Magnavox CMX 49545 User manual
-,
r------------*----------..,
NAVSHIPS
900,853
INSTRUCTION
BOOK
for
SPEAKER-AMPLIFIER
NAVY
TYPE
CMX
49545
Ma,mfactrtred for
U.
S.
NAVY DEPARTMENT BUREAU OF SHIPS
6,
THE MAGNAVOX COMPANY
Fort Wayne, Indiana
I
--
_____
-----*----------~
r----------------------*---------------------,
NAVSHIPS
900,853
INSTRUCTION
BOOK
for
SPEAKER
-AMPLIFIER
NAVY
TYPE
CMX
49545
lHallufaClm'ed
for
U.
S.
NAVY
DEPARTMENT
BUREAU
OF
SHIPS
by
THE
MAGNAVOX
COMPANY
Fort
Wayne,
Indiana
L-
_____________________
*
____________________
~
CONTRACT
NXsr
93879
Approved 1
JULY
1946
NAV5HIP5
900,853
Front
Matter
A
I
c
,
Front
Matter
NAVSHIPS 900,853
~DDRESG
NAvY DEPARTMENT.
BURPU
OF
SHIpS
NAvY
DEPARTMENT
Section
993-10
0
RD"ER
TO
FlU;:
NO.
BUREAU
OF
51-UPS
WASHINGTON
25.
D.
Co
ORIGINAL
27
June
1946
To,
All
Activities
concerned
with
the
Installation,
Operation
and
Maintenance
of
the
subject
"Equipment.
SUDj'
Instruction
Book
for
Speaker-Amplifier
Navy
Type
CMX-49545 (NAVSRIPS
900,853).
1.
NAVSRIPS
900,853
is
the
instruction
Dook
for
the
sUDje
ct
equipment
and
is
in
effect
upon
receipt.
2.
When
superseded
DY
a
later
edition,
this
publication
shall
be
destroyed.
3.
Extracts
from
this
pUDlication
may
be
made
to
facilitate
the
preparation
of
other
Navy
instruction
books
and
handbooks.
4.
Copies
of
this
pUDlication
may
be
oDtained
from
the
nearest
ElectronicS
Officer.
E.
L.
cocRIWIE
Chief
of
Bureau
"",,,
BUREAU
OF
sHIPS.
NAVV
DEPARTMENT.
WASHINGTON
2'.
D.
C.
B
NAVSHIPS 900,853
Front
Matter
Change
No.
Dale Signature
of
Officer
Making
Correction
.,
c
NAVSHIPS
900,853
TABLE
OF CONTENTS
Paragraph
Contractual Guarantee
Report
of
Failure
SECTION
I - General Description
Suh;ect Page
. . . . . . . . . . . . . . . . . iii
iv
I-I
1 Function .
..........
.
.....................................
I-I
I-I
I-I
I-I
I-I
2
3
4
5
Reference Data
Equipment Supplied
Equipment
Required But
Not
Supplied
Vacuum Tube Complement
...
SECTION
II-
Theory
of
Operation
I
Theory
of
Operation
SECTION
III
-Installation
and
Initial Adjustments
2
3
Unpacking
Installation
Initial Adjustments
.....
SECTION
IV
-
Operation
2-0--2-1
.................................
2~
3-0--3-1
4-0
3-0
3-0
3-1
1 Operation .
.............................................
. 4-0
SECTION
V - Maintenance
5-0--5-11-5-12
1 Operators Maintenance
..............
5-1
2
3
Preventive Maintenance
Corrective Maintenance
.......................................................
5-1
5-1
SECTION
VI
-Parts
and
Spare Parts Lists
......................................
6-1----{)-8
NA
VSHIPS
900,853
LIST OF ILLUSTRATIONS
Figure
1·1 Speaker.Amplifier CMX·49545
................................................
. 1·0
4-1 Lower Front Panel
...........................................................
. .w
5·1 Speaker.Amplifier CMX·49545 -
Top
Chassis View
..............................
