HH Scott 310E Reference manual
111
Powdermill
Road,
Maynard,
Mass.
SERVICE
BULLETIN
For
MODEL
310E
BROADCAST
MONITOR
FM
TUNER
SPECIFICATIONS
(These
specifications
are
minimum
-
all
H.
H.
Scott
310E
tuners
must
meet
or
exceed
these
figures.
Usable
Sensitivity
(IHFM)
(For
less
than
3R
Total
Noise,
distortion,
hum
-
30
db)
1.9
microvolts
Cross
Modulation
Rejection
85
db
Signal
to
Noise
Ratio
65
db
below
100%
modulation
Total
Harmonic
Distortion
0.5%
Frequency
Deviation
0.02%
Frequency
Response
20-15,000
cps
+
1
db
Capture
Ratio
2.2
db
Selectivity
50
db
Spurious
Response
Rejection
90
db
Hum
66
db
AM
Suppression
60
db
Separation
In
excess
of
30
db
Audio
Output
(100%
modulation)
4
-
6
volts
Tuning
Range
87-109
mc
Accuracy
of
Calibration
0.5%
Output
Impedance
3000
ohms
Minimum
Recommended
Load
Resistance
100,000
ohms
Minimum
Recommended
Cable
Capacitance
1000
mmfds
Maximum
Recommended
Length
of
Output
Lead
70
feet
Range
of
Line
Voltage
and
Frequency
Power
Consumption
-
AC
ONLY
-
DO
NOT
OPERATE
WITH
DIRECT
CURRENT
GENERAL
SERVICE
NOTES
105-125
volt
50/60
cps
50
watts
Service,
other
than
replacement
of
either
pilot
lights
or
vacuum
tubes,
is
usually
not
required.
If
the
tuner
is
not
operating
properly,
all
external
connections
should
be
checked
to
make
sure
that
the
difficulty
is
in
the
tuner.
Generally,
it
is
advisable
to
replace
the
connection
to
the
tuner
with
a
tape
recorder
or
similar
device
to
check
out
the
amplifier
performance,
If
the
difficulty
appears
to
be
located
in
the
tuner,
the
level
controls
should
be
first
checked,
to
insure
that
they
are
rotated
away
from
their
extreme
counter-clockwise
positions.
Then,
the
vacuum
tubes
should
be
checked
by
replacing
them
with
new
ones,
one
by
one.
The
tubes
should
be
tight
in
their
sockets
and
provided
with
shields
where
applicable.
Tube
defects
frequently
do
not
show
up_in
a
tube
tester.
Only
operation
in
the
tuner
will
insure
the
proper
working
of
a
vacuum.
())
D-310E-2
Tuning
Dial
Pilot
Light
Replacement:
1.
First
set
the
tuning
dial
so
that
the
heavy
white
lines
line
up
with
the
pointers
on
the
dial
and
the
logging
scale
is
towards
the
top
of
the
panel.
In
this
position,
the
tuning
condensers
are
closed,
Unscrew
and
remove
the
tuning
knob
and
dial.
This
will
permit.
access
to
the
pilot
light
which
is
a
#47
bulb.
After
the
bulb
has
been
replaced,
use
the
following
procedure:
1.
2.
Close
the
condenser
plates
by
rotating
the
condenser
to
the
extreme
counter-
clockwise
position.
Replace
the
dial,
lining
up
the
heavy
white
lines
of
the
dial
with
the
pointers
and
keeping
the
logging
scale
toward
the
top
of
the
front
panel.
Meter
and
Indicator
Pilot
Light
Replacement:
1.
Remove
the
pilot
light
assembly
by
inserting
a
sharp
instrument
(a
screw
driver
or
knife)
between
the
Control
Shield
and
the
Assembly
Clip.
2.
Remove
the
old
bulb
and
install
the
new
#47
bulb.
3.
Reinstall
the
light
assembly
by
snapping
it
into
the
hole.
