Zenith Royal 1000 - Repair and Alignment; Recommended Repair Equipment; Signal Tracing Methodology; Alignment Procedures

If
the
transistor
is
suspected
of
being
defective
for
any
other
reason than a barrier short, the only reliable check is to sub-
stitute
а
new
transistor
and
then
check
performance.
There
is
a possibility that if transistors are replaced in the IF or RF
circuit,
these
circuits
may
need
re-alignment
as
the
result
of
slight differences in transistor characteristics.
SIGNAL TRACING
Past practices used in radiorepair commonly known as “Screw
driver testing’’ in which the B + at the plate of the tube is
shorted
to
ground
to
check
for
“clicks”
in
the
speaker,
is
definitely not recommended. This practice would be compar-
able to shorting the collector of a transistor to ground which
could damage the transistor. Standard point to point signal
checking with the proper RF, IF and audio signals, should
only be used.
REPAIR EQUIPMENT
The
following
list
of
equipment
is
what
we
recommend
and
use
for repair
of transistor
chassis:
1.
An
RF
signal
generator
supplying
frequencies
from
455
Kc
to 23 Mc.
2.
An
audio
generator
or
an
audio
signal
source
to
be
used
for
signal
tracing
after
the
diode
detector.
3.
A
VTVM
with
a
good
low
range
voltage
scale
and
a
reli-
able
resistance
scale.
4.
M209B
Dazor
floating
lamp
&
magnifier
or
equivalent.
5.
А
set
of
optometrist
tools—pliers,
cutters,
picks,
etc.
6.
A
soldering
iron
with
a
very
fine
tip,
not
to
exceed
35
watts.
ALIGNMENT PROCEDURE
CONNECT GEN. TO INPUT SIG.
BAND| SET DIAL
FREQUENCY
AT
TRIMMERS
PURPOSE
OPER. DUMMY ANTENNA
1
One
turn
loop
coupled
T1,
T2,
T3,
T4
Align
I.F.
loosely
to
Broadcast
Wavemagnet
*2
One
turn
loop
coupled
600
Ke
Rock
gang,
Alignment
of
BC
loosely
to
Broadcast
Adjust
C52B
at
Wavemagnet
3 1600 Kc
4 One
*5
Turn
Loop
Alignment
of
ENT
=
А
В.С.
mi
Coupled
660
cr
=
6 Loosely to
7
Broadcast
Wavemagnet
8
9
One
turn
loop
coupled
Place
Detachable
1
Wavema
gnet
in
center
oosely
to
Detachable
of
a
metal
framed
win-
Wavemagnet
dow
&
adj.
C28
for
max
*
10
2.1
Mc
2-4
Mc
Rock
Alignment
of
S.W.
3
Feet
L25,
L17,
L7
озс.,
mixer
&
antenna
of
Wire
А
11
3.9
Ме
2-4
Mc
C26E,
C26D,
Аниса
of
Approximately
C26B
mixer
&
antenna
12
l
Foot
REPEAT
OPERATIONS
10
&
11
*
13
and
Parallel
4.25
Mc
4.25
Mc
Rock
L24,
L16,
L6
|
Alignment
14
from
8.75
Mc
|
4-9
Mc
|
8.75
Мс
С26Е,
С26С,
С26А
t
|
SS
зерна
о
15
REPEAT
OPERATIONS
13
%
14
Extended
Short Wave
16
|
9.7
Мс
31
meters
.
9.7
Mc
|
123,
L15,
L5
Waverod
ill
17
пам
|25
meters
|
11.8Me
|
122,
L14
14
|
Oscillator,
18
15.2
Mc
|19
meters
|
15.2
ме
|
1.21,
1,13,
L3
Mixer
and
19
17.8
Mc
17.8
Mc
|
L20,
L12,
L2
Е
|
[
20
21.6
Mc
13
meters
21.6Mc
|
LI9,
L11,
L1
*
NOTE:
Rock
tuning
condenser
when
making
alignment
under
Operations
2, 5,
10,
13.
и