. 5·2
5·2 Speaker.Amplifier CMX·49545 -Lower Chassis View
............................
.
5'3
5·3 Speaker.Amplifier CMX·49545 -Lower Chassis View
............................
. 5-4
5-7 Parts For Cone Replacement
..................................................
. 5·9
5·8 Completed Cone Replacement
.................................................
. 5·9
LIST OF
DRAWINGS
Figure
Page
2·1 Functional Block
Diagram
....................................................
. 2·1
3·1
Main
Terminal
Board
Diagram
................................................
3·0
5·4
Audio
Frequency Curve
.......................................................
5·5
5·6
5·7
5·5
5·6
5·9
Cable Connection Diagram
Schematic Circuit Diagram
Amplifier
Wiring
Diagram
..............................................
5·11-5·12
LIST OF
TABLES
Table No.
6·1
Major
Unit
.........................................................
.
6·2
6·3
Combined Parts
and
Spare Parts Lists by Symbol Designations
List
of
Parts by
Navy
Numbers
................................................
.
6-4 Applicable Resistor Color Codes
..............................................
.
6·5 Applicable Capacitor Color Codes
.............................................
.
6-6 List
of
Manufacturers
.......................................................
.
Pllge
6-1
6-1
6·4
6·6
6·7
6-8
,
•
•
•
•
NAVSHIPS 900,853
CONTRACTUAL
GUARANTEE
The
Contractor
guarantees
that
at
the
time
of
delivery
thetof
the
articles
provided
for
under
this
contract will
be free
from
any defects
in
material
or
workmanship
and
will
conform
to
the
requirements
of
this
contract. Ex-
cept as
to
vacuum tubes, batteries,
rubber
and
material
normally consumed
in
operation,
the
equipment, includ-
ing
all spare parts, is
guaranteed
for
a
period
of
one
year
from
the
date
of
its delivery
to
and
acceptance
by
the
Government,
with
the
understanding
that
all items
found
to
be defective as
to
material,
workmanship
or
manufacture will be repaired
or
replaced, f.a.b. any
point
within
the
continental
United
States designated
by
the
Government,
without
delay
and
at
no
expense
to
the
Government;
provided,
that
such
guarantee
shall
not
obligate
the
Contractor
to
repair
or
replace any
such defective items unless
the
defect appears
within
the
aforementioned
period
and
the
Contractor
is noti-
fied
within
a reasonable time
and
unless
the
defect
is
not
the
result
of
normal
expected shelf life deteriora-
tion.
This
guarantee
shall
then
continue
as
to
corrected
or
replacing articles
or,
if
only
parts
of
such are cor-
rected
or
replaced,
to
such corrected
or
replacing parts,
until
one year
after
the date
of
redelivery.
To
the
extent
the
equipment,
including
all parts
and
spare parts, as defined above,
is
of
the
Contractor's
de-
sign
or
is
of
a design selected
by
the
Contractor,
it
is
also guaranteed, subject
to
the
foregoing
conditions,
against defects
in
design,
with
the
understanding
that
if
ten percent
or
more
of
the
total
quantity
comprising
such item furnished
under
the
contract
(but
not
less
than
two
thereof)
is
found
to
be
defective as
to
design,
the
entire item
will
be conclusively presumed to
be
of
defective design
and
shall
be
subject
to
one
hundred
percent correction
or
replacement by a suitably rede-
signed
item.
All defective items will be subject
to
ultimate return
to
the
Contractor
except
that
the
exigencies
of
the
naval
service may necessitate expeditious repair
of
certain
items in
order
to
prevent
extended
interruption
of
com-
munications
and
in
such cases
the
return
of
the defec-
tive items
for
examination by
the
Contractor
prior
to
repair
or
replacement shall be mandatory.
The
report
of
a responsible authority, including details
of
the
con-
ditions
surrounding
the
failure,
will
be acceptable as a
basis
for
effecting expeditious
adjustment
under
the
provisions
of
this contractual guarantee.
