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NOTE: Oil
on
anyof
the
foregoing
drivesurfaces
will
cause
"WoC'.
lnsufficient
Tape
Take
Up
1.
Increase take up by adding another
washer
(101).
2.
Clutch
felt
(90)
may be worn
-
replace
clutch
felt.
Tape Squeak
Tape
equeak
is
caused
by
faulty
tape
with in-
sufficient lubrication.
Tape squeaking
is
accentuated
by
high temperature and
humidity.
Squeaking
can
be
minimuzed
by:
1.
Cleaning headand
pressurepads wlthalcohol.
2.
Slightly decreasing pressure pad spring
(29
or
31)
tension.
"Stop"
Key
6l)
Pressed
Power
to
solenoid (122)
interrupted, amplifier
connected
to input jack, and output transformer
(T2)
seeondary disconnected,
Speaker
Key
(53)
Pressed
Connects
secondary
of
output
transformer
to
Monitor
Output
lack
(M4)
for
public address
in"Stop"
position, or monitoring
in "Record"
position.
"Plat''
Key
(50
Pressed
"Play-Record
Coil"
connected
to
first
stage
of
FUNCTION
SW
ITCH
OPERATION
ELECTRICAL TROUBLES
amplifier input.
"Speakerr key automatically
actuated
with "Play'r key,
tone
control
(RlB)
operating.
"Record" (54)
Key Pressed
"Play-Record
Coil"
connected
to
amplifier
out-
put,
bias-erase oscillator
circuit
functioning,
and tone
sontrol disconnected.
If
"Speaker" key
is
pressed,
output
is
muted
with
10Q
resistor (R45). Record level
indicators
(M6)
and
(M7)
operate
in
all
functions.
Mon-
itoring
of
"Recording" may
be
accomplished
by
insert-
ing 3.4Q speaker
in Monitor
Output Jack.
Weak Playback
Volume
0r
No
High
Frequencies
1.
Check
for
dirty
head
(25).
Clean
head
with
alcohol.
(The
plastic headcover
is removed
bypress-
ing
below the
word
"Revere"
and
then
prying
up.)
2.
Check
pressure
pads.
3.
Wrong
typeof tapeor
wind. (DuIIsideof
tape
should
be wound
'rinrr
-
"A"
wind.)
4.
Check
head
azimuth adjustment
(Page 8).
5.
Head
may
bewornbadly
or needreplacement.
6.
Check adjustment
and condition of (L1),
if
only
pre-amp
output
is
defective.
'Recorder Dead,
Pilot Light
ffi9)
Off
1.
Check
fuse
(M10).
Cause
of
blown
fuse
may
be shorted
6X5GT (V6)
or
unit
plugged
into D.C.
or
220
vAc.
2.
Check
power.cord
and
on-off
-switch
(M11).
Public Address Volume Wealg
Distorted,
0r
Dead
(Stop
&
Speaker Keys Depressed)
1. Try
another microphone,
radio, etc.,
to
see
whether
the input source
is
defective. Plug
a
3-4O
speaker
in Monitor
Output
Jack.
2.
Check
all
tubes
and voltages indicated
on
schematic diagram.
3.
Connectanaudiogenerator to
thegrid
ofeach
stage
to locate the area
of
fault.
Dead
Playbaclg Appears
To Operate
Properly
ln
Record, Level
lndicators
Operating
1. First
half of
12AX? (V1A)
defective,
(R11)
open,
or
defective function switch
contacts.
2.
Check
Monitor Output
Jack.
Check
short
in
input
grid
shield
wiring.
Check
for
defective
head.
Weak
0r
Distorted Record,
Playback
0n
Pre-
Recorded
Tape
0.K.
1.
Check
bias-erase
oscillator coil
(L2) second-
ary
for
80V
@
?0KC.
2.
Check
input
jack.
Normal
speech
1
ft.
from
microphone
should
flash the
"Normal"
indicator.
3.
Check microphone
or
other
input
source,
Microphone
must
have
3-circuitplug
with shielded
wire
connected
to
ring,
and
shield
to
body;
tip
is
not
con-
nected. One-volt input sources must have
2-circuit
plug. Failure
to push
plug
firmly all
the way into
jack
will
cause
distortion.
4.
Check
bias-erase indicator
lamp
(M8).
Lamp
should
light
if
oscillator is properly
functioning.
Recording
Level
lndicators
lnoperative,
Records
And Plays Properly
1. If
indicators
(M6) and (M?)
are
dead, lamps
may
be
loose,
or
(C22),
(C23),
(R35)
or
(R3?)
open.
2.
If
lamp
or lamps
always glow, C22
and
C23
may
be
shorted,
R36
open,
or amplifier
may
be
oscilla-
ting.
=
O n
H?
-
lll
'lt
r{
ttt
o
I
rrt
n
@
Page
ll
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