TEST
PROCEDURE
Note:
No
attempt
should
be
made
to
align
the
tuner
or
repair
it
unless
the
person
so
doing
has
had
extensive
experience
in
tuner
alignment
and
repair
procedures
and
has
the
necessary
laboratory
equipment.
Without
proper
experience
or
equipment,
the
repairman
may
seriously
damage
the
tuner.
Equipment
Needed:
VTVM
(AC)
Oscilloscope
VOM
Distortion
Meter
FM
Signal
Generator
(must
be
measurements
210AB
or
equivalent)
MX
Generator
Audio
Generator
15
ke
Low
Pass
Filter
Insulated
Alignment
Tools
Set
Controls
to
the
Following:
Level
pots
Max
cw
Separation
pots
Max
ccw
Mono
Threshold
(top)
Max
cw
Stereo
Threshold
(top)
Max
cw
Comp.
phase
adj.
Max
cw
AGC
sw.
Normal
Dynaural
Squelch
(front)
Max
cew
('0')
Stereo
Threshold
(front)
Max
cew
('0O')
Selector
sw.
MONO
Function
sw.
Normal
(2)
830
Settings:
8
#
@
we
TM
mhoean
ws
fw
400
cps
audio
input
(balanced),
about
1.5v
p-p,
to
audio
oscillator
input.
Input
Selector
-
Audio
Osc.
pos.
Pilot
-
OFF
Sub
and
Main
-
ON
Vertical
input
sel.
-
Composite
signal
Horizontal
input
sel.
-
Left
Ch.
Input
Left
and
Right
Channels
-
Pos.
(+).
(Equivalent
MONO
output)
Composite
signal
output
-
to
FM
Generator
Mod.
input
Horizontal
(synch)
output
-
H
input
on
scope.
Power
sw.
-
ON
Test
Set-up
Check
Out:
a.
Cc.
Using
any
known
operating
tuner,
set
to
MONO
position.
Connect
FM
Generator,
internal
400
cps
modulation,
75
kc
deviation,
100
uv
output,
at
either
92
or
106
to
tuner.
Observe
output
on
VIVM
and
scope
and
record
output
voltage.
Switch
FM
Generator
to
External
Mod.,
300
kc
deviation;
using
same
frequency
and
R.F.
Output,
adjust
Audio
Osc.
Amplitude
control
for
same
output
reading
as
above.
All
checks
can
now
be
done
using
EXT.
Mod.,
300
kc
deviation
on
FM
Gen.
Note:Allow
tuner
and
test
equipment
to
warm
up
fully
before
beginning
alignment.
Adjust
line
voltage
for
117
volts.
Remove
bottom
cover
of
tuner.
Always
tune
primary
and
secondary
of
I.F.
transformers
at
the
same
time,
using
one
alignment
tool
in
each
hand,
1.
MONO
ALIGNMENT
AND
SENSITIVITY
CHECK
Front
End
and
IF
Alignment
With
about
10
uv
Generator
output,
align
and
peak
front
end
for
max.
output,
With
3
uv
input,
align
IF's
for
max.
audio.
With
2K
uv
input,
align
detector
for
minimum
distortion.
With
5
uv
input,
scope
probe
to
CPM
1.0
uf
coupling
capacitor
(after
6U8),
scope
SYNC
to
INPUT,
observe
undistorted,
symmetrical
Lissajous
pattern
on
scope
-
this
must
be
a
near-perfect
Lissajous
pattern
-
if
not,
IF's
must
be
touched
up
(starting
with
last
IF
can).
Right
ch.
selector
on
830
to
NEG
(-),
observe
near-perfect
butterfly
pattern
on
scope.
If
not,
repeat
steps
b
and
d,
Sensitivity
and
Distortion
f.
g.
h.
Return
830
right
ch.
sel.
to
pos.
(+).
Scope
probe
to
output.
Scope
SYNC
to
"INT",
Measure
sensitivity
of
tuner
with
4.4
uv
RF
input.
Must
obtain
30
db
useable
sens.
at
92,
98,
and
106
mc.
