GENERAL
RECORD CHANNEL
REPRODUCE CHANNEL
BIAS
ELECTRONIC ALIGNMENT
ALIGNMENT
VI.
PARTS
5-1
AND
ERASE
AND
LIST
6-1,
5-1
5-1
5-1
OSCILLATOR
TEST
5-1
5-2
EQUIPMENT REQUIREMENTS
List of Illustrations
Fig.
No. Caption
FRONTISPIECE
2-1
TAPE MAGNETIZATION
2-2
RECORDING HEAD
2-3
MAGNETIZATION CURVE
2-4
OUTPUT
2- 5 ACHIEVING FLAT
3- 1
SPACE
3- 2 TAPE THREADING AND NOMENCLATURE
4-
1 MECHANICAL OPERATION SIMPLIFIED
4-2
ROUTINE LUBRICATION
4-3
TAPE TENSION MEASUREMENTS
4- 4
TAPE TRANSPORT EXPLODED VIEW
5- 1 REPRODUCE AMPLIFIER
5-2
RECORD AMPLIFIER
5-3
SCHEMATIC DIAGRAM
VS.
FREQUENCY
REQUIREMENTS
Page
2-1
2-2
2-3
2-4
RESPONSE
2-5
3-2
4-3
4-5
RESPONSE
RESPONSE
5-4
5-7
5-2
3-3
4-2
Page 4
I. Description & Specifications
STEAM POWERED RADIO.COM
The AMPEX Model
recorder designed
tion
of
these versions:
Power Input
Tape Speed
117
IY2
Head Assembly full
for
601 is a
lightweight, portable, magnetic tape GENERAL
professional use,
volts,
50 or 60
per second
or 3 -M
seconds
(ips)
or
half track
and is
(cps)
inches
available
cycles
per
in any
combina-
An accessory transformer (Catalog No. 17331-1) featuring convenient,
quick plug-in change from high
available
horizontal
for use
with this model.
or
vertical position.
saddle-tan Samsonite case,
to low
The
It is
packaged
or is
obtainable uncased
impedance microphone input
machine
can be
in a
operated
durable, luggage-type,
for
custom instal-
in the
is
lation.
TABLE
1-1
EQUIPMENT SUPPLIED
UNIT (ips) WIDTH (CPS) CAT.
Complete
Equipment
(in carrying 7-1/2 Half 60 7948-1 16-1/2x13-3/4x8.
Case) 7-1/2 Full 60 7948-2 16-1/2x13-3/4x8.
Tape Transport 7-1/2
Electronic
Assembly 3-3/4 17416-101 6-1/8x12-1/2x5.
Power Cord
Mating Connector, Microphone Input
Miniature Phone Plug, Line Input
Mating Plug, Output
TAPE SPEED TRACK LINE FREQ AMPEX DIMENSIONS
7-1/2 Half 50 7948-5 16-1/2x13-3/4x8.
7-1/2 Full 50 7948-6 16-1/2x13-3/4x8.
3-3/4 Half 60 7948-101 16-1/2x13-3/4x8.
3-3/4 Full 60 7948-102 16-1/2x13-3/4x8.
3-3/4 Half 50 7948-105 16-1/2x13-3/4x8.
3-3/4 Full 50 7958-106 16-1/2x13-3/4x8.
Half 60 6200-14 9-5/16x12-1/2x5.
7-1/2 Full 60 6200-10 9-5/16x12-1/2x5.
7-1/2 Half 50 6200-15 9-5/16x12-1/2x5.
7-1/2 Full 50 6200-11 9-5/16x12-1/2x5.
3-3/4 Half 60 6200-121 9-5/16x12-1/2x5.
3-3/4 Full 60 6200-122 9-5/16x12-1/2x5.
3-3/4 Half 50 6200-123 9-5/16x12-1/2x5.
3-3/4 Full 50 6200-124 9-5/16x12-1/2x5.
7-1/2
NO.
17416-1 6-1/8x12-1/2x5.
CS-5
PL-33P
PL-450
PL-445
(Ins.)
96.
Notes:
1.
All
mating connectors are supplied without wiring
for diversified installation.
2.
Hardware kits
are
available
to
facilitate maintenance.
as a
convenience
(See
Sec-
Page 5
SPECIFICATIONS
STEAM POWERED RADIO.COM
Tape
Width
Reel
Size
Tape
Speed
Playing
Time
Reproduce
Accuracy
Flutter
Starting
Stopping
Fast
Rewind
Frequency
Signal-to-Noise
Record
Reproduce
Operating
Timing
and Wow
Time
Time
Forward
Time
Response
Inputs
Output
Controls
Time
Ratio
VA inch.
7 inch, RETMA reel (maximum).
IV2 ips,
IVj ips, half track.
3M ips,
.3M ips, half track.
Full
IV2 ips, 1200
Half
71/2 ips, 1200
±0.2%, or an
a 30-rninute recording.
71/2 ips—Below 0.17% rms.
The
fifth
Less
90
90
71/2
10,000
cps.
3M
Full
ord
point
measured while using a 400 cps tone; and
peak
produce amplifier noise.
Half
MICROPHONE: Accommodates any high
impedance microphone, and can be quickly
converted for a low impedance microphone
with
alog No.
LINE:
level.
1.23 volts rms into 600 ohms at program level.
PLAY—REC: The play mode is
placing
The record mode can be
pressing the
the
The
remains lighted while the machine is in the
record mode.
REWIND—FAST FWD: This
switch
PLAY—REC switch.
lull
track.
full
track.
Track—32
Track—64
ips—Below 0.3% rms.
tape
second
than one
seconds
seconds
ips—40
cps
ips—±2 db 50 to
Track—over 55 db below
level.
of 3% total rms iiarmonic distortion,
record level includes
Track—50
the
0.5
the switch in PLAY position.
selector
safety
is mechanically interlocked
minutes
feet.
minutes
feet.
accuracy
attains
full
in either the play or record mode.
second.
for
full
for
full
to
15,000
down
no more than 4 db at
Peak
record level is defined as the
db below
plug-in
accessory
17331-1).
volt
required for normal program
safety
switch is placed in REC position.
button, a flat topped neon lamp,
witii
7 inch reel,
with
7 inch reel,
of ±3.6
speed
1200 foot reel.
1200 foot reel.
cps ±2 db 50 to
7500
bias,
selected
button at the
seconds
in
less
cps.
peak
erase
peak
record level.
transformer (Cat-
selected
only by de-
same
selector
than one-
15,000
and re-
with
in
rec-
by
time
the
Reproduce
Operating
Miscellaneous
Monitoring
Head
Power
Accessories
Output
Controls
Assembly
Requirements
MIC
REC LEVEL, and LINE REC LEVEL
are
separate
The MONITOR
for
monitoring as described in the
paragraphs; but it functions
ating
ITOR
position
signal to the OUTPUT.
A
toggle ON—OFF switch, located on the
control
placed in the ON position, this toggle switch
will
cause
will
not move
switches is turned
The MICROPHONE
connector, is conveniently located on the control
microphone converting audio sound waves to electric current.
capable
field,
field
of being magnetized is placed in the
the molecules of the material
field.
Any of several methods can be
field,
but of most interest in magnetic
produced when a current
from
a transducer—for example, a
flows
will
through a
proximity
be oriented
coil
of
Magnetic
Tape
Magnetic recording
tape
consists
of
finely
ticles deposited upon a plastic backing. This
magnetic
iron
and magnitude of the
field
in
which
the magnetizing force is alternating, and the
oxide particles are aligned according to the
field
(See Fig. 2-1).
divided
tape
iron-oxide
is moved through a
instantaneous
par-
direction
Fig.
2-1.
Tape
Magnetization
2-1
Page 7
Magnetic
STEAM POWERED RADIO.COM
Head The magnetic
over
which
the recording
shaped
electromagnet (See Fig. 2-2). It
of
highly
uity
magnet.
permeable material inserted in a
in the
ring
field
is produced in the gap of a recording head,
tape
passes.
forms the gap, and the
The recording head is a
consists
ring
of an incomplete
coil
of
wire.
The discontin-
is the core of the electro-
ring-
ring
Magnetization
GAP
Fig.
2-2. Recording Head
Curve The magnetization curve of the
Bias
While
medium
near the
ed on the
to
production.
high-frequency
signal being recorded. The frequency of this
to
beating between the
ization
shown
the
the
ization,
flux
After
which
on
which
of
is similar to that shown as the heavy
origin,
the curve is extremely non-linear, and the signal record-
tape
would
not be
directly
the head. This
be five times the upper frequency
the
characteristics of the
in Fig. 2-3,
tape
leaves
bias
is reduced to zero, and the
known
at the time the
the recording
is proportional in magnitude and
it. If the
is similar in construction to the record head—the magnetic
the moving
would
result in a
This
distortion
constant amplitude
bias
tape
is in the recording gap, the
known
the gap, the influence of the magnetic
as REMANENT
tape
tape
is then moved
tape
will
is greatly reduced by the application of a
and harmonics of the recorded signal.
iron
as the
leaves
the gap.
process,
there
induce a voltage in the
TAPE
e
iron
oxide
utilized
line
proportional to the signal applied
high
degree
bias
signal
which
bias
limit
of the recorder to prevent
bias
oxide to
MINOR
INDUCTION,
past
follow
HYSTERESIS
tape
assumes
exists
on the
direction
the gap of a reproduce head—
as the recording
in Fig. 2-3. At points
of
distortion
is mixed
is generally
causes
the magnet-
the
dashed
a permanent magnet-
determined by the gap
tape a flux
to the signal recorded
coil
of the reproduce
line
LOOPS. As
field
created by
upon re-
with
the
selected
loops
pattern
flux
Fig.