If
the
Government
does
not
require correction
Or
re-
placement
of
a defective
or
nonconforming
article, the
Contractor,
if
required by the contracting officer within
a reasonable time after
the
notice
of
defect
or
noncon-
formance, shall repay such
portion
of
the
contract price
as
is
equitable
in
the circumstance. Equitable
in
the cir-
cumstance is
to
be determined by mutual agreement be-
tween
the
Contractor
and
the
contracting officer. Failure
to
agree
to
such
adjustment
shall be a dispute concerning
a question
of
fact
within
the
meaning
of
the
section
of
this contract
entitled
"Disputes".
iii
iv
NAVSHIPS 900,853
REPORT OF FAILURE
Report
of
failure
of
any
part
of
this equipment,
during
its service life, shall be
made
to
the Bureau
of
Ships
in
accordance
with
current
instructions.
The
report
shall cover all details
of
the
failure and
give
the
date
of
installation
of
the equipment.
For
procedure
in
reporting
failures see
Chapter
67
of
the
Bureau
of
Ships
Manual,
or
superseding instructions.
CONTRACT:
NXsr
93879
DATE
OF
CONTRACf:
2
APRIL
1945
SERIAL
NUMBER
OF
EQUIPMENT
___________________
_
DATE
OF
ACCEPTANCE
BY
THE
NAVY
________________
_
DATE
OF
DELIVERY
TO
CONTRACf
DESTINATION
____________
_
DATE
OF
COMPLETION
OF
INSTALLATION
______________
_
DATE
PLACED
IN
SERVICE
_____________________
_
Blank
spaces
in
this
book
shall
be
filled in at time
of
installation.
Operating
personnel shall also
mark
the
"date
placed
in
service"
on
the
date plate located below
the
model nameplate
on
the
equip.
ment, using suitable methods
and
care
to
avoid
damaging
the equipment.
All requests
or
requisitions
for
replacement material
should
include the
following
data:
1.
Name
of
part
desired.
2.
Navy
stock
number
or,
when
ordering
from
an
Army supply depot,
the
Army stock number.
If
the
Navy
stock
number
has
not
been assigned,
the
requisitions
should
specify the following:
1.
Equipment
model designation.
2.
Name
of
part
and
complete description.
3. Manufacturers designation.
4. Contractors
drawing
and
part
number.
5. AWS,
JAN,
or
Navy
type designation.
SAFETY
NOTICE
The
attention
of
officers
and
operating
personnel
is
directed
to
Chapter
67
of
Bureau
of
Ships Man-
ual
or
superseding instructions
on
the
subject
of
Radio-Safety precautions
to
be observed.
l'
•
NAVSHIPS
900,853
)
Fi!lure
I-I
5
< •
peaker-Amp/ifier
-
Navy
Type
CMX
49545
1-0
r
General
Description
NAVSHIPS
900,853 Section 1
Paragraphs
1-5
SECTION
I
GENERAL
DESCRIPTION
1.
FUNCTION.
The
navy type
CMX·49545
Speaker.Amplifier is de-
signed
for
high-fidelity
reproduction
of
speech
and
music
when
used
with
the
navy
model
RBO
Radio
Receiving
equipment
for
entertainment
purposes
aboard
all types
of
Naval
vessels
or
at
Naval
shore
radio
sta-
nons
or
activities.
2.
REFERENCE
DATA.
a.
Nomenclature-Navy
Type
CMX·49545 Speaker·
Amplifier.
h.
Contract-NXsr
93879
dated
2
April
1945.
c.
Contractor
-
The
Magnavox
Company,
Fort
Wayne,
Indiana.
d.
Cognizant
Naval
Inspector-Inspector
of
Naval
Material,
Detroit,
Michigan.
3. EQUIPMENT SUPPLIED.
Quantity
per
Name
0/
Navy
Unit
e.
Number
of
Packages
per
Equipment-Main
unit,
one
box; Spare Parts, one box.
f.
Total
Cubical
Contents-Main
unit, crated,
4Vz
Cll.
ft.,
uDerated,
1%
cu.
ft.;
Spare Parts,
total
2¥2
cu. ft. crated.
g.
