Heathkit SB-10 - Voltage Chart

AREA
TUBE
PIN 1
PIN
2 PIN
3
PIN
4
PIN
5
PIN
6
PIN
7
PIN
B
PIN
9
BAL.
MOD.
DECK
'A"
12AT7
300
0
3.2 0
0
300
0
3.2
6.3
VAC
'8"
12AT?
300
0
3.2
0
0
300
0
3.2
6.3
VAC
RF
DECK
"A"
6CL6
5.5
0
250
6.3
VAC
0
300
0
250
0
"B"
6BQ5
NC
0
7.8
6.3
VAC
0 NC
300
NC
250
AUDIO
AND
PHASING
DECK
'A'
1zA)Kl
160
0
1
0
0
160
0
1
6.3
VAC
"8"
6AL5
0to
0.
1
-0.?
6.3
VAC
0
0to
0.1
0
-0.
?
0
0
'c"12AT7
135
0
1.?
0
0
135
0
L.7
6.3
VAC
"D"12AT7
300
0
3.2 0
0
300
0
3.2
6.3
VAC
'F"
12AT?
300
0
3.6
0
0
270
0to
0.
I
-
,_"
2.7
L1
2.5
6.3
VAC
VOLTAGE
CHART
condition,
unless
otherwise
specified,
are as
foilows:
Input
and
output
coaxial
cables
disconnected.
Function
switch
in
"Manual".
Carrier
null
controls
at
mid-position.
AII
other
controls
full
CCW.
Measurements
taken
with
a Heathkit
Model
V-?A
VTVM
between
pin
and
ground.
*With
the
f unction
switch
in
"VOX".
NorE:
with
the
function
switch in"vox",
all
voltages on
tubes
on
the
Bal.
Mod. and
RF Decks
will
be
zero with
the
exception
of filament
voltages.
Inspection
of
the
RF
phase
shift networks
and balanced
modulator
voltages
may
be called for
if
either
the
carrier
or unwanted
sideband
suppression
cannot
be
obtained.
If
tle carrier
is not
suppressed
with
both
carrier
null
controls in
the middle
third
of their
range,
balanced
modulator
trouble
should
beassumed-
Check forabad
12AT?
in the
balanced
modulat"ol
improper
voltages,
or
wiring
error.
IJ unwanted
sideband
suppression cannot
be obtained,
ctreci
ttre
nir
pnase
Jiriti
network
connections,
especiallv
the
stacking and connection
of
the
precision
mica
capacitors.
If unwanted
sideband
suppression
is
poor
after the
above
checks,
measure
the
two
AC voltages
at
pins_
Dl
and D6,
with
steady 1000
cps
under signal input.
They
should
be equal
or it
should be
possible
to
ma]<e
them
equal
by adjusting
the
audio balance
control.
When the
two
voltages
are
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59