2-3. Magnetization Curve
head. This induced voltage is proportional to the number of turns of Induced Voltage
wire
on the head, and the rate of
lowing
equation:
Where E is the
N
is the
d0tlt
is the
It
is desirable that the gap in the reproduce head be as small as
possible,
the
ever, as the gap is
is a practical
quate
so that the gap
signal on the
limit
signal-to-noise
will
tape
at the highest frequency to be reproduced.
made
smaller the induced voltage
in
decreasing
ratio.
change
E =
N(d0at)
induced
number
rate
intercept
the gap and
of
flux,
voltage
of
turns
of
change
less
expressed
in the fol- in Head
of wire
of
flux
than one wave length of
How-
decreases,
still
maintaining an
so there
ade-
2-2
Page 8
Induced Voltage
STEAM POWERED RADIO.COM
in Head
The voltage induced
across
rhe head is computed by the
following
equation;
E = B V sin
Where E is the induced
B
is the maximum flux density of the recording
m
voltage
TTcj/
/x
material
V
is the velocity of the
w
is the gap width
X is the wavelength of the signal on the
From
this expression it can be
increases
creases
assumed to be constant, the
portional
large compared to the gap
characteristic such as shown in curve A of Fig. 2-4. The voltage
not
rial
dimensions as the reproduce head gap, rhe actual
B of Fig. 2-4.
directly as the velocity
(frequency
increases).
If rhe tape velocity and gap
output
to the frequency, as long as the wave length on the tape is
width.
continue to rise
increase,
indefinitely.
and as the wave-length on the tape approaches the
tape
over
seen
that the voltage
increases
voltage
and as the wave-length de-
from
the head is directly
This results in an
As electrical
losses
output
the head
across
output
vs. frequency
in the
core
resembles
tape.
the coil
width
are
pro-
does
mate-
same
curve
In
order to provide an overall frequency
Fig.
2-5) an equalization circuit consisting of a
capacitance
fier.
Fig.
is inserted in one of the early
This equalizer has a high-frequency droop characteristic (curve B,
2-5)
which
is the inverse of the reproduce head characteristic
(curve A, Fig. 2-5). In order to extend the high-frequency
additional
equalization is included in the record amplifier in the
response
stages
of the reproduce
that is
series
flat
resistance
ampli-
response,
(see
and
form
of a high-frequency boost circuit, designed to compensate for the droop
in
reproduce head characteristics
and
recording
losses.
caused
by head
core
losses,
gap
losses
Frequency Response
2-4
OUTPUT
(db)
+ 25
+ 20
+ 15
+10
-10
-15
-20
-25
+5
0
-5
10 100 1000
FREQUENCY
Vig. 2-4. Output vs.
1
J^__.
1
1
1
1
1-
+
1
Frequency
1
(
A !/
— —
t
lOKC
1 B t 1 B
Fig.
2-5. Achieving Flat
Response
2-5
Page 9
III.
STEAM POWERED RADIO.COM
Installation and Operation
This machine
position.
and
connecting
For studio installations,
which
permits mounting
The power requirements
61 watts. A name plate
ture
for
line
frequency.
The line
Any
unit
nal
of at
tape recorders.
The recorder
vision
for
diately
To make this conversion, remove
electronics assembly.
A.
B.
C.
can be
In the
OUTPUT,
input
connected
least
changes
High
Low
30 ohm to 50
carrying
the
required
LINE
is an
to the
0.5
volt
is
wired
internal mounting
the
machine
The
Impedance- -a dummy
Impedance — remove
operated
case,
installation
cables
an
adaptor (Catalog
in a
standard 19-inch relay rack.
are 117
on the
INPUT
unbalanced
LINE
when recording
for a
high
of an
for use
panel
matic diagram (Fig.
into
eration.
sory transformer AMPEX catalog number
173.51-1
gram
for
to
250
ohm — Install transformer
the
ging
removing
on
in
either
the
horizontal
consists
(See
"Connector"
volt
a-c, 50 or 60 cps, 0.52
bottom
and
of the case
and 117 v. a-c
bridging
INPUT connector should deliver a sig-
from
consolettes, mixers
impedance microphone,
accessory
with
low
the
four
screws
assembly
plug
socket
J106S
the
dummy
(shown
Fig. 5.3) is
impedance
ohms.
schematic
the
the
in the
diagram
transformer
the
jumper
schematic.
only
No. 9684-1) is
adjacent
indicates
input
of 100,000
plug-in
J107P
transformer imme-
impedance microphones.
on the
can
then
shown
5..5)
for
high
plug
as T103 on
then plugged
range
T103 as
(Fig. 5.3) by
into
as
or
vertical
of
making
in
this section).
available
ampere,
to the
the
or
but
panel
be
removed.
on the
must
be
plugged
impedance
J107P.
socket
shown
Acces-
schematic
into
of 150
shown
J106,
in
up
aper-
proper
ohms.
other
pro-
of the
sche-
op-
dia-
J106S
ohms
on
plug-
and
Note
GENERAL
POWER
LINE INPUT
MICROPHONE
INPUT
7
The output
ohms
input
into a high
tor with
pedance
plug
anced
MONITOR
a 600 ohm
circuit. A three circuit OUTPUT
can be
line.
of the
machine should
impedance.
impedance
used,
If an
jack only.
In a
situation wherein
line,
physically terminate
resistor
and
bridge this resistor
and
will
work;
but it
AMPEX amplifier loudspeaker
be
connected
plug
automatically
to a
unit
having
the
recorder
the
OUTPUT
with
is
supplied. A two circuit
is
used
the
makes
plug
will
connec-
high
an
it
into
unbal-
600
work
im-
the
REPRODUCE
OUTPUT
Page 10
INTERCONNECTING
STEAM POWERED RADIO.COM
CONNECTORS
STUDIO
INSTALLATION
•' to a
Regardless
of application
observe
the requirements under "Line
and "Reproduce Output" when interconnecting the machine
other
piece
of equipment.
A power
LINE
plied
Shielded, low-capacity
and output
necting units in audio
cable
and matching plugs for the MICROPHONE
INPUT
with
(J102S),
the equipment.
cables.
and OUTPUT
cable
Make such
systems.
(J104S)
connectors
is recommended for making up
cables
as short as possible for intercon-
Refer
to the
schematic
5.3), to determine correct pin connection for all plugs.
The reproduce head
pickup.
ening this
Cable
frequency
port
ened
will
loss.
no more than one foot apart. If the reproduce head
for
greater
be affected. In the event an installation absolutely demands length-
cable,
the addition of an outer shield.
minimum
Space
requirements for custom installation are given in the
panying
side of the
PUT
illustration (Fig. 3-1).
electronics
connectors.
panel mounted at
vide
ready accessibility.
cable
is double shielded, insuring against r-f
capacity and length
In general, mount the electronic
have
been
minimized to avoid high
assembly
separation of the components, high frequency
a very low capacity type
High
if the
cable
length
exceeds
Allow
chassis
for
easy
If desired,
some
these
connectors
more convenient point in the installation to pro-
(RG-62/U)
frequency
three
sufficient
access
losses
feet.
clearance
to LINE INPUT and OUT-
can be brought to a patch
Input"
with
any
(JIOIS),
are sup-
input
diagram (Fig.
and
tape
trans-
cable
is length-
response
is indicated, plus
cannot be kept
accom-
at the
right
The
tape
threading path described below is the
of operation; but special attention is called to the
half track
Step
1:
heads.
Place
a reel of
tape
on the left-hand turntable, and an empty
reel on the right-hand turntable, making certain that the pins
around
the
base
of
each
spindle
engage
corresponding
the reel hubs.
Step
2:
Press
Step
3: Thread the
Step
4: Anchor the
a reel hold-down knob in
tape
as indicated in the frontispiece. Make
the oxide or
but a full
dull
surface
tape
in the slot on the empty reel hub if desired,
tape
turn
place
on
is against the
heads.
counterclockwise around the reel hub is
usually sufficient.
SUPPLY
HOLD-DOWN
REEL
TAKEUP
same
notes
each
for all
dealing
spindle.
modes
with
slots
sure
TAPE
THREADING
on
,
3-2
Fig.
3-1.
Space
Requirements
MICROPHONL
MnNllLP
RECORD
SELECTOR
LEVEL LEVEL
Fig.
3-2.
Tape
LINE
RECORD
Threading
MICROPHONE
INPUT
and
Nomenclature
NOTE
Because
record or reproduce only half the
the
half to be recorded is farthest
transport
been
cording
must be turned over and the
machines
using half track
tape
tape
supply must be so oriented that the
from
surface.
wound onto the take-up reel
run, for
After the entire
instance,
the take-up reel
from
second
heads
width,
the
tape
tape
has
a re-
half recorded—or indentified for a later run. For
example:
Page 11
RECORDING Step 1: Thread a tape as directed under "Tape Threading."
STEAM POWERED RADIO.COM
HALF TRACK Step 2: Set the machine as indicated in "Recording," immediately
lowing.
