRANSMITTER
BUILDING
TEMPERATURES
1-25.
If
this
transmitter
is
to
be
unattended
(operated
by
remote
control)
care
should
be
taken
that
winter
temperatures
inside
the
transmitter
building
do
not
go
below
50°F.
Mercuxy
vapor
tubes
(if
used)
will
arc
b~ck
at
low
temperatures,
often
causing
severe
damage
-
either
to
themselves
or
to
other
expensive
components.
Protective
relays
and
fan
motors
may
also
become
sluggish
under
extremely
cold
conditions
.
Failure
to
provide
ade-
quate
winter
minimum
building
temperatures
will
void
the
guarantee.
1-26.
raoUNDING
1-2
7.
The
grounding
of
the
transmitter
installation
is
of
major
impor-
tance.
Remember,
it
is
a
part
of
your
radiating
system.
It
can
be
safely
assumed
that
the
better
the
complete
ground
system,
the
more
efficient
will
be
the
radiating
system.
A
lack
of
complete
grounding
of
the
transmitting
and
audio
equipment
may
cause
trouble
from
stray
rf
getting
into
the
audio,
and
may
cause
unstable
transmitter
performance,
etc.
It
is
wise
to
bond
all
electrical
conduit,
water
piping,
metal
building
framework
to
the
overall
ground
system.
If
these
suggestions
are
followed,
there
will
be
less
trouble
over
the
years,
as
the
ground
system
ages.
1-28.
ANTENNA
OOUPLING
1-29.
Antenna
coupling
equipment
not
involved
in
these
instructions
is
a
very
important
part
of
the
entire
successful
operation.
The
instructions
supplied
with
the
antenna
coupler
will
aid
in
its
adjustment.
As
all
radi-
ating
towers
must
be
measured
electrically
by
an
approved
engineer,
be
could
check
and
advise
on
the
tune-up
of
the
antenna
coupler.
If
your
operation
is
directional
the
engineer
will,
of
course,
tune
the
entire
directional
system,
which
includes
the
antenna
coupling
equipment.
1-30.
TECHNICAL CHARACTERISTICS
RATES
POWER
OUTPUT:
FREQUENCY
RANGE:
PRIMARY
POWER
INPUT:
FREQl.JENCY
STABILITY:
1000/250
watts.
capable
of
1100/275
watts,
if
necessary,
to
overcome
possible
losses
in
directional
arrays.
2000
kHz
to
540
kHz
230
volts,
3
wire,
solid
neutral,
single
phase
50
to
60
Hz.
Approximately
3850
watts
con-
sumed
at
100%
tone
modulation,
at
1000
cycles.
+5
Hz
within
temperature
range
of
50
to
122°F.
1-4
888-0800-002
WARNING:
Disconnect
primary
power
prior
to
servicing.

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\
)
ELEVATION:
VENTILATION
NE
CFS
SARY:
AUDIO
INPUT:
INPUT
AUDIO
IMPEDANCE:
FREQUENCY
RESPONSE:
DISTORTION:
NOISE:
CARRIER
SHIFT:
RF
OUTPUT
IMPEDANCE:
DUMMY
ANTENNA:
TUBES
USED:
OPTIONAL
TUBE
RECTIFIERS
IF
USED:
CRYSTAL5
EXPORT
PACKING
INFORMATION
6500
feet.
Provision
should
be
made
to
allow
1500
CFM
of
clean,
outside
air
under
all
circumstances.
16
dB,
_:2
dB, ·
for
100%
modulation
for
both
output
powers.
As
supplied,
600 ohms,
which
will
also
serve
to
match
500 ohms ·
satisfactorily.
Input
may
be
connected
for
150/250
ohms,
if
desired.
+1.5
dB,
30
to
12,000
Hz
Rated
at
3%
from
50
to
10,000
Hz,
at
95%
modulation.
60 dB,
or
better,
between
O
and
100%
modulation.
3%
or
less,
between
0
and
100%
modulation
Will
match
resistive
loads
from
50
to
70
ohms.
51.5
ohms,
built
in
(2)
12BY7A,
Osc.
&
1st
IPA
(6)
807,
Audio
& 2nd
IPA
(4)
833A, Power
.Amp.