Total
Weight-Main
unit, crated, 100 Ibs.,
un-
crated 60 lbs.; Spare Parts, crated, 70 Ibs.
h.
Frequency
Range-100·5000
cps.
i.
Rated
Output-3
Watts.
j.
Voltage-1l5
V
AC±I00/
o, 50-60 cps, 50
Watts,
single phase.
k.
Input
Impedance-620
Ohms±IO%,
balance4
or
unbalanced
to
ground.
Overall Dimension
Volume
Weight
A:
Crated
A:
Crated A: Crated
Equipment Designation B: Uncrated B: Uncrated B: Uncrated
1 Speaker-
CMX
49545
A,
27" x 19"
xIS"
A:
4%
cu. ft.
A,
100
lb
•.
Amplifier
B:
190/4" x 14" x 11"
B:
1%
cu. ft.
B,
60 Ibs.
1 set
Equipment
A:
23%"
x 15lj4" x 12lj4"
A:
2%
cu. ft.
A,
70 lbs.
Spares
B:
18lj2" x
12%"
X
9lj2"
B:
11;4
cu. ft.
B,
46
lb
•.
4.
EQUIPMENT REQUIRED BUT
NOT
SUPPLIED.
Qutmtity
Name
0/
Navy
Type
Required
per
Equipment
Unit
Designation Characteristics
1 Radio Receiving Model
RBO
600
ohm
output
impedance;
6
milliwaus
to
2
watts
audio
output
Equipment
Power
Input
Cable
Interconnecting
Cable
5.
VACUUM
TUBE COMPLEMENT.
Each
of
the
Speaker.Amplifier units as
shipped
is
equipped
with
its full
complement
of
vacuum tubes as follows:
Type Quantity
Amplifier
JAN
6V6GT/G
3
Rectifier
JAN
SY3GT/G
1
1·1
Section 2
Paragraph
1
NAVSHIPS
900,853
Theory
of
Operation
SECTION
II
THEORY OF OPERATION
I.
The
CMX·49545
SPEAKER·AMPLIFIER
consists
of
a two-stage
audio
amplifier
with
power
supply,
and
a magneto-dynamic loudspeaker, all contained
in
a cast
aluminum case.
The
amplifier consists
of
a voltage-amplifier stage
using a
JAN
6V
GGT
/G
vacuum tube; a
push.
pull
class
"AU
power
output
stage using
two
JAN
6V6GT/G
vacuum tubes;
and
a
power
supply using a JANSY3-
GT
/G
high·vacuum rectifier tube,
and
furnishing
all
filament, plate,
and
grid
voltages necessary
for
opera-
tion
from
115 volt, 60 cps, single phase
alternating
current
power
lines.
Figure 2-1 is a functional block diagram
of
this
equipment.
The
amplifier
unit
is
arranged
to
select
anyone
of
five 600
ohm
input
channels by
the
proper
setting
of
the
channel selector switch (S-102) which is adjustable
from
the
front
of
tbe
panel.
The
unused channels are
terminated
with
resistors
(R-I0l
to
R-I05,
incl.).
The
input
to
the
grid
of
the
voltage-amplifier tube
(V.101)
is
variable by means
of
a
potentiometer
(R·106)
having a logarithmic taper, which may
be
adjusted
from
the
front
of
the
panel
to
give
the
desired
audio
output.
The
tuned-filter type
tone
control
circuit
is
inserted
2-0
between the voltage amplifier
and
the
power
amplifier
and
the
tone may be regulated by means
of
a potentiom-
eter
(R·112),
adjustable
from
the
front
of
the
panel,
to
give
the
des_ired
audio response.
The
tone
control
circuit
is
composed
of
an
inductance
(L-I02),
three
capacitors
(C-108, C·109,
and
C·ll0),
and
the
potentiometer
(R·112).
The
power
amplifier stage incorporates a negative-
feedback circuit
(R.l13,
R·114, R.115, R·116,
GIll,
and
C-1l2)
to
give a better audio response
and
to
reduce
distortion.