Step
3: The entire tape must be reeled onto the take-up reel, regardless
of
whether or not the recording is completed. FAST—FWD
can be used if program material
Step
4: Remove the take-up reel
Step
5: Remove the turntable reel
Step
6:
Place
the take-up reel on the turntable side.
Reversing the take-up reel after a recording run,
only
position for proper threading
orients
the
still
unrecorded half of the tape so that it is farthest
tape transport. If the tape had been
have
erased
the previous recording.
does
not use the entire tape.
from
the machine and
which
is now free of tape.
places
the tape in the
from
the turntable side; and also
rewound,
the second run
turn
it over.
from
would
fol-
the
To stop recording,
by
a dot.
Step
1: Thread a previously recorded tape on the machine. REPRODUCING
Step
2:
Place
Step
3:
Place
Step
4:
Place
return
the PLAY—REC control to neutral, marked
the ON—OFF toggle in the ON position.
the PLAY—REC control in the PLAY position.
the MONITOR
SELECTOR
switch in the TAPE posi-
RECORDING
tion.
Step
5:
Adjust
the reproduce level
program
source.
If
there is no
switch
position. When the machine is in the play mode,
the MONITOR
position.
plugged
OUTPUT can be monitored
into
through
output,
check
SELECTOR
the jack on the
the volume control of the
the MONITOR
SELECTOR
switch must be in the TAPE
with
the headphones
front
panel.
REPRODUCING
UAic
TDArir
HALF
TRACK • r i r i c
RECORDING Previously recorded
Refer
reproduce correctly
to the
steps
in "Reproduce,"
only
if oriented so that the half of the tape desired
IS
farthest
In
reproduce mode, after the entire tape has been reeled onto the take-up
reel,
are made,
first
for
the finest recording, it is recommended that the
Step
from
the tape transport surface.
reverse the reel and place it on the turntable side.
tapes
are
pass
eliminating
over the
the need for an erasure run
erase
head whenever the machine is recording; but
1: Connect the program source equipment (microphone, mixers,
etc.) to the appropriate
Step
2:
Place
the MONITOR
following.
erased
automatically as new recordings
input.
SELECTOR
function.
Step
3:
Step
4:
Place
Adjust
the ON-OFF toggle in the ON position.
either the MIC REC LEVEL or the
control,
depending on whether the MICROPHONE
the
LINE
INPUT is being used, so that on the most intense
volume
peaks of the program to be recorded, the v-u meter
needle swings to approximately zero on the v-u
unnecessary to start the tape
gram
level. If
only
one
motion
input
is being used,
REC LEVEL to zero.
Step
5:
Place
the PLAY-REC control in the REC position by depress-
ing
the safety
selected. The transparent plastic
button
at the
same
time the record position is
button
chine is in the record mode. This record safety feature prevents
accidental erasure of previously recorded tapes. When
ing
to the PLAY or the neutral position at the dot, the safety
button
is not used.
While
recording, a continuous comparison of the incoming program
and
the reproduction on the tape can be effected by
TOR
SELECTOR
switch back and
forth
between the INPUT and
TAPE positions and observing the v-u meter, or using headphones.
The half track tape
because
tapes
be tank erased.
the
will
tapes
switch on the INPUT
LINE
REC LEVEL
input
or
scale.
It is
in order to set the
turn
glows
while
pro-
the other
the ma-
return-
turning
the
MONI-
To
rewind
FWD
minute
REWIND
decelerate or stop. Thus, cueing and
high
or move tape
forward
rapidly,
place REWIND — FAST
switch in the position desired. The tape moves at 800 feet per
in either direction, and can be shuttled back and
and FAST FWD positions
speed
with
no danger of tape breakage.
without
editing
waiting
can be accomplished at
forth
between
for the tape to
The REWIND—FAST FWD and PLAY-REC controls are mechanically
interlocked, making impossible the switching of either control
unless the other is in neutral. This safety feature guards against tape
breakage
either of the
which
high
would
occur if the machine were switched directly
speed modes to PLAY or REC position.
from
CAUTION
Always
return
REWIND—FAST EWD control to neutral
position,
PLAY
while
To
erase
a previously recorded tape when no new reproduction is de-
sired,
turn
both of the REC LEVEL controls to zero and run the tape
in
the record mode.
Because
governed
sources
microphone and line recording channels are independent,
by its own level control, simultaneous recording
can be made
and
wait
til tape motion stops before switching to
or REC. Placing selector controls on PLAY or REC
tape is in
motion
will
cause
stretched or broken tape.
each
from
two
without
an external mixer.
For example, singing, voice announcements or instrumental accompaniment
solette or other tape recorder. To effect
equipment
MICROPHONE
LEVEL
can be dubbed
to the
LINE
connector.
and
LINE
REC LEVEL controls for desired balance between
into
a program being recorded
this,
connect the program source
from
a con-
INPUT connector and a microphone to the
Adjust
both the MICROPHONE REC
the two programs.
REWIND AND
FAST FORWARD
ERASE
MIXING
3-4
3-5
Page 12
SYNTHETIC
STEAM POWERED RADIO.COM
REVERBERATION
Special
effects, similar
chamber
Connect a microphone and
the
MONITOR
verberation
away,
value chosen
set too
will
lower
can be
OUTPUT connector
SELECTOR
decay
can be
swing
setting.
varied
will
high,
continuous oscillation
to
maximum and remain there.
to
those
created easily.
set
to the
switch
rate,
which
is
with
the LINE
depend
entirely
obtained through
the program level
LINE INPUT connector,
to
TAPE, and start recording. The
the time required
REC
LEVEL
on
the effect desired.
will
result, and the v-u meter needle
If
the use of an
as
usual; then connect
for the
control.
If
this
happens,
turn
echo
The
the
adjust
echo
the
re-
to die
Control
control
to a
is
IV.
Tape
The
tape
transport mechanism incorporates a single-speed
motor
and a system
and
the
turntables. Three
and
EAST
FORWARD)
the
top panel
trol
is
The bracketed numbers in this section refer
Fig.
4-4, and in
facility
be opened
Power
the
front
The
capstan
nylon
belt
capstan
stan
flywheel
brake rollers
rewind
machine
Since
the
dition,
the
PLAY switch
of
marked
in
is
clutches
the
by a
following
fully
applied
panel
(42)
(68)
flywheel. A second
drives
(2) are
is
in standby
capstan
tape
Transport
of
pulleys, belts, and clutches
modes
of
tape
are
determined
the
tape
transport. (The neutral position for
dot.)
the parts
for
to
of
the electronic
which
(16 and
is
will
is
list
at the end of
the discussion below,
ready reference.
the drivemotor
begins
to
runs between
belt
the
play takeup pulley
engaged
31). Both turntables
condition.
in
motion
accelerate
operated, thus producing a wow-free start.
(63)
when the POWER switch
assembly
rotate immediately, being
(69)
against
when the machine
to
full
is
the
running
the rubber-tired
play
Assembly
synchronous
to
drive the
motion
by
it is
speed
(PLAY,
two controls located
to
parts shown
this manual.
suggested
turned
motor pulley
in a
(40). The
are
is
almost instantly when
For
that Fig.
to
the ON position.
driven
(61) and the
groove
shock
fast
forward
motionless,
in the standby con-
REWIND,
in
in
GENERAL
capstan
on
each
con-
Fig. 4-1,
greatest
4-4
on STANDBY
OPERATIC
by a
the
cap-
relief
and
and the
3-6
When
the
PLAY
control
quence
occurs:
1) The play takeup pulley
the
play takeup
2)
The
shock
leased
from
3)
The
capstan
the
tape,
turntable)
gins
to
rotate.
the
machine
tape
is
clamped
tables
are
table,
as
its
fed
to it by the
supply turntable.
4) The shock
gaged
against
between the
in
this
slippage,
brake
(37)
quired
holdback tension.
clutch
relief
brake
the
fast
forward
idler
(79)
pulling
it
from
and
feeding
It is
especially important
is
operating normally in the play mode,
against
effectively isolated
name
implies,
capstan.
relief
brake
the
rewind
clutch
and
and the
operating
is
energized
(40)
(19).
roller
clutch
engages
the
tape
it to the
the
capstan
does
It
does
roller
clutch
disc
assembly
friction
on the
the
following
and belt
(2) on the
from
(2) on
(69) are
tire
(16).
the
capstan
supply turntable (i.e. the
takeup turntable,
by
the
each
nothing
bakelite
more than take
not
pull
the
tire
(31), and
(30). The
produced
drum
brought
play takeup
(42),
to
understand that when
capstan
other.
The
the
tape
rewind
friction
by
the
(35)
mechanical
to
side
which
which
now
in
which
idler,
the
takeup
up
the
from
the
side
remains
slippage
produced
rewind
holdback
provide the
se- PLAY MODE
bear
on
is re-
drives
rewind
be-
the
turn-
turn-
tape
tape
en-
occurs
re-
4-1
Page 13
The
STEAM POWERED RADIO.COM
REWIND-FAST
the
PLAY
control
WARD
control
Both
1)
2)
3)
When
FORWARD:
1)
2)
3)
shock
The
rewind
and the
driven.
Holdback
takeup assembly as
Both
The rubber-tired fast
the motor
Holdback tension is produced by the holdback brake (37) on the
rewind
rewind
tension is provided by the holdback brake (25) on the
drive mechanism is particularly important. The recommended
agent
for cleaning Ampex Head
0.1% Aerosol. This
No.