&
Modulators
Silicon
rectifiers
are
used
in
bias,
inter-
mediate
voltage
and
high
voltage
supplies.
(2)
866A,
Low
Voltage
Rectifiers
(2)
8008,
High
Voltage
Rectifiers
Vacuum,
ovenless,
octal
based
-
Provision
for
two.
Product
: BC-lG
No.
of
Pkgs:
4
Gross
Wt:
1400
Cuhage:
102.
3
Largest
Box:
39
x
47
x
84
888-0800-002
1-5/1-6
WARNING
:
Di
sc
onnect
primary
power
prior
to
servic
i
ng.

www.SteamPoweredRadio.Com
)
_.,-
2-1.
GENERAL
SECTION
II
INSTALLATION
2-:
.•
This
section
cont~ins
information
for
personnel
installing
and
oper-
ating
the
BC-lG
Transmi.tter.
The
following
mentioned
points
should
be
st?died
so
that
the
unpacking
and
set
up
procedure
will
be
well
in
mind
when
dqing
the
actual
work.
2-3.
2-4.
INSTALLATION
INSTALLATION
HINTS
a.
Check
all
packing
lists
for
materials
supplied.
b.
Study
the
technical
manual
before
attempting
to
set
up
the
equip-
ment.
c.
Have
the
transmitter
location
clean
so
that
the
various
parts
can
be
safely
placed
out
of
harms
way
when
the
unit
is
unpacked.
d.
It
is
well
to
have
a
mounting
base
set
in
place
upon
which
the
transmitter
can
be
set.
This
base
can
be
made
from
2
11
x
4"
lumber.
It
should
be
lagged
to
the
floor
and
measures
taken
to
insure
that
the
top
side
of
the
frame
is
perfectly
level.
This
will
give
a
good,
solid,
level
base
on
which
the
transmitter
can
be
set.
This
procedure
also
allows
the
external
transmitter
wiring
to
enter
the
cabinet
from
practically
any
point
underneath
and
be
run
to
the
entry
holes
provided
in
the
base
of
the
cabi-
net.
See
drawing
813
7924
001
for
base
layout
and
dimensions.
e.
Use
heavy
primary
wire
from
the
building
switchbox
terminals
to
the
transmitter
fuse
block.
#4
copper
wire
should
be
suitable
for
these
leads.
f.
Be
sure
the
power
company
has
installed
large
enough
service
for
all
the
equipment;
transmitter
lights,
water
pump
etc.,
which
will
be
used
at
the
transmitter
site.
g.
Do
a
good
job
of
installing
the
equipment.
Time
spent
in
making
the
installation
as
good
electrically
and
mechanically
as
possi-
ble,
will
pay
off
in
the
future
by
insuring
less
off-the-air
time.
2-5.
'lllANSMITTER
INSPECTION
2-6.
All
packing
material,
string.
tape,
etc.,
should
be
removed.
All
re-
lays
should
be
inspected
for
free
travel
of
armature
and
contacts.
Heavy
components,
such
as
the
high
voltage
power
transformer,
high
voltage
swinging
choke,
modulation
transfonner
and
modulation
choke
are
shipped
sep-
arately,
each
in
its
own
box.
888-0
800-0
02
2-1
WARNING:
Di
sco
nnect orim~rv
nnw<>r
nrin
r
tn
c-o,_,
;
,.
;
,_~

www.SteamPoweredRadio.Com
2-7.
Tubes
and
crystals
are
packed
separately.
shipped
in
its
socket,
on
have
also
been
removed
from
transmitter,
The
small,
glass
enclosed
time
delay
the
panel
and
shelf
assembly.
these
too
relay
is
2-8.
Go
over
the
complete
transmitter.
After
traveling
a
long
distance
a
fastener
could
come
loose.
Put
a
screwdriver
or
wrench
to
all
nuts
and
bolts.
This
work
may
take
an
hour
or
so,
but
may
save
loss
of
air
time
later
on.
2-9.
TRANSMITTER
CONNECTIONS
2-10.
After
the
transmitter
has
been
uncrated
and
placed
in
its
final
oper-
ating
position,
the
external
connections
can
be
made
to
it.