The
power
supply stage
is
a conventional circuit
w-
ing
a high·vacuum rectifier tube
(V·104)
and
a single
PI-section inductance-capacitance
(L-I0l,
C-I07A,
and
C·107B) filter.
The
loudspeaker is a moving coil type speaker using
a
permanent
magnet
to
furnish
the
magnetic flux.
The
moving
coil has
an
impedance
of
3.7 ohms
at
1000
cps,
which
is matched
to
the
load
resistance
of
the
power
amplifier tubes by means
of
a
transformer
(T·103)
mounted
on
the
amplifier chassis.
The
cast aluminum case,
housing
the
amplifier
and
loudspeaker, forms a vented-bafile type acoustic chamber
for
improved reproduction
of
low-frequency tones.
•
':'
~
...
,0.
e:
~
..
•
...
e:
~
~
ir
~
!!.
'"
0-
~
o
ir
~
.,
~
~
r--
...
---
_..
-_
..
FROM
G
V-101
...
INPUTS I
~SOl
:
I i II
I6
V6-
GT
I.
_
1&
\
1_.
INPUT VOLUME
SELECTOR
OONTROL
S-102
R-10e
LEGEND:
ti-
~
STAGE
NS.
r-
L-l02
C-l01
T-l
C-l01
:
C-110
I
I
""---
TONE
OONTROL
R-Ut
r-
3
i.
VARIABLE OONTROLS ARE INDIOATED
BY
A OIROLE AND A DOTTED
LINE
SHOWING
POINT
IN
OIROUIT WHERE
THEY ARE OONNEOTED.
2_
LETTERS
AND
NUMBERS OUTSIDE TUBE
BLOOKS INDIOATE TUBE
ELEMENT
·AND
SOOKET PIN.
3_
HEAVY LINES AND
ARROW
HEADS
INDIOATE DIREOTION
OF
ENERGY
FLOW_
G
POWER
AMPLIFIER
V-102
P
'5
6V6-GT
IT
POWER
AMPLIFIER
G
V-103
P
"'i
eVe-GT
t'3
.,
INVERSE FEEDBAOK
•
.,
01
n
ER
,-
'"101
LS-iOi
~
SPEAKER AMPLIFIER
CMX-49545
FUNCTIONAL BLOCK DIAGRAM
...
:r
CD
0
-<
0
-
0
"
CD
~
Q
::
0
"
z
>
<
.,.
:J:
"
.,.
8
Go
'"
w
.,.
CD
~.
o
"
..
Section 3
Paragraphs
1-2
NAVSHIPS 900,853 Installation
and
Initial Adjustments
SECTION
III
INSTALLATION
AND
INITIAL ADJUSTMENTS
1.
UNPACKING.
Each Speaker.Amplifier is shipped
in
completely
moisture·
proof
packing which consists
of
two separate
corrugated cardboard cartons, a moisture·
proof
bag,
desiccant, and
an
outer
wooden box. Care should he
exercised
in
removing
the
unit
from its containers
to
avoid severe jolts which
might
damage the vacuum
tubes installed
in
the unit.
Hooks
or
other
sharp
in·
struments which
might
damage the speaker cone should
not
be used.
2.
INSTALLATION.
This
equipment
is
amenable to either
bulkhead
or
table mounting.
For
bulkhead
mounting,
four
mount-
ing
holes are furnished
in
the back
of
the cabinet.
If
table installation is desired,
four
mounting
holes
may
be
drilled
where
"spotted"
on
the
bottom
of
the
cabinet.
Where
two
or
more units are installed
in
the same
compartment,
it
is
preferred
that
the units be placed
on
the same
bulkhead
and
spaced
in
such a
manner
that
each
unit
covers
an
equal deck area.
NOTE
The
installation
of
the Speaker-Amplifier units
should be limited to enclosed
~paces
offering
some degree
of
protection
from
gun
blast as
this
equipment
is neither
water.proof,
sub-
mergence-proof,
nor
blast.proof.