FP-7.)
cloth
periodically
from
To clean any head
on a swab-stick and moisten
to remove all
the tape. Clean all parts
agent
lintless cloth moistened
tape
tape
gradually
cause
Assemblies
transport mechanism
drive mechanism is required for con-
tape
manufacturers lubricate their
form
a coating on the head
loss
of positive drive at the
assembly
is a mixture of Xylene and
consists
assembly
capstan.
and all parts of
is available in 2 02. bottles. (Ampex Catalog
assembly
dirt
and oxide which may
except
with
denatured alcohol.
simply
with
this mixture.
the head
wind
a clean, lintless
Swab
have
assembly
the
heads
accumulated
with
a clean,
pri-
CAUTION
Do not use any other solvents as there are
adhesive
used to hold the head laminations together.
The recommended standard lubricant for the four
quire
periodic lubrication (motor and
This lubricant is available
from
AMPEX as
some
capstan)
Stock
which may
places
damage
the
which re-
is Caloil No. OC-11.
No. 70-9 (V2 oz.
oiler) or FP-5 (4 02.)
NOTE
The proper lubricant is available
(1/2
oz. oiler) or PP-5 (4 oz.).
from
AMPEX as
Stock
No. 70-9
The upper and lower bearings of the drive motor should be lubricated
after every 500 hours of operation. The upper oil hole of the motor is
accessible
to
the left of the takeup turntable. For
cated
the
through a hole in the
tape
transport grille slightly
access
in the side of the motor end bell, remove the
case
(See Fig. 4-2).
above
and
to the lower oil hole, lo-
tape
transport
from
Four or five drops of one of the recommended lubricants is sufficient.
Care
should be taken to avoid over-oiling or spills. Any such
should
be wiped away
The
capstan
drive
first
be removed (See Fig. 4-2).
Remove
not to
over the
it
removed to
may require
motor. For
the hairpin retainer and
lose
the
washers
capstan
expose
of the recommended lubricants as the bearing
any
excess,
and
with
solvent.
oiling
about
once
for every four oilings of the
access
to the upper bearing, the
associated
Remove
lift
with
the rubber cap on the idler.
the idler off its shaft, taking
it. The aluminum plug-bottom
capstan
shaft may now be pried off and the felt washer beneath
the upper
capstan
bearing. Use as much of one
will
accept,
reassemble.
excess
idler must
care
wipe away
CAU7I0N
Do not oil the felt washer which
to
keep
oil
from
For
working
access
to the lower bearing, remove the
its way up the
serves
only as a dust protector and
capstan.
tape
transport
from
the
case.
The oil hole is located in the bearing housing as shown in Fig. 4-2.
Use
exactly
four
drops
of
oil—no
Do not oil any other parts of the
bearings and moving parts are lubricated for
It
may be said in general, that most of the difficulties that
be encountered in the Model 601
traceable
surfaces,
gradual
over a
to contamination of belts, pulleys, bearings, and other
whether due to
accumulation of
reasonable
carelessness
dirt
length of time. Correction of
more.
tape
transport mechanism. All other
life.
will
tape
transport mechanism
in routine lubrication, or to the
and other foreign material to be
these
difficulties
normally
will
be
friction
expected
will
usually be a matter of careful disas.sembly and cleaning, rather than readjustment of the mechanism. The normal torques (and
tension) in this mechanism are, in fact, fixed
within
fications, and are not adjustable. The measurement of
frequently provide a rapid
means
for isolating the
source
hence,
tape
strict design speci-
these
torques
will
of mechanical
troubles.
Z"W—SEE
NOTE
I I
HOLDBACK
5 3/4- B
2-3
1/2
3/4-1
OZTIN,
1/4 OZ-IN
Tape
FAST
FOHWARD
Tension
5-7 OZ.- IH.
TAKEUP
5-7 02.- IN.
THAN
2 INCHES,
OZ.—IN.
Measurements
3/4
OZ,-IN.
NOTES:
1.
IF REEL HUB DIAMETER IS LARGER OR SMALLER
SPRING SCALE BEADING BY HUB RADIUS TO OBTAIN
2.
PULL SCALE WITH STEADY MOTION WHEN MEASURING HOLDBACK rENStONS.
ALLOW SCALE TO MOVE IN TOWARD REEL WHEN MEASURtNS TAKEOP TENSIONS.
TAKE
ALL READINGS WHILE SCALE IS IN MOTION.
Fig.
4-3.
READING
HOLOaACK
V4-[ 1/4
OZ.-IPt.
MUUTIPLY
,
Mechanical
Troubleshooting
4-4
4-5
Page 15
Torques
STEAM POWERED RADIO.COM
and The measurement of torques on the
Tape Tension
equipment:
1) A light-movement
Weight
Scale
spring
Co., Columbus, Ohio.
Model
601 requires the
scale
(e.g. Post-A-Let, 0 to 8 oz,, Exact
2) A measuring hub. A standard RETMA plastic reel may be used. If
the hub diameter is exactly 2 inches, the
directly
in ounce-inches.
up
to 2-inch diameter by
Reels
winding
with
greater than 2-inch hub diameter is used,
reading
by the hub radius to obtain the ounce-inch reading.
3) A piece of
tied
Torques measured on the
table on
string,
approximately 30 inches
at one end.
driven
turntable in any mode, (i.e. the
which
the tape is being wound) are a measure of
sion. Torques measured on the turntable
on sufficient tape. If a reel of
from
spring
smaller hubs can be brought
multiply
long,
which
the
with
the tape is
• in any mode are a measure of holdback tension (See Fig. 4-3).
following
scale
will
spring
a small loop
takeup
pulled
read
scale
turn-
ten-
The
word
"contaminated," as used here, may indicate either the pres-
ence
of oil where it is not wanted, or accumulations of
foreign
matter on pulleys and belt. In either
is recommended as the cleaning agent.
part,
clean any other part
whether
tion.
or not that part shows any immediate evidence of contamina-
Bracketed numbers refer to parts shown in the exploded
the mechanical assembly. Fig. 4-4,
any
necessary
Rewind
apparent
tion
or slippage, and, possibly no
disa.ssembly and reassembly.
and fast
loss
forward
of power in those modes, loose tape
step is to make a quick check of
holdback
below
tensions as described previously. The malfunctions discussed
apply to either mode, the turntables, associated components, and
tape directions being opposite of
with
which
which
malfunctions
rewind
rewind
each
case,
After
cleaning a contaminated
it normally
should serve as a guide for
will
usually be reflected as an
or fast
forward
or fast
other.
dirt
carbon tetrachloride
comes
into
wind,
erratic tape mo-
at all. The
forward
and other
contact
view
of
first
takeup and
Malfunctions
in Play Mode
Malfunctions in
Rewind or Fast
Forward Mode
Takeup
Tension
Holdback Tension
Malfunctions
in Play Mode
Step 1:
Step 2:
Place
the measuring hub on the
Wind
a few turns of
normal
tape
wrap,
and attacli the
driven
turntable.
string
around the hub in the direction of
spring
scale
to the loop at
the end.
Step 3:
Step 1:
Step 2:
Start the machine in the appropriate mode and, as the
,is
wound
on the hub,
„ing the reading
are as
follows:
Fast
Rewind
Play 2 to 3V2
Place
Wind
the measuring hub on the turntable
is
pulled
in the mode in operation.
the
string
and
attach the
Forward 5 to 7
allow
the
scale
while
the
scale
is in
5 to 7
on
fully
in the direction of normal tape
spring
scale.
to move in
motion.
Normal
oz-in.
oz-in.
oz-in.
from
which
Step 3: Start the machine in the oppropriate mode, and
slowly
in the direction in
this
reel,
taking
the reading
tion.
Normal
torques are as
Fast
Forward ->4 to U/i
Rewind
% to 1(4
Play 5% to 8 4
These
values listed above for both takeup and holdback tensions may
be
close
move
to the lower
up
toward
tlie
limit
when the machine is new, and
upper
limit
which
while
follows:
after the
tape is normally
the
scale
is in steady mo-
oz-in.
oz-in.
oz-in.
first
10 or 12 hours of opera-
with
pull
pulled
will
string
it, tak-
torques
the tape
wrap,
the
scale
from
usually
tion.
Nearly
all malfunctions in the play mode
wow
in
excess
of specifications. A quick check of takeup and holdback
will
be reflected as
flutter
and
tensions, discus.sed in the previous section, may lead directly to the
source of trouble. Possible
the
following
check
list.
causes
of
flutter
and wow are suggested in
Starting,
throwing
troubles
functions
ination
The
alignment
transport
Two
1)
2) To remove the sub-plate (1), a
stopping, and
of tape loops and, in extreme
are usually associated
produced
due to
following
careless
section covers some adjustments, critical
which
shuttling
primarily
oiling
malfunctions
with
low takeup tension of brake
will
cases,
by tape breakage.
be evidenced by the
These
mal-
by tampering or misassembly, or contam-
or accumulation of
dirt.
clearances,
must be maintained in reassembling parts of the tape
mechanism that may have been disassembled for servicing.
general precautions should be observed in any required disassembly:
Always
note the number, type, and location of washers in an assembly very carefully. Should washers, retainers or other small
ware
be lost or damaged in servicing, a kit containing an assortment
of
such hardware (Ampex Catalog No.
your
dealer.
sembly of parts under the top plate casting, remove
elastic stop-nuts that
hold
it, and clevis pin that
(13) to the lower yoke of the rewind/fast
It
is unnecessary to remove the adjustment screws (70 and 71) for
7802)
preliminary
forward
is available
to any further disas-
only
links
the slide lever
actuator (48).
the capstan thrust and the motor thrust. If the settings of
hard-
through
the three
these
and
screws are changed, they must be carefully readjusted as described
in
the
following
screws, being coated
subsections. The thrust discs (65) beneath
with
grease,
will
usually stay in place when
these
the sub-plate is removed. It is advisable, however, to be sure that
they
do not
fall
out. It
will
generally be
found
easiest
to re-install
the sub-plate after servicing, if the PLAY control is energized.