These
connec-
tions
will
be
outlined
and
each
one
will
be
gone
over
in
detail.
2-11.
PRIMARY
POWER.
This
·
line
will
supply
the
power
requirements
of
the
transmitter.
For
good
regulation
the
wire
size
is
important.
We
have
sug-
gested
#4
wire
from
the
wall
switch
box
to
the
transmitter.
This
service
calls
for
the
three
wire,
230
volt
installation;
in
other
words,
115
volts
each
side
of
a
solid
neutral.
The
two
hot
wires
should
be
#4,
the
neutral
can
be
smaller
in
size,
if
desired,
but
in
no
case
smaller
than
#8.
These
wires
can
be
brought
into
the
cabinet
at
the
right
hand
rear
corner
(as
viewed
from
the
front).
Make
sure
the
wall
switch
is
in
the
OFF
position.
Connect
the
three
primary
wires
to
the
transmitter
fuse
block
XFl.
2-12.
TRANSMITTER
GROUND.
A
large
ground
stud
is
located
on
the
cabinet
frame
very
close
the
the
modulation
transfonner,
T41.
Connect
a
good
ground
strap
from
this
stud
to
the
ground
syste
_m
of
the
station.
A
copper
strap
1
11
or
2"
in
width
will
do.
Tbs
strap
may
enter
the
cabinet
through
the
access
hole
in
the
base
at
the
right
rear
through
which
the
ac
primary
wires
enter.
2-13.
AUDIO
INPUT. The
audio
input
pair
should
be
in
shield,
the
two
audio
wires
should
be
connected
to
terminals
#14
and
#15
on
TB2. The
cable
shield
can
be
grounded
on
terminal
#13
of
TB2.
2-14.
MODULATION
MONITOR.
The
modulation
monitor
should
be
connected
to
tenninals
#13
and
#14
of
TBlA.
Solid
dielectric
coaxial
cable,
such
as
RG62/U
can
be
used
for
this
connection.
TBlA-14
is
the
"Hot"
wire,
TBlA-13
is
ground.
2-15.
FREQUENCY
MONITOR.
The
frequency
monitor
should
be
connected
minals
#30
and
#29
(29
ground)
on
TB2.
This
connection
can
also
be
on
RG62/U
coaxial
cable,
the
center
wire
connecting
to
terminal
#JO.
the
shield
to
#29.
to
ter-
ma
_cje up
Ground
2-16.
RF
OUTPUT.
Connect
the
coaxial
transmission·
line
center
conductor
the
ceramic
feedthru
insulator
stud.
This
feedthru
insulator
is
located
near
the
output
loading
coil,
IA2.
You may
run
the
coaxial
line
either
through
the
top
of
the
cabinet,
through
a
hole
provided
there,
or
up
through
the
base.
In
any
event,
be
sure
the
outer
shield,
·
or
conductor
is
totally
grounded
to
the
transmitter
cabinet
and
to
the
station's
ground
system.
7-2
888-0800-002
WARNING:
Disconnect
primary
power
prior
to
servicing.

www.SteamPoweredRadio.Com
-)
/I
)
2-17
RF.MOT
• E
OON'IROL
(
IF
USED)
controlled
using
RDC-10 •
If
the
transmitter
is
.
used
for
making
the
conn~cr:~ote
equipment,
the
followingg~~ng
to
?e
remotely
ions.
OI'1Jlat1on
must
be
2~18
Detailed
Instructions
f
ties
already
available
in
the
o;C
R:;ot~
Co_ntrol
Connections.
With
faci11.·
remote
RESET a d
c1.rcu1.try
f . -
. n
remote
plate
OFF . t .
or
remote
filament
ON/OFF
install
the
small
motor
assembl
~
i
is
only
necessary
for
the
customer
•
supplemental
re
lay
KIA
wh.
h
y
o
actuate
the
plate
·
rheostat
R41 d
to
ic
operates
the
250/lOOO
w
tt
.
an
the
2· a
carrier
function
-19.
Plate
Rheostat
Moto
As b •
#994
6326
001
has
full
mech:nicaslem.
