Lafayette TE-50 - Page 6

— § —
“P”
column,
set
switch
to
SPEC.
Disregard,
the
glow
of
the
indicator
lamp
in
this
position.
Set
the
elemental
slide
switches
to
the
“F”,
“N”
and
“P”
positions
(as
specified
on
the
tube
chart)
All
other
elemental
switches
should
be
set
to
the
“K”
position.
Set
the
LOAD
control
to
the
position
specified
on
the
tube
chart.
Insert
the
tube
into
its
correct
socket.
Allow
at
least
30
seconds
for
it
to
warm
up.
Read
the
quality
of
the
tube
directly
on
the
meter.
If
the
meter
pointer
does
not
move
at
all,
the
trouble
may
be
due
to
an
open
filament.
To
verify,
make the checks described in the following section.
HOW
TO
TEST
FOR
FILAMENT
CONTINUITY
Proceed
as
in
the
test
for
shorts
or
leakages.
Set
either
of
the
elemental
slide
switches
listed
in
the
filament
continuity
column
to
“P”,
with
the
other
at
“K”;
the
indicator
lamp
will
glow