The tape transport incorporates rubber shock mounts on the screws retaining
the motor
mounts
provide automatic centering of the drivemotor and no adjust-
ments are
necessary.
The drivemotor thrust is a hardened steel
mounting
plate to the top plate casting.
ball
(60) against a
These
shock
nylon
Starting,
and Shuttling
Malfunctions
Assembly
Stopping
and
Construction Notes
Drivemotor Thrust
4-6
4-7
Page 16
Drivemotor Thrust
STEAM POWERED RADIO.COM
Turntable Height Turntable height (the
Play Takeup Clutch The play takeup clutch
disc
(65). The
of .010 in. to .015 in. is required, and is obtained as follows:
Step
1:
Step
2: Insert the
Step
3:
Grasp
Step
4: While maintaining a slight downward
Step
5: Tighten the locking nut on the set
turntable (78) to the perforated metal grille) should be .125 in.,
in.
This height is determined by the
betwen the bottom of the turntable pivot (24 or 36) and the hairpin
retainer on the shaft through the pivot. Difficulties in
traced to improper turntable height may be corrected by increasing or
decreasing
(18), and a bakelite clutch (19) which is spring-loaded to the disc.
When the machine is in the play mode, the clutch is driven by the rubber belt (69) on the play takeup pulley (40). Location of the felt-lined
aluminum
tween the end of the oilite bearing (21) which
lite
clutch (19), and the bottom of the aluminum
ance,
which
physical arrangement can be set quite
direa method:
Step
1: Insert a removable .015 in. shim or
Step
2:
Assemble
Step
3: Guide the end of the oilite bushing through the hole in the
Step
4: Holding the
Step
5:
Remove
capstan
Coat
the nylon thrust
and drop it through the threaded hole in the sub-plate (1)
over the
tom
dex finger.
of the
that
the
down
the
screw
point,
play.
rhe number or
disc
thrust
bearing (22) of the takeup turntable pivot (24) and oilite
bushing (21).
and the felt-lined aluminum
turntable shaft (29).
center
down
hub.
spring
num
capstan
set-screw,
on the thrust disc.
the
capstan
set-screw
will
later be applied by the locking
screw
off slowly, and work the
until
an audible click at the
presence
has
been
end play should be in the required range.
is critical—a
cannot
be
washer
the conical spring (20), the bakelite clutch (19),
of the bakelite clutch, and
until
it bottoms
the shim or
will
then
disc, thus creating the required .015 in.
thrust is adjusted by a
disc
liberally
shaft.
and tighten down
flywheel (42) between the thumb and in-
with
the screwdriver (to simulate the
of end play. This
backed
off approximately 14 of a
distance
assembly
measured
that rides on the inner
disc
measured
thickness
plate in
force
of
consists
clearance
directly
firmly
gauge.
the oilite bushing
replacement
these
disc
place,
set-screw
with
capstan
ends
will
usually
screw,
from rhe top
washers.
of a felt-lined aluminum
of .015 in. being required be-
goes
with a gauge
accurately
feeler
race
(18) (in that order) on the
press
on the end of the bushing.
tighten the set
The expansion of the conical
(70). End play
wheel bearing
until
it is felt to bot-
pressure
screw)
of its travel indicates
of lamicoid
disc
by the following in-
on the
start backing
flywheel up and
occur
when the set-
turn.
then
recheck
surface
tape
through the
(18). This
because
gauge
between the
of the lower ball
the aluminum
screw
back
oflf the alumi clearance.
grease
head
pressure
At this
end
of the
±.008
washers
tracking
disc
bake-
clear-
of the
disc
in its
The rubber-tired bakelite rewind (31) and
line
up
with
the
shock
relief brake rollers ( 5) so that the rollers
the
full
width
of the tires. In addition, the rewind clutch (31) should
be aligned for
forward
The
capstan
slipping
stan
speed
use a pre-recorded
of known
Trouble
EXCESSIVE
HOLDBACK
EXCESSIVE
TENSION
DRIVEMOTOR
OE SYNCHRONISM
full-width
clutch (16) for
speed
nylon belt and synchronous motor. No adjustment of the
will
be
accuracy,
Troubleshooting
OR
TENSION
TAKEUP
OUT
contact
full
will
not vary,
necessary.
5000
cycle
and an
ERRATIC
with
width
contact
since
If it is desired to
tape, that has
electronic
TABLE
PLAY
1.
Contaminated rewind clutch
2. Contaminated rewind clutch
3. Rewind clutch spring (32)
1.
2.
3. Takeup clutch spring (20) too
1.
Line voltage below 105 volts a-c.
2.
Excessive
3.
Nylon
4.
Belt
5. Drivemotor thrust misadjusted. See
6. Defective drivemotor starting ca-
7. Dry
8. Defective drivemotor (63).
the rewind idler (7) and the
the
frequency counter.
4-1
Model
Probable
(.30).
(31).
stiff.
This actually indicates tampering
It
is advisable to
rather than to attempt makeshift
readjustment.
Contaminated play takeup clutch
felt
(18).
Oilite
aluminum
mum
See sub-paragraph 8.4 below for
adjustment procedure.
stiff.
trouble
cessive.
low.
tensioning idler (55) drag-
ging.
subparagraph 8.2 below.
pacitor.
bearings
capstan
See lubrication instructions.
fast
forward
with
the motor pulley (61).
capstan
check
been
recorded on a machine
Malfunctions
Cause
or
carelessness
bearing (21) bottoming on
clutch
clearance
play takeup tension. See
above.
drive belt (68) tension ex-
See sub-paragraph 8.1 be-
in drivemotor (63),
(42), or
clutches
is driven by a non-
the
capstan
in
replace
disc
(18).
should be
capstan
must
engage
fast
cap-
speed,
felt
tire
too
reasembly.
the spring
Mini-
.015".
idler (79).
Rewind and
Fast Forward
Clutch Alignment
Capstan Speed
4-8
4-9
Page 17
FLATTED
STEAM POWERED RADIO.COM
CAPSTAN
DEFECTIVE
PROPERLY
NYLON DRIVE
REWIND
DISENGAGING
MOTOR
REELS
RESPECT
Troubleshooting
OR
DENTED
IDLER
TIRE
OR IM-
INSTALLED
BELT
IDLER
(7) NOT 1,
FROM
PULLEY
(61)
MISALIGNED WITH
TO
TAPE GUIDES
REWIND
Trouble
TAKEUP
TENSION
LOW
EXCESSIVE
HOLD-
BACK TENSION
BRAKE
SHOCK
ROLLER
(2) NOT RE-
LEASING
FROM
RELIEF
FAST
FORWARD CLUTCH
REWIND
ENGAGING
PULLEY
REWIND
(PART
IDLER
MOTOR
(61)
BIND
IDLER
OF 7)
(7) NOT
IN
BEARING
MALFUNCTIONING
TURNTABLE
(24
or 36)
PIVOTS
(68)
and
(16)
If
the
capstan
gaged
idler (79) is
left
over an extended period
when the machine is not operating,
the idler tire may
If
running the machine in the play
mode for
several
become
hours
does
dented.
not restore the tire to normal, the idler
must be
Belt
Belt
toward
Belt
tor
track
pulley
Contaminated rewind idler
replaced.
spliced improperly.
installed
with
splice
pulley.
worn
because
pulley (61)
against
flanges
misaligned mo-
causes
one of the
(42).
joint
the belt to
capstan
guide
(8).
This
will
1.
which
may or may not be audible
but
will
generally
See
subparagraph
TABLE
4-2
FAST FORWARD
Probable
Clutch
leaf spring (17 and 32) too
weak,
usually
place.
Never attempt to
wind
takeup tension to offset other
usually
cause
appear
8.4 below.
Mode
Cause
caused
by tampering. Re-
tape
as flutter.
Malfunctions
increase
problems.
1.
Contaminated holdback
or
37).
wipes
2. Bakelite drum (23 or 35) on which
wipe
operates
Evidence of bent or
has
been
roughened.
misassembled
Check exploded view, Fig. 4-4.
Bind
in idler
guide
(8)
caused
by con-
tamination.
Bind
in turntable centering detent
(77).
en-
scrape
re-
(25
parts.
Troubleshooting
Trouble
TAPE
LOOP
THROWN
ON STARTING
MODE
(LOW
TAKEUP
TAPE
ON
TENSION)
LOOP
THROWN
STOPPING
SHUTTLING
Starting,
IN
PLAY
PLAY
OR
TABLE
Stopping,
3.
4-3
and
Shuttling
Probable
Play
takeup belt (69) contam-
Malfunctions
Cause
inated.