In
order
to
provide
for
the entrance
of
the
input
and
power
cables, bosses are furnished
on
each side
and
on
top
of
the cabinet in which holes may be drilled to fit
the cables. Side
or
top
entrance should be made ac·
cording
to
the convenience
of
installation.
After
the
input
cable,
containing
the
output
of
from one
to
five
stations from the central radio receiving equipment, has
been introduced
to
the
cabinet, connections should be
made
to
the
input
terminals indicated
in
figure 3·1.
If
the
output
of
the
central radio receiving equipment
incorporates a balanced line, a
jumper
wire should be
placed from terminal #
12
(input
center
tap)
to
termi-
nal
#7
(ground).
Power connection from a 115 V
AC
line cable is then
made
to
terminals
#)
3
and
# )4.
NOTE
This Speaker.Amplifier is designed
to
operate
ONLY
when connected
to
a
II
5 volt 60 cps
single phase AC
power
source.
DO
NOT
con·
nect to a
DC
power
source as the line fuses
(F·JO)
and
F·J02)
will
burn
out
under
these
conditions,
and
damage to
the
power
trans-
former
(T.)04)
may result.
A direct lead
from
a
good
ground
shall be connected
to
terminal #
7,
which serves as the circuit
ground
for
this equipment.
Figure
J-J.
Main Terminal Board Diagram
3·0
Installation
and
Initial Adjustments
NAVSHIPS
900,853 Section 3
Paragraphs
2-3
The
equipment
is
so designed
that
no
additional
bonding,
shielding,
or
grounding
is
required except as
noted
in
the
preceding
paragraph.
No
cables
for
the
required external connections be-
tween this
equipment
and
the
power
line,
ground,
and
the
companion
receiver
or
receivers are furnished, either
in assembled form
or
as
bulk
parts.
The
external cabling
should
he installed in
the
most
convenient
manner
commensurate
with
the least pos-
sible
power
loss
or
voltage
drop
in
the lines,
and
mini-
mum
noise pick.up in
the
input
circuit connections.
3.
INITIAL
ADJUSTMENTS.
Adjust
the
output
of
the
companion radio receiver
or
,eceivers
(Navy
Type
RHO
or
equivalent) so
that
the
input
to
any Speaker·Amplifier will be
within
the
range
of
6 milliwatts (1.9 volts across 600
ohms)
to
2 watts (34.7 volts across 600
ohms)
for
proper
operation
of
the
Speaker·Amplifier.
The
input
selector
on
the
outside
of
the
front
panel is adjusted to select
a total
of
five inputs.
1£
less
than
five
input
circuits
are to be used, the switch stop must be adjusted so
that
the
number
of
switch positions will correspond
with
the
number
of
input
circuits connected
to
the
amplifier.
To
reset the
stop
on
the
input
selector
switch, first, remove
knob
from
the
switch shaft; second,
remove
the
switch
mounting
nut
and
pull
switch from
opening
in
panel
(inside);
third,
turn
the
stop plate
(with
stop
pin
attached)
until
placing stop
pin
in locat-
ing
hole will give
the
number
of
input
positions desired;
and
finally, replace switch
in
panel, secure
with
mount-
ing
nut,
and
replace switch knob.
3-1
Section 4
Paragraphs
1-2
NAVSHIPS
900,853
Operation
SECTION IV
OPERATION
1.
This
Speaker.Amplifier is designed
to
furnish the
rated three watts
of
audio power to the integral loud-
speaker with a power input--to the amplifier
of
6 milli-
watts (1.9 volts across 600
ohms)
to
2 watts (34.7 volts
across 600 ohms). An input
of
less than 6 milliwatts
may result in insufficient sound output, and
an
input
of
more than 2 watts may result in overloading with
objectionable distortion
of
the sound output. (See para-
graph
III·3)
2.