Audio
output
2-4
volts.
Recheck
distortion,
2K
uv
input.
400
cps
-
max.
dist.
of
0.5%.
At
10
kc
max.
dist.
of
2.0%
(output
taken
from
detector
output
for
10
ke
only).
Reduce
RF
input
from
1K
uv
to
0
uv,
audio
output
level
drop
15
+
1
db.
FM
Hum
Check
i.
Return
modulation
to
400
cps.
RF
input
to
10K
uv
at
either
92
or
96
or
106,
take
reference
reading,
turn
modulation
"OFF",
Minimum
of
54
db
drop
in
output
must
be
noted,
(3)
De-emphasis
Check
j-
Modulation
400
cps
with
10K
uv
RF
input.
Change
mod.
to
8
kc,
note
decrease
of
12
+
2
db
in
output.
Repeat
for
stereo.
Leave
tuner
in
Mono-short
pins
2
and
3
on
stereo
switching
tube
(12DW7)
to
switchover
to
stereo.
Calibration
Check
k.
Check
calibration
against
stations
-
Max.
tolerance
+
.2
mc,
Filter
Check
1.
With
output
meter
and
scope
connected
to
ch.
A.
output
jack,
external
modu-
lation
10
kc,
with
pilot,
830
L
=
+,
R
=
+,
check
for
less
than
1
db.
change
in
output
when
switching
between
normal
and
sub
chan.
filter.
Switch
to
Stereo
Filter
and
note
output
drops
6-8
db.
Now
switch
830
to
L
=
+,
R
=
-,
and
switch
between
Sub
Chan.
Filter
and
Stereo
Filter
and
note
less
than
1
db
change
in
output.
Switch
between
Normal
and
Sub
Chan.
Filter
and
note
6-8
db
lower
in
Sub
Chan.
Filter
position.
Audio
Hum
Check
m.
Dynaural
Squelch
to
'O',
level
pots
minimum
-
max.
hum
1
mv.
Level
pots
max.
Max.
hum
3
mv
both
channels.
MULTIPLEX
ALIGNMENT
Pilot
Adjustment
a.
RF
input
3K
uv.
Pilot
"ON",
sub
and
main
ch.
"OFF",
10:1
scope
probe
to
pilot
junction
point
(after
diodes
from
T-502)
peak
T-501
(bottom
and
top)
and
L-501
for
maximum
pilot
signal
as
seen
on
scope.
Calibrate
scope
and
measure
pilot
level
-
specifications
are
5
-
15
volts.
Oscillator
Sync.
Adjustment
b,
Scope
probe
to
output,
sub
and
main
ch.
"ON",
Right
channel
"OFF",
pilot
"OFF",
scope
Sync
to
input,
tuner
to
Ch.
A
output.
Short
primary
of
T-501,
short
pins
2
and
3
on
stereo
switching
tube
(7247-12DW7),
adjust
T-502
for
zero
beat
as
seen
on
scope.
Remove
both
shorts,
scope
SYNC
to
INT.
High
Frequency
Separation
Adjustment
c.
Pilot
still
"OFF",
tuner
still
in
MONO,
830
left
ch.
pos.
(+),
Right
ch.
OFF,
Audio
modulation
to
12
kc.
Change
830
sync.
lead
from
H
input
on
scope
to
sync.
terminal.
Switch
scope
SYNC
to
EXT.
This
now
provides
external
sync.
for
scope.
The
external
sync.
coming
from
830.
When
checking
left
ch.,
830
Horiz.
sel.
sw.
to
left
ch.
when
checking
right
ch.,
830
horiz.
sel.
sw.
to
right
ch.
to
maintain
sync.
10:1.
Scope
probe
to
CPM
1.0
uf
(after
6U8).
Adjust
scope
to
obtain
pattern
and
with
composite
phase
adj.
balance
middle
portion
of
scope
pattern
for
best
symmetry
and
flatness.
830
left
ch.