Nylon
drive belt (68) contami-
nated. If either the play takeup belt
or
the nylon drive belt is contami-
nated
with
oil, an overoiled motor
or
capstan
affected
bon
Slippage
is indicated. Clean all
parts
thoroughly
tetrachloride.
between play takeup belt
with
car-
(69) and clutch (19) due either
to
weak
play takeup arm spring
(41) or
bind
in play takeup pulley
bearing (part of 40).
Bind
in turntable shaft
bearings
(22 or 24) due to contamination.
Clean and lubricate
with
two or
three drops of medium weight oil.
Play
takeup
brake
release
(14) in-
operative due to
attached
relief
forward
One
spring (11)
roller (2) to drag on fast
clutch tire (16).
or
both
bind,
causing
brake
shock relief ac-
weak
or un-
shock
tuators (2) binding.
One
or
both
brake
springs
(12) off. End loops on
these
springs
to
prevent their becoming discon-
must be
shock relief
fully
closed
nected.
Bind
in turntable centering detent
(77).
Page 18
STEAM POWERED RADIO.COM
Page 19
V. Electronic
STEAM POWERED RADIO.COM
Assembly
The electronic
nel, a bias
chassis.
The record channel
VlOl
and V102A and a
(Fig.
5.3).
When
dummy
phone preamplifier, the microphone
microphone. A
will
provide the proper match for a low impedance microphone.
The MICROPHONE
arate
controls R106 and R125 respectively. Both inputs can be used
simultaneously.
plifier,
V102B.
ORD CALIBRATION potentiometer R114 at the output of this
and
can be switched to the output amplifier through the MONITOR
SELECTOR
Record equalization, accomplished in the
the cathode circuit of
age is supplied to the last
when
switch S201 on the tape transport is in the REC position.
and
switch
assembly
erase
plug
plug-in
Mixing
Signals
consists
oscillator, and a power supply, mounted on a single
consists
three-stage
J107P
transformer, available as
input
takes
in the record channel are picked off the
SI02,
V103B,
of a record channel, a reproduce chan-
of a two-stage microphone preamplifier
amplifier,
is inserted in
input
JIOIS
and LINE INPUT
place
in the
for monitoring.
is adjusted by trimmer C107.
stage
of the record amplifier,
V102B,
receptacle
matches a high
first
stage
grid
circuit of V103A, and
V103A,
J106S
in the micro-
accessory
J102S
of the record am-
V103B
V103B
impedance
equipment,
have
Plate
sep-
REC-
stage,
volt-
only
GENERAL
RECORD
CHANNEL
The reproduce channel
V104, V105 and a two-stage output amplifier V106A and
The signal
produce equalization is provided by CI 16 and R130. Level is adjusted
by
potentiometer R137.
The reproduce signal is fed to the output amplifier through the
TOR
fier
consists
follower
PUT connector
The
approximately
common to both grids of the oscillator is adjusted to eliminate any
asymmetry in wave
d-c current in the record head, causing permanent magnetization and a
resultant distorted signal.
oscillator, dependent on plate voltage,
is in the REC position.
from
SELECTOR
of one voltage amplification
output
bias
and
erase
stage
J104S.
100 kc. The NOISE BALANCE potentiometer R147
consists
the reproduce head
switch
when
V106B,
A v-u meter and resistor shunt this connector.
oscillator is an LC push-pull oscillator operating at
form.
Bias
of a two-stage reproduce amplifier,
V106B.
appears
it is in
tape
which
is transformer-coupled to OUT-
Lack of wave symmetry
level is adjusted by trimmer C113. The
at connector PIOIP. Re-
position.
stage
operates
The output
V106A, and a cathode
would
only when switch S201
introduce a
MONI-
ampli-
OSCILLATOR
REPRODUCE
BIAS
AND
ERASE
CHANNE
5-1
Page 20
BIAS
STEAM POWERED RADIO.COM
AND
ERASE
OSCILLATOR
ELECTRONIC
ALIGNMENT
ALIGNMENT
TEST
EQUIPMENT
AND
REQUIREMENTS
Head
Demagnetization
Demagnetization
Procedure
The d-c plate supply
pacitor-input L-C
transformer furnishes
HUM
BAL
is
Alignment
electronic performance. A recorder out of alignment may be character-
ized
or a combination
aligned
overall
to
determine
Alignment
sembly
drawn
in a vertical position and
interconnecting
transport
units
The
following
Demagnetize the record and reproduce
chine. The
will
generally produce an
of the recorded signal, and
any tape
Step
1:
consists
by poor frequency
at
the factory, and
performance
if
can
from
the
by removing the four
are sufficiently long for
are connected.
equipment is required for proper alignment and testing:
A.
Audio Oscillator—Hewlett-Packard Model
B.
Vacuum
C.
Ampex
corded
defined
of the
tone,
series
D.
Ampex
E.
High
Impedance
F. Small Screwdriver
erase
passed
Remove both the head cover and the mu metal shield over the
consists
filter.
a-c
adjusted for
in
of
these
checks
realignment
be
accomplished
case.
If
cables
between the electronic assembly and the tape
Tube
Alignment
at IV2
in Section 3. The tape contains voice announcements
following
reference
for reproduce
Head
Demagnetizer—Catalog
head requires no demagnetization. Magnetized
over them.
of a full
A 6.3
power
minimum
making all
response,
faults. All Ampex recorders are completely
no
outlined in Section 3 will
is
necessary
desired the electronic assembly can
screws
pull
the electronic assembly
Voltmeter—Hewlett-Packard Model
Tape—Catalog No.
ips
10
tone
tone for reproduce level adjustment, tone
response
Headphones
increase
will
gradually
wave rectifier V108, and a ca-
volt
secondary
to
all heaters. Potentiometer R150
hum.
necessary
high
noise, low
adjustments should
without
on the
access
equivalent.
db below normal operating level
sequence:
of 5 to 10 db in noise level,
winding
adjustments for proper
output,
at
any time.
removing the electronic
front
to
all adjustments
5563.
reproduce head alignment
check.
No. 704.
heads
before aligning the ma-
erase
the
on the power
high
distortion,
be
necessary.
generally
be
panel. Stand the
forward.
while
200C
or equivalent.
400C
This tape
distortion
high
frequencies on
is
heads
The
serve
as-
with-
case
The
the
or
re-
as
head assembly.
Step
2:
Place
the ON—OFF switch in the OFF position.
Step
3:
Cover the tips of the demagnetizer
ing
tape. This prevents scratching the heads. Plug the demag-
netizer
into a source
Step
4:
The head
is
the demagnetizer
sequence
erase
head, record head, reproduce head. Bring the tips
into
of
117-volt a-c power.
from
left to
contact
with
scotch tape or mask-
right
when facing the machine,
with
the record head
stack.
of
The
tips
should straddle the gap in the
the tips slowly up and
withdraw
required
Step
5:
Repeat
demagnetize the
Step
6:
Replace
alignment
The
following
channel.
A.
Reproduce Head
B. Reproduce Level Setting
C. Reproduce
D.
Reproduce Equalization
E. Hum
Step
1:
Thread the alignment tape on the machine. Terminate the
OUTPUT connector
the
phones
the tape can
assembly cover, but not the mu metal shield beneath it.
the MONITOR
start the machine in the reproduce mode. The head alignment
tone
Step
2:
Insert a small screwdriver through the
right
screw for maximum
is
either
the maximum is clearly
minor
The next tone on the tape
REPRODUCE LEVEL (P.B. LEVEL) potentiometer R137 for a vtvm
reading
10
0.4 volts rms.
The next
the
If
reproduce
worn
tape, due to head magnetization,
produce amplifier. Equalization can be checked and adjusted as indicated
below.
series
response
or otherwise
the demagnetizer
for thorough demagnetization.
step 4 on the reproduce head.
the head shield, but do not replace the head cover
will
follow.
steps
constitute the complete alignment of the reproduce
Response
Balance
vtvm
will
hand
far
db below normal operating level,
indicated on the
response
Adjustment
across
into
the phones jack so that voice announcements on
be
be announced
edge
out
of
alignment,
side
of a
peaks.
of
tones
fails to meet specifications, the trouble may be
faulty
down
very
erase
head.
Azimuth
this load. Plug a set
heard.
SELECTOR
of
maximum
is
reproduce head, a partially
Adjustment
Check
with
a 600
If
not already done, remove the head
first.
the head shield, and adjust the azimuth
output
observed on the
several
may he
15
to 20 db greater than any of
is
for reproduce level setting. Adjust the
for the reproduce
vtvm,
and
or
center
of
the
the
stack
several times, and then
slowly. Slow
It is
ohm resistor and connect
of
switch
improper equalization
minor
observed.
check
in
access
which
response
it
withdrawal
not
necessary
high
impedance head
TAPE position, and
hole
vtvm.
peaks
occurring
Make certain that
is
approximately
check.
against specifications.
erased
stack.
Run
Place
nearest
// the
the
head
on
these
Observe
alignment
of
the re-
is
to
if
a
Demagnetization
Procedure
Reproduce
Channel
Alignment
Reproduce
Azimuth
Head
Adjustment
Reproduce
Level Setting
Reproduce
Response
Check
5-2
5-3
Page 21
Reproduce equalization
STEAM POWERED RADIO.COM
quired
test
setup
in
Fig. 5-1. Set the
vtvm
volts
8000
sponse
reading
rms to
cps and
10 db
establish a reference.
adjust
on the
curve
specified frequency range.
±f4
db. Be
sure that
(P.B.