To
operate
the
Speaker-Amplifier
after
complete
installation has been made, move the "OFF-ON" switch
(figure 4-1)
to
the
"ON"
posItIon
and
set the channel
selector switch to the desired station. The volume con-
trol
on
the
right
side
of
the
panel should then be set
to the desired volume which increases with the scale.
Finally, the
tone
control
on
the left
of
the
"OFF-ON"
switch should be set to give the desired tone.
It
will be
noted that the minimum attenuation
of
the high fre-
quency response occurs with the knob in the most clock-
wise position.
It
follows that the attenuation
of
the
high frequency response increases
as
the knob
is
turned
counterclockwise.
n,
<~.
•.••. _
_
t"~"
••
~".'''
""_
.-.-
'"'---:.-=
~
~
.
Figure
4-
J.
Lower
front
Panel
4-0
I~
I~
~-----.---------.----,-
--=--~-----
Operation NAVSHIPS
900,853
Section 4
4-1
Section 5 NAYSHIPS 900,853 Maintenance
5-0
FAILURE REPORTS
A
FAILURE
REPORT
must
be
filled
out
for
the
failure of
any
part
of
the
equipment
whether
caused
by
defective
or
worn
parts,
improper
operation,
or
external influences.
It
should
be
made
on
Failure
Report, form NBS-
383,
which
has
been
designed
to simplify this
requirement.
The
card
must
be
filled
out
and
forwarded
to
BUSHIPS
in
the
franked
envelope
which
is
provided.
Full
instructions
are
to
be
found
on
each
card.
Use
great
care
in filling
the
card
out
to
make
certain
it carries
adequate
infonnation.
For
example,
under
"Circuit
Symbol"
use
the
proper
circuit identification
taken
from
the
schematic
drawings, such
as
T-803, in
the
case
of a transformer,
or
R-207, for a resistor.
Do
not
substitute
brevity
for clarity. Use
the
back
of
the
card
to
completely describe
the
cause
.u
.....
u
.....
H
...
W,,",H'.O"".,~,
~.
of
failure
and
attach
an
extra piece
of
paper
if necessary.
The
purpose
of this
report
is to inform BU-
SHIPS of
the
cause
and
rate
of failures.
The
inrormation
is
used
by
the
Bureau
in
the
design
of
future
equipment
and
in
the
maintenance
of
adequate
supplies to keep
the
present
equip-
ment
going.
The
cards you send in,
together
with
those from
hundreds
of
other
ships, fur-
nish a store
of
information
permitting
the
Bureau
to
keep
in
touch
with
the
performance
of
the
equipment
of
your
ship
and
all
other
ships of
the
Navy.
This
report
is
not
a requisition. You
must
re-
quest
the
replacement
of parts
through
your
Officer-in-Charge in
the
usual
manner.
Make
certain you
have
a
supply
of
Failure
Report
cards
and
envelopes
on
board.
They
may
be
obtained
from
any
Electronics Officer.
.........
>GO
..
,.
............
'.
_
.......
_---
...
-
NAVY
DEPARTMENT
BUREAU
OF
SHIPS
WASHINGTO~!!5.
D.
C
.l
._
19cJd;·lq4~
Sample
Failure
Report
Cards Properly Filled
In
r
Maintenance
NAVSHIPS
900,853
Section 5
Paragraphs
1-3a
SECTION
V
MAINTENANCE
1. OPERATORS
MAINTENANCE.
The
only
maintenance
required
of
the
operator
is:
a.
REPLACING
BURNED·OUT
PILOT
LAMP
(REPLACEABLE
FROM
FRONT
OF
PANEL).
(1)
Unscrew
and
remove
the
red
jewel assembly.
(2)
Remove
the
defective
pilot
lamp.
(3)
Insert
a
new
Mazda
51
or
equivalent
pilot
lamp.
(4)
Replace jewel assembly.
h.
REPLACING
DEFECTIVE
VACUUM
TUBE.
(1)
Throw
"ON·OFF"
switch
to
"OFF"
position.
(2)
Open
the amplifier case.
(3)
Remove
the
defective tube.
Remove
tuhe
with
a
straight,
upward
pull.