OFF,
Right
ch.
pos.
(+),
repeat
adj.
of
middle
portion
of
scope
pattern
for
best
symmetry
and
flatness.
If
necessary, slightly
touch-up
L-501
for
best
flatness
and
balance
of
this
middle
part
of
scope
pattern,
Low
Frequency
Separation
Adjustment
d.,
Audio
Mod.
to
400
cps.
Pilot
"ON".
830
SYNC
lead
back
to
H
input,
scope
sync
to
INT.,
scope
probe
to
output,
tuner
to
stereo,
output
from
ch.
A,
830
to
right
ch.
pos.
(+),
Left
ch.
OFF.
Adj.
scope
to
obtain
pattern
and
(4)
adj.
ch.
A.
separation
pot
for
minimum
output
observing
scope.
Slightly
touch-up
L-501
for
minimum
output.
830
to
Left
ch.,
tuner
output
from
ch.
B
and
adj.
ch.
B
separation
pot
for
minimum
as
outlined
above.
Repeat
between
A
and
B
until
no
further
improvement
is
seen.
Final
Separation
Measurements
to
be
done
in
each
channel,
in
order
shown:
e.
Audio
Modulation
Minimum
Separation
12
KC
28
db
3
KC
30
db
400
cps
34
db
If
separation
specs
are
not
met,
recheck
IF's
for
proper
alignment
using
separation
scope
pattern
-
slightly re-align
IF's
for
min.
separation
at
frequency
where
the
specs
are
not
met,
Also
recheck
steps
2.b,
c,
and
d,.
Also
recheck
67
kc
trap
for
proper
null.
AUDIO
OUTPUT LEVELS
(Rear
Chassis)
Audio
modulation
400
cps
830
left
and
right
channels
to
Pos.
(+).
RF
input
to
100
uv.
Tuner
to
MONO.
Note
and
record
output
voltage
(2-4
volts)
tuner
to
automatic
stereo,
then
to
stereo,
output
must
remain
within
1.5
db
of
mono
level,
Adjust
each
level
control
for
0
db
on
3
v
scale.
MONO
THRESHOLD
ADJUSTMENT
(Top
Chassis)
RF
input
to
100
uv.
Dynaural
Squelch
control
(front
panel)
to
"10."
Adj.
Mono
Threshold
Adj.
(on
top
chassis)
until
mono
relay
activates
and
signal
cuts
out.
Leave
adjustment
at
this
point.
Reduce
RF
input
to
3
uv,
turn
Dynaural
Squelch
control
slowly
towards
"0,"
note
that
MONO
relay
deactivates
and
signal
reappears
-
this
must
happen
between
3
and
6
on
pot.
Attach
antenna
to
input,
check
to
see
that
Dynaural
Squelch
pot
operates
between
3
and
6
on
interstation
"noise"
all
across
the
band.
Leave
Dynaural
Squelch
pot
at
"to"
Mono
light
must
go
out
when
relay
is
activated.
STEREO
THRESHOLD
ADJUSTMENT
(Top
Chassis)
RF
input
to
3k
uv.
830
right
ch.
OFF,
tuner
output
from
ch.
A,
tuner
to
Automatic
Stereo,
Stereo
Threshold
pot
to
"10."
Adjust
Stereo
Threshold
Adj.
(on
top
chassis)
slowly
until
stereo
relay
activates
and
signal
becomes
MONO
-
leave
adj.
slightly
beyond
the
mono
switch
-
over
point
and
reduce
RF
input
to
10
uv.
Turn
Stereo
Threshold
pot
slowly
towards
"0"
until
stereo
relay
deactivates
and
signal
becomes
stereo
-
this
must
occur
between
O
and
2
on
pot.
If
not,
readjust
Stereo
Threshold
Adj.
(on
top
chassis).
With
relay
activated
(stereo
signal
switched
to
mono)
turn
selector
sw.
to
Stereo
and
note
that
the
mono
relay
activates
and
signal
cuts
out.