;f•
1'l;e
plate
rheostat
motor
assembl
for
easy
installation
in
the
t
i
_ormation
supplied
with
the
kit
to
allo~
chai
·
ransmitter
suitabl
b
n
are
included.
With
th·
• e
rackets,
sprockets
and
the
following
connections
m
t1.sb
motor
and
associated
components
installed
TBl
us
e
run
from
th
b •
,
to
the
RDC-lOC
Transmitter
Control
Unit.
e
motor
racket
terminal
board
a.
b.
c.
d.
e.
f.
Tenninal
#1
connects
to
TB2-26
in
RDC-IOC
unit.
Terminal
#2
connects
to
cabinet
ground
stud.
Tenninal
#3
connects
to
.TB2-28
in
RDC-lOC
unit.
Terminal
#4
connects
to
TB2-17
in
RDC-lOC
unit.
Terminal
#5
connects
to
cabinet
ground
stud.
Connect
a
wire
from
TBl
4 .
th
RDC
. -
in
the
BC-lG
Transmitter
1:0
TB2-27
in
e
-lOC
Transmitter
unit.
This
connection
carries
hot
115
v?lt~
ac
to
the
transmitter
unit
from
the
Fl
side
of
the
line
w1.th1.n
the
~C-lG
Transmitter.
(115
volt
ac
between
TBl-4
of
BC-lG
transmitter
and
ground).
2-20.
Remote
Power
Change.
The
BC-lG
has
in-built
provisions
to
change
power
from
1000
watts
to
250
watts and back
to
1000
watts.
The
two
power
change
contactors
K2
and
K3,
working
in
conjunction
wit:h
plate
auxiliary
re
lay
K9,
and
the
front-of-cabinet
pushbutton
switches
marked
"Reset"
542.
"Plate
Off"
S43,
"Low
Power"
S44
and
"High
Power"
S45,
perform
the
function
of
changing
carrier
power.
Suppose
we
are
operating
at
1000
watt
carrier
power
and
wish
to
drop
carrier
power
to
250
watts,
the
sequence
of
switching
is
as
follows.
2-21.
S43,
the
"Plate
Off"
button
is
depressed,
causing
auxiliary
plate
re-
lay
K9,
~o
drop
out;
its
contacts
A-Band
C-D
open.
Contacts
A-B
control
ac
voltage
to
low
and
high
power
contactors
K3
and
K2.
(As
we
were
on
1000
watts,
the
high
power
contactor
K2
deenergizes,
removing
primary
voltage
from
the
high
voltage
power
transformer
T40),
the
carrier
is
now
off.
"Reset"
button
S42
is
then
momentarily
depressed,
again
setting
up
and
locking
in
auxiliary
relay
K9.
This
operation
then
makes
it
possible
to
select
the
low
power
contactor
K3,
by
depressing
"Low
Power"
button
S44
888-0800-002
2-3
WARNING:
Disconnect
primary
power
orior
to
!':P.rvir-inn

www.SteamPoweredRadio.Com
momentarily.
C.Ontactor
K3
pulls
in,
energizing
the
primary
of
high
voltage
power
transformer
T40,
with
115
volts
ac.
This
action
along
with
several
other
circuit
changes
(all
made
by
contactor
K3)
allows
the
BC-lG
to
operate
on
250
watts
carrier
power.
2-22.
By
Remote
control,
these
power
change
functions
are
performed
as
follows:
a.
Place
switch
Sl,
function
switch,
on
the
front
panel
of
the
RDC-lOC
Studio
Unit
to
position
#2.
The
remote
plate
_
current
meter
will
read
plate
current.
b.
Place
switch
S6,
the
plate
On/Off
switch
on
the
front
panel
of
the
RDC-lOC
Studio
Unit,
to
its
"Off"
position
momentarily,
this
will
de-energize
auxiliary
plate
relay
K9,
in
the
transmitter.
The
transmitter
is
now
off
the
air,
the
remote
.
plate
current
meter
should
read
zero.
c.
Place
the
plate
ON/OFF
switch
S6,
of
the
Studio
Unit,
momentarily
to
its
ON
position.
This
energizes
the
coil
of
auxiliary
relay
K9,
causing
it
to
again
lock
in
and
at
the
same
time
providing
230
volts
ac
for
possible
use
by
K2
or
K3
contactors.
d.