DO
NOT
move tube from side
to
side as this may result
in
the base key
breaking
off
and
remaining
in
the socket.
(4)
Replace
with
proper
type tube.
(5)
Close the amplifier case.
IN
ORDER
TO
OBTAIN
FULL
TUBE
LIFE
AND
PROPER
OPERATION,
DO
NOT
USE
TUBES
OF
OTHER
TYPES
THAN
THOSE
HEREIN
SPECIFIED.
ALL
TUBES
FURNISHED
AS
INITIAL
SUPPLY
OR
SPARES
SHALL
BE
USED
PRIOR
TO
EMPLOY·
MENT
OF
TUBES
FROM
GENERAL
STOCK.
e.
REPLACING
BLOWN
FUSES.-DO
NOT
RE·
PLACE
UNTIL
THE
DEFECT
CAUSING
THE
FUSE
TO
BLOW
HAS
BEEN
ISOLATED
AND
COR·
RECTED.
(I)
Throw
"ON·OFF"
switch to
"OFF"
position.
(2)
Open
the amplifier case.
(3)
Remove
blown
fuse
from
fuse
hoard
located
on
back
panel
of
amplifier
case.
CAUTION
Equipment
"On-Off"
switch does
not
remove
the
power
from
the fuses.
The
fuse clips
at
the
top
of
the fuse
board
have a
potential
difference
of
115 volts
AC
between
them
at
all times. Use due
precaution
in
removing
the defective fuse.
(4)
Insert
new fuse
Type
3AG,
1.0 ampere.
(5)
Close
the
amplifier case.
2.
PREVENTIVE
MAINTENANCE.
Operator
shall be
guided
by
Chapter
67
of
the
"Bureau
of
Ships
Manual".
Vacuum
tubes
(V·IOI,
V·102, V·103,
and
V·104)
sh.ll
be checked
on
a
standard
tube checker
after
every 250
hours
of
operation
or
every three
months,
whichever
comes first. Defective tubes shall be replaced. immediately
for
most
efficient
operation
(See
paragraph
Ib
of
Section
5).
The
dry
electrolytic capacitors (C-101
and
C-102) are
used as cathode
by-pa~s
capacitors,
and,
under
normal
conditions
of
operation,
have sufficient safety factor to
insure a life expectancy equal to
that
of
the entire equip-
ment.
The
balance
of
the
components
in
this
equipment
are
not
subject to
deterioration
due
to
operation,
and
need
to
be checked
only
in
case
of
equipment
failure (See par-
agraph
3
of
Section 5
on
"Corrective
Maintenance").
3.
CORRECTIVE
MAINTENANCE.
If
any
major
repairs
or
replacements become neces-
sary, it is recommended
that
such repairs
or
replace-
ments
be
made
in
a well
equipped
shop
where the
proper
tools,
measuring
equipment,
and
personnel are
available.
Before
making
any repairs
or
adjustments
in
the
Speaker-Amplifier,
it
should
be definitely ascertained
that
the
difficulty
being
experienced is
not
the result
of
external
or
deteriorating
influences such as
worn
out
tubes,
improper
operating
voltages,
blown
fuses,
exterior
noises, etc.
Over-
and
under-chassis views (figures 5-1, 5-2,
and
5-3)
show
the
location
of
tubes
and
other
parts
of
the
Speaker·Amplifier.
Figure 5-4 shows a typical
audio
frequency response
curve,
and
may
be used
in
checking the
over~all
perform-
ance
of
the amplifier if
the
required
audio
oscillator
and
output
meter
is available.
Following
is a suggested systematic procedure
of
"trouble-shooting"
malfunctions
of
the
equipment:
a.
If
the
equipment
does
not
operate
when
the
switch
is
moved
to
the
"ON"
position:
(I)
Check the
power
supply
to
make sure
that
the
source is
11
5
volt
AC
60 cps.
(2)
Check
the
fuses.
(3)
Check
the
circuit
continuity
through
the cables.
(see figures 3·1
and
5·5).
5-1
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