Now
increase
RF
input
until
both
relays
deactivate
and
stereo
signal
appears
at
output
-
This
must
occur
between
10
to
20
uv
input.
Stereo
light
ON
in
Stereo,
out
when
switched
to
MONO.
Selector
sw.
to
MONO,
Dynaural
Squelch
and
Stereo
Threshold
pot
to
"0,"
seal
necessary
pots.
FINAL
LISTEN
CHECK
Check
all
inputs
and
outputs
(including
phone
jacks)
switches
and
controls
for
proper
operation.
Check
overall
appearance.
Check
for
proper
switching
of
stereo
and
mono
lights.
If
there
are
any
problems
or
questions,
write
to:
Technical
Services
Department
H. H.
SCOTT,
INC.
111
Powder
Mill
Road
Maynard,
Massachusetts
(5)
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__
POSITION
FUNCTION
I
POWER
OFF
2
STEREO
3
-———
SUB
CHAN.
FILTER
4
STEREO
FILTER
Gis)
15x
(5)
2c00
@
TYPE
3ZIOE
FM
MULTIPLEX
STEREO
TUNER
ZIOE
CIRCUIT
DIAGRAM
H.
H.
SCOTT,
INC.
MAYNARD,
MASS.,
U.S.
A.
e°
D-3IOE-Cl_
sve.
ecm
PMANT,
2
4
4RSB
6BO7A
EM
RE.
MAYRARD
ASS
8
A.
OT
RW
OSC,
@.
M4.
SCOTT,
INC.
Mix
THREE
*47
LAMPS:
:
r
B+
Filters
a
ee
Me
My
Dysaural
R
(7)
mm
8)»
:
me
Relay
Driver
Rectifier
Output
Amp.
ier
Front
Panel
Switches
and
Controls
(5)
Detector
Can
.....eeceeceee
TRV-10.7D
(6)
19
ke
Can
...
cc
eee eee
eee
=
TRV-.02T
Function
Switch
.........
SRW-44-11
(7)
38
ke
Osc.
Can
..........
TRV-.O4T
Selector
Switch
.........
SRW-13
(8)
Dynaural
&
Stereo
Relays
Dynaural
Squelch
Control,
RCV-1MST-3B
(under
shield)
........
K3-CCA
Tape
Jack
.....eeeeeeeeee
J3-ST
(9)
L &
R
Separation
Pots
....
RCV-10K
PH
Stereo
Threshold
Control.
RCV-100KL-3B
(10)
SCA
Coil
...ceceeececeeeee
LV-05
Tuning
Meter
......-2...-
M-SS~7
(11)
19
ke
Coil
........0.6-205-
LV=05
A.G.C.
Switch
....eeeee--
SS-22-2
(12)
Mono
Threshold
Pot
.......
RCV-100K
PH
Tuning
Dial
Light
Socket.
XPL-U5
(13)
Stereo
Threshold
Pot
.....
RCV-500K
PH
Snap-in
Light
Sockets
...
XPL-U4-3
(14)
Composite
Phase
Pot
......
RCV-l00K
PH
(15)
Hum
Pot
..ceceecesccceceee
RWV-100
Main
Chassis
Major
Parts
and
Controls
(16)
Power
Resistor
.......++.-
RWS-10-450
(3x150)
(17)
-
B+
Filter
......eeeeeeeees
CEC
2x40/250-25/25
lst
IF
Can
............-.
TRV-10.7
IF
(18)
Bt
Filter
.........0s-006.
CEC
4x40/300
2nd
IF
Can
........+.++..
TRV-10.7
IF
(19)
Fuse
PoSt
.scecscscsceecee
XF-3AG
3rd
IF
Can
....eeee000e+-
TRV-10.7
IF
FUSE
wee
c
ec
eeeeeceesescvcs
FSBH.7
4th
IF
Can
.......0+++2++-
TRV-10.7
IF
(20)
L
& R
Level
Pots
.........
RCV-500K
PH
(8)
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