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The designation
"P"
and
"G" refer
to the
plate and grid contacts
of the socket
indicated
by the number following.
For
example
G2 would
indicate the grid contact
of
the second socket, P6
would
indicate
the
plate contact of the sixth tube
socket.
Polarity
of the various
Radiotron
sockets
are not
alike.
Figure
7
illustrates
the
correct polarity
of the filament
terminals for each socket
in
addition to the location
of
the
plate
and grid terminals.
CONTINUITY TEST CHART
Terminals
H
-A
to
+1.1,
2,
and
3
+A
to
+F4,
6
and
6
-A
to
-F1,
2, 8, 4,
5
and
6
-A
to
-F6
(Open and
close
switch
while making
test)
-F4
to
+F4
-B
to
+185B
-B
to
+671/2
-B
to frame
-B
to
GI,
G2 or G8
-B
to P4
-B
to G4
+F4
to
+F3
+F6
to
+A
+671/2
to
Pl
+671/2
to P2
+671/2 to P3
+45
to
P4
+185
to P5
+135
to
Output
P6 to Output
-9C
to
G5
-9C
to
G6
Antenna to frame
G1
to frame
Stator
condenser
No.
1
to G2
Stator
condenser
No.
2
to G3
Correct Effect
Closed
Closed
Closed
Open or closed ac-
cording to posi-
tion of switch
Closed
Open
Open
Closed
(Switch closed)
Closed
Open
Closed
(very weak)
Closed
Closed
Closed
Closed
Closed
Closed
Closed
Closed
Closed
Closed
Closed
Closed
Closed
Closed
Closed
Incorrect Effect
Caused By
Open
volume
control, filament resistor,
or wiring
Open filament
resistor
or wiring
Open switch, defective cable or wiring
Defective switch or connections
Open detector grid resistance
Defective
1
mfd. by-pass condenser
Defective
1/2
mfd. by-pass condenser
Open ground connection to chassis
frame
Open secondary
of radio -frequency
transformers
or
grid resistances
Defective
A.
F. by-pass condenser
Defective
grid
leak or detector grid
resistance
Open
volume control
Open filament resistor
Open
primary
1st R.
F. Transformer
Open
primary
2nd R.
F. Transformer
Open
primary 3rd
R.
F. Transformer
Open
primary
1st A. F.
Transformer
Open
primary
2nd
A.
F.
Transformer
Open Connection
Open Connection
Open secondary of first audio
trans.
Open secondary of second audio
trans.
Open antenna inductance or connections
Open antenna inductance or connections
Open grid resistance No.
1
Open
grid resistance
No.
2
(22)
IMPORTANT PRECAUTIONS
1.
As a fixed
resistor
is
used
in
the filament circuit, it
is
important that
all the
Radiotrons
be in
place before
turning
on
the operating
switch.
This
is
to
protect
the
Radiotrons from
excessive filament
voltage
when
the
total
load
is
not
in
the circuit.
2.
The
main
tuning
condensers
are electrically and mechanically aligned
at
the
factory. Tampering
with or
handling
of
any kind
that
may affect the alignment of these
condensers
is
to
be
avoided.
The
screws on the side of
the assembly should not
be
touched
because any movement,
even
though slight, may seriously affect the overall
efficiency
of
the Radiola. This would
be
especially noticeable
on weak
signals.
15
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