EQUAL)
and the
reproduce amplifier
oscillator
at 500 cps, and
below normal operating level, approximately
Increase
the
reproduce equalizer
at
that
point.
Response
the
oscillator
range.
Equalization
in
the
For
3% ips
as
shown
put
for a
the oscillator frequency
(P.B. EQUAL)
sponse
After
(HUM
vtvm
in
TAPE position.
procedures
procedures
are
is in the
similar
for all
audio oscillator settings
reproduce eqtialization,
in Fig. 5.1. Set the
vtvm
reading
to set
should
follow
the
oscillator
10 db
below normal operating level.
to
4000
reproduce
curve
within
cycles
response
completing stetps A through D adjusr
BAL)
connected
potentiometer
across
the
OUTPUT
R150 for
is a
bench procedure.
response
adjust
the
oscillator frequency
R130 to set
Sweep
output
the
oscillator through
should
follow
remains constant over this
machines.
for 3% ips
(P.B.
EQUAL) connect a test
at 250
cycles,
and
adjust
the
on
curve
±1/2 db.
the HUM
minimum
with
the
MONITOR
curve
its
output
reproduce
the
curve
The
only difference
and
adjust
resistance
at
that
hum as
SELECTOR
The re-
are
Reproduce
given Equalization
for a
0.4
to
re-
the
within
operation.
set-up
its
out-
Increase
R130
point.
Re-
BALANCE
seen
Hum
on a
Adjustment
Balance
The
steps
in
record channel alignment
A.
Bias
Adjustment (BIAS).
B. Record Level Meter Calibration
C. Record Head
D.
Record Equalization & Response
Step
E. Noise
F. Final
1:
Balance
Bias
Thread a tape
600 ohms
audio
nector
Step
2:
Place
just
the
level
vtvm
Step
3:
Adjust
justment carefully
Azimuth
Adjustment (NOISE BAL).
Adjustment (BIAS).
on the
and
connect a vtvm
oscillator
and
the
the
ser to 500
start
the
MONITOR
LINE
REC
reading
BIAS trimmer
(1.23
because
response.
3M
ips—For
ips
machine
After
peaking
MONITOR
the
SELECTOR
REC LEVEL control
ing
level. Switch
bias
but
bias
to
the
MONITOR
adjustment, (BIAS)
with
as
described
still
bring
are as
follows:
(REC. CAE).
Adjustment
machine. Terminate
across
cycles
machine
in the
SELECTOR
LEVEL control
volts,
or
to
peak this
bias
will
this load. Connect
to the
record mode.
in
TAPE position
for a
plus 4 dbm).
output.
affect
use
the
audio oscillator
in
Step 3 above,
in
TAPE position, readjust
the
vtvm
reading back
SELECTOR
to
(REC.
the
LINE
EQUAL).
OUTPUT
INPUT con-
and ad-^
normal operating
Make this
the
high
frequency
procedure
set at 250
to
for lYi
cycles.
and
with
the
LINE
normal operat-
INPUT position
Record Channel
Alignment
in
Bias Adjustment
an
ad-
the
Record Level
Meter Calibration
and
5-4
5-5
Page 22
Meter
STEAM POWERED RADIO.COM
Azimuth
Record
(Alternate
Record
level
Calibration
Record
Head
Adjustment
Equalization
Adjustment
Procedure)
adjust the REC. CAE potentiometer R114
'^^^'^
zero v-u ±1/2 db
the INPUT or TAPE position.
Step
600 ohms and connect a
1: Thread a tape on the machine. Terminate the OUTPUT in
Step
2:
Step
J: Record eqtialization can be accomplished
Step
2; The bench procedure for record equalization given in
Step
3: Disconnect the electronic assembly
vtvm.
audio
MONITOR
machine in the record mode, and adjust the
control
Increase
screwdriver
head shield and adjust the record head azimuth screw for
maximum
scribed under reproduce head azimuth adjustment step 2.
(REC. EQUAL).
ing
produce
in
good
a tape on the machine. Terminate the OUTPUT in 600 ohms
and
to
250
Place
and
Adjust
db
below normal operating level.
to
8000
a
vtvm
quency
lator
below
fore preferred to the procedure outlined in
record
Disconnect the a-c power
between pins 1 and 2 of the
vtvm
Remove the
the a-c power and place the ON-OEF switch in the ON posi-
The v-u meter is now calibrated, and should read
with
the MONITOR
vtvm
oscillator set at 250 cps to the
SELECTOR
for a
vtvm
With
the REC LEVEL controls at
pickup
as measured on the
normal
operating level. If
cause
of bias, connect a wave trap in parallel
600 ohm terminating
LC
circuit resonant at approximately 100 kc.
the oscillator setting to
through the
output.
the electronic assembly
channel
condition.
connect the
cycles
the MONITOR
start the machine in the record mode.
the
cps and adjust the REC. EQUAL capacitor C107 for
reading 20 db below normal operating level. Fre-
response
through the range given in the specifications.
is independent of the reproduce amplifier and is there-
response
across
must
vtvm
and connect it to the
LINE
REC LEVEL control for a
can now be checked by sweeping the oscil-
curve and
this load. Strap pins 5 and 6 of
bias
switch on TAPE position. Start the
reading 20 db below normal operating level.
NOTE
resistance.
access
Be sure to set at the correct peak as de-
from
be
properly
If
these
requirements are satisfied, thread
across
this load. Set an audio oscillator
SELECTOR
test
setup are shown in Fig. 5.2.
plug.
Jones
and
erase
oscillator tube VI02.
until
normal operating level
SELECTOR
across
vtvm
difficulty
10,000
hole
the tape transport. The re-
aligned
LINE
switch in TAPE position,
Increase
from
Connect a 1000-ohm resistor
Plug
switch placed on
this load. Connect an
LINE
INPUT.
LINE
minimum,
should be 30 db below
is experienced be-
This trap can be a
cycles.
nearest
the
without
and the
INPUT connector.
vtvm
the oscillator setting
Step
the tape transport.
P102S,
Place
REC LEVEL
the
bias
with
series
Insert a small
center
of the
disconnect-
record
head
reading 20
Step
I above. The
and connect a
P102S
together.
Reconnect
the
the
3
in
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5-7
Page 23
Record Equalization
STEAM POWERED RADIO.COM
Adjustment
(Alternate Procedure)
Noise Balance
Adjustment
Step
Step
Step
Step
Step
Step
Step
tion.
Connect
nector
J102S,
LEVEL control
Increase
EQUAL
point
through
response
output
the
capacitor CI07
as
shown
the
follows
remains constant over
3% ips—For
equalization
capacitor
at
4000
cycles
1:
Thread a tape
2:
Connect
a 0.1 mfd
OUTPUT connector.
3:
Plug
4:
•):
6:
7:
a set of
Disconnect
Turn
the
to
zero.
Start
the
Adjust
the
for a minimum
noise
in the
an
audio oscillator
set it to 250 cps and
for a
vtvm
reading
oscillator setting
to 8000 cps
to set the
in Fig. 5.2. Now
specified frequency range
the
curve throughout.
the
REC.
on 7
Vj
C107
adjustment made
instead
on the
head phones
all
inputs.
LINE
REC
machine
noise
in the
balance
reading
EQUAL
ips
capacitor
use
machine
of 8000
machine.
and a
into
LEVEL
and MIC REC
record mode.
(NOISE BAL.) potentiometer
on the
headphones.
to the
LINE
adjust
tlie
of
approximately
and adjust
response
sweep
on
the
oscillator slowly
and
check
Be
sure
range.
procedure outlined
but
with
the REC.
with
the
audio oscillator
cycles.
sensitive
the
PHONES jack.
vtvm
LEVEL controls
vtvm
or a
minimum
INPUT con-
LINE
REC
.4
volts.
the REC.
curve
at
this
to see
that
the
oscillator
for
record
EQUAL
set
across
the
R147
popping
06A
VI06B
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12AU7
TAPE TRAVEL
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450V
.
SEE
NOTE
10
^]_CI24
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V
5%
\SU
500V
ALL
CAPACITORS
RESISTORS
TO
IN
IN
CHASSIS
FOR
ELECTRONICS ASSEMBLY.
OTHERWISE NOTED.
ALL
DC
VOLTAGES MEASURED
RESPECT
NEUTRAL!, PLAY
SEE D-171116
CI25
350
ppfd.
5%,5
00V
MICROFARADS,
OHMS , tiO%, 1/2 WATT UNLESS OTHERWISE NOTED
2,
Fig.
400
WITH
20,000
RECORDS.
5-3.
VOLTS UNLESS
A/V
METER
Schematic
WITH
5-8
Page 24
jiorp
STEAM POWERED RADIO.COM
OUMWV
TAPE
PL
UC
""RAVEL
V101
6267/EF86
VIOL
6F5
0.9 (0.83)
VI02
I2AY7
VI05
6267/EF36
VI08
5Y5
0
iu,)
VI 03
I2AU7
>--t_
vio6
I2AU7
_
7)83 (76)
_
_^Jg>Ji8
278
(237)
(80)
NM
PLUG
e.
7.
e. FOR
10.
FOR
FOR
ADD
IN
INPUT
HIGH
INSTALL
150 OHM TO
INPUT
INPUT
IN
JI06S
30
INPUT
TRANSFORMER
J106S
FROM
6 TO 7 AND
II 06S .