Now
operate
the
Raise/Lower
switch
S4,
on
the
panel
of
the
RDC-lOC
studio
unit.
"Raise"
for
high
power,
"Lower"
for
low
power.
Assuming
1000
watt
carrier
operation
is
desired,
S4
will
be
placed
momentarily
in
its
"Raise"
position.
This
will
com-
plete
the
circuitry
to
the
coil
of
high
power
contactor,
K2,
causing
it
to
pull
in
and
lock,
putting
230
volts
ac
on
the
pri-
mary
of
high
voltage
power
transformer,
T40.
2-23.
The
following
connections
must
be
made
between
the
BC-lG
Transmitter
and
the
RDC-lOC
Transmitter
unit,
to
perform
this
high
power/low
power
func-
tion.
It
will
use
stepper
position
#2.
2-24.
A
supplemental
6
volt
de
relay
KlA,
having
two
sets
of
"A"
contacts
must
be
installed
in
the
BC-lG
Transmitter,
this
relay
is
included
in
remote
control
kit
#994
6326
001.
This
relay
will
be
mounted
in
the
space
provided
on
the
"Panel
and
Shelf",
see
drawing
813
7961
001
for
physical
location
of
supplemental
relay
KlA,
also
drawing
813
7928
001
f.
or
KlA
connections.
These
connections
are
as
follows.
a.
Coil
KlA-1
.
connected
to
TBl-20
in
BC-lG.
b.
Coil
KlA-2
connected
to
TBl-26
in
BC-lG.
c.
KlA-5,
normally
open
contact,
is
connected
to
TBlA-15
in
BC-lG
Transmitter.
d.
KlA-4,
normally
open
arm,
is
connected
to
TB2-6
in
BC-lG.
e.
KlA-8,
notmally
open
contact
is
connected
to
TBl-30
in
BC-lG
Transmitter.
2-4
888-0800-002
WARNING:
Disconnect
primary
power
prior
to
servicing.
---
)

www.SteamPoweredRadio.Com
f. KlA-7, normally open arm connects to TB2-8 in BC-lG Transmitter.
2-25. With the supplemental relay KlA instailed and connected, the external
connections to the RDC-lOC Transmitter Unit can be made:
a. TBl-30 in BC-lG must connect to TB2-28 in RDC-lOC Transmitter
Unit.
b. TBlA-15 in BC-lG connects to TB2-26 in RDC-lOC Transmitter Unit.
c. TBl-20 in BC-lG connects to TB2-25 in RDC-lOC Transmitter Unit.
d. TBl-26 in BC-lG connects to TB2-16 in RDC-lOC Transmitter Unit.
•.
NOTE
These functions make use of stepper
position #2.
2-26. Reset, Plate Off (Setting Up Auxiliary Relay K9). Three connections
must be made between the BC-lG Transmitter and the RDC-lOC Transmitter
unit. They are:
a . TB2-3 in BC-lG must connect to TB2-29 in RDC-lOC Transmitter Unit.
b. TB2-4 in BC-lG connects to TB2-30 in RDC-lOC Transmitter Unit.
c. TB2-5 in BC-lG must connect to TB5-2 in RDC-lOC Transmitter Unit.
NOTE
A jumper must be added in the RDC-lOC
Transmitter Unit, from TB2-30 to TBS-1.
2-2 7. Remote Plate Voltage Indication. There are two connections which
must be made between the BC-lG transmitter and the RDC-lOC transmitter unit .
a. The positive terminal of the plate voltage extension in the BC-lG
transmitter, TB2-9 must be connected to TB2-l in the RDC-lOC
Transmitter Unit.
b. The negative terminal of the plate voltage extension in the BC-lG
transmitter, TB2-10 must be connected to TB2-25 in the RDC-lOC
Transmitter Unit.
NOTE
This function is on position #1 of the
RDC-lOC Studio Unit.
2-28. Remote Plate Current Indication. There are two connections which
must be made between the BC-lG Transmitter and the RDC-lOC Transmitter Unit.
888-0 800-0 02
2-5
WARNING: Disconnect primary power prior to servicing .