FOCt"
FYiODCl. taOa
TI03
TRANSFORMER
IMPEDENCT
INPUT,
DU'-IMY PLUG
J107P
?.E0
Tl03
IN
REMOVE JUMPER
CONNECT
TO
A ON
s
OUTPUT
ORCUir
OHit-V
17418-07
CHM
TI03
IMPEDENCE,INSTALL
TRANSFORMER
OHM TO 50 OHM
IMPEDENCE, INSTALL
AND
C-130 FOR
J20IS
PLAYBACK
HEAD
P8
EOUALi
CII6
:.039
Si>RI30
|3,0K
RI24
+
CI14A
lOK
-
:
20
• iW
-
450V,.
V106A
1/2
^^^AAv
SI02
INPUT
1\
3>A
5%
Rise
aEK
T
TAPE
I2AU7
"
RED
PHONES
TIQA
i'
72-J "151
T'VT^
.;,
W8v\2.^
OUTPUT
BLUE
560
1
T102
"AL
3
CI25
350
ppftl
5%.5 00V
CI24
.001
5%
500V
1.
ALL
READINGS MEASURED
PER
VOLT
2.
INPUT
5.
UPPER READINGS VOLTAGE, FIRST READING REPRODUCE
1)., NM
METER.
VOLTAGE
MODE,
SECOND READING RECORD MODE,
MEANS
NOT
NC MEANS
NOT
TO
II7 VAC.
MEASURED.
CONNECTED.
GROUND
WITH
20,000 OHM
A
(set
MOTES']
41045
vloe
5Y3
+309V|—VV\r-
LI02
5.5
hy
+
+ + + ,
~^Cll4B
—^riirt,-
0.1030 —'—010'*'
At
ALL
CAPACITORS
OTHERWISE
ALL
DC VOLTAGES MEASURED
RESPECT
NEUTRAL!,
SEE
0-17416
NOTED.
RESISTORS
TO
IN
MICROFARADS,
IN
OHMS , ±10%,
CHASSIS.
PLAY
2,
FOR
ELECTRONICS ASSEMBLY.
Fig.
400
1/2
WITH
20,000
RECORDS.
5-3.
VOLTS UNLESS
WATT
UNLESS OTHERWISE NOTED.
A/V
METER
WITH
Schematic
Page 25
Reference
STEAM POWERED RADIO.COM
Symbol
83
85
84
78
78
79
80
VI.
Parts List
The following parts list provides ail information
necessary for ordering replacement parts. Always
use Ampex Catalog numbers when ordering parts. To
expedite processing, always include the following information in placing parts orders:
A. Model Number
B.
Serial Number
C. Ampex Catalog Number of Part
D.
Part Description
EXAMPLE:
Spring, Clutch "U". No. 6246, for Model 601.
Serial No. 6D0042.
Motor Mount Washer, C. R. S. 13/64 ID x 5/8 CD 2431
Motor Mount Screw, Binder Hd., 10-24 x 7/8" long MS-12-10-14C
Socket Hd. Set Screw, 8-32 x 1/8 long, cup point SS-2-8-2Y
Takeup Arm Assembly 6242-1
20 Spring, Conical, 1" dia. x 31/32" long 6137
26 Control Spring, 17/32 x 13/16" long 6218
Thrust Washer, .015 spring steel, 1/4 ID x 3/8 CD 6223-1
24 Pivot Arm 6243
29 Hub, with Shaft 6244
17 Spring, Clutch "U" 6246
19 Clutch, Play Takeup 6247
18 Disc Assembly, with small felt 6248-1
15 Disc Assembly, with large felt 6248-2
16 Clutch Assembly, fast forward, with Oilite bearing 6251
28 Link, Turntable Control 6253
27 Washer, Spring Retaining, Cup 6254
23 Collar, Drum 6293
25 Brake Assembly, Holdback
Use Replacement Holdback Brake Assembly Kit 7974
(Each ket contains two Brake Assemblies)
Lamicoid Washer, 1/4 ID x 1/32" thk 186-1
21 Oilite Bearing 422-004
22 Ball Bearing 421-019
Cotter Pin, 1/16 x 1/2" long 401-005
#4 Lockwasher, int. teeth LW-21-4C
Binding Hd. Machine Screw, 4-40 x 5/16" long MS-12-4-5C
Hex Nut, 4-40 NU-1-4C
Socket Hd. Set Screw, 6-32 x 1/8" long SS-2-6-2Y
Spring, Turntable Height 11/32 x 9/32" long 6217
Rewind Arm Assembly 6255-1
Thrust Washer, .015 spring steel, 1/4 ID X 3/8 OD 6223-1
36 Pivot Arm 6243
38 Hub, with shaft 6244
32 Spring, Clutch "U" 6246
30 Disc Assembly,^ with large felt 6248-2
31 Clutch Assembly, rewind, with Oilite bearing 6251
35 Collar, "Drum" 6293
33 Collar, Spacer 6316
37 Holdback Brake Assembly
Use Replacement Holdback Brake Assembly Kit 7974
(Each kit contains two #6320-1 Brake Assemblies)
Lamicoid Washer, 1/4 ID x 1/32" thk 186-1
* Items marked with the asterisk (*) are included in Kit #7802.
6-2
6-3
Page 27
Reference
STEAM POWERED RADIO.COM
Symbol
34
Ball
#4
XXCA
oueAtJL
Socket
64
to
An
11
48
49 vj
50
OtJ/
tlO
41
40
Turntable Height Spring,
Xriay
V^OIILI
,rt.etuaior,
owiucn iviecnanifaui
xxuxx
Rewind/Fast
Actuator, Rewind/Fast Forward
W
"Rnll
iVvXXX
Ball ^
^4fil
f"
T^onci
JJCXX X cJlXoXUiXXllg
Clnnincr
OpXXlXg,
T91 OTr
'Tot'tmY^ A v*Ty^
JTLcLy
XftAOUp
Spring
Pulley Assembly, with Oilite bearing
39 XXX 111
Cambric Wnahcr
W
diiifjl 1 L»
T.QminniH
TTQiT»nin
xjcixxxicuiu.
xidixpin
X
cXAcUp
X
yjw
xridxci
l-iCidl
GoTYi G/-»T»4xiir
ooxxi
XTnnn
XNCUIX
i:>idbb
Tnnp riniHp
X
apt; vjruxtxt;
Top Plate Casting, with grill & Oilite bearing
C203
J202D
R202
Motor
TCori
XAOp
v-'dpaciLoi
Tube
Snokpt Contant
-1
LIUO
XJxJt'tx.t;
Spring, Jones Plug Retainer
Head Cable Harness Assembly
Jones
Resistor,
Solder
Description
Bearing
Lockwasher,
•NTiif
A^A r\
INlXt,
nu.
Hd. Set
t~'t\J
oeu
Int.
teeth
ociew, o—o/s
Screw,
8-32 x 3/16"
x i/o
long
long
11/32 x 9/32" long
Oi
/\i
III /VSoeulDiy
xriay
Jrixi,
o/o^j
A
o/o
long
Forward Control Assembly
XLX^'Xl
XVXC^X^lXcXIllo
Pin
'\/'\9
X^XIX,
O/O^ A O/O
/l fi" dia
nni
1 1
XX/DT:
/AX
iXDOClHiJlV
VV
WpoTmr* 1
"D
Wdoiiei,
xveLdinei
,DOXL,
XAUOUOI
/Aoodxiuiv
kJJL/1
lllg
OCX
ew
"Rnlri
JDLXIU
AjioiniiieL
IIX
Y
"^/R" Inner
Tirr
TriloT* A T*TVI
XUXOX
/(\A Hi Q Y 1
/AX
Ulct, A Xu/ID
A ctcj£i"»v»l^lTr
111
/Abtjoinuiy
24-
do
llCl
, •
y-, 4- ri 1
TX
CA >-•
-fj-xv
x/t
loi x/f
\J
Pnaf
xrObL
XOIlg
A O
tsoTviVilTr
111 /AoEaOXllUXy
/1
A" 1 nnrr
lOIlg
TD x 7/I
4j7t
ll_/
A. 1 / X vX
/A TP Y 1
1 lAW
fxTart-W-
xxj A
x/ou"
snan.
XVlIlg
6 On x (11
\JXJ A •
/R9tT
f>ib-
uix
V/
Capacitor, Electrolytic, 2.5mfd, 220V
"MnT
Q 99
XNUL,
o—O/j
iViounLing ocrew, xjinuer iiu,,
o—o^ x o/o
min
X,
vUlltdl-'L,
Plug
20 K ohm
T^ug
111111.
fl thk
XU
LXX
Ampex
Catalog
Number
421-019
LW-2I-4C
Mi:>-i4-4—oO
XTT
T
1 Af^
JNU
-1-4C
Co
o c ov
bb-2-D-2Y
SS-2-8-3Y
6217
Reference
Symbol
_y
*
if
if
•if
81
43
82
65
*
70
42
Capstan Assembly, with flywheel, shaft & ball 9353-1
Knob, 1-1/2 in. dia.
No. 12 Lockwasher, Internal Teeth
3/8 Lockwasher, Internal Teeth
3/8 Lockwasher, Internal Teeth, Fine
1/2 Lockwasher, Internal Teeth, Fine
6-32 X 1 in. Long Bind Head Brass Machine
No. 12 Plain Brass Washer
Fibre Washer, 3/8 ID x 5/8 OD x 1/32 in.
Pan Head Sem Fastener, 6-32 x 3/8 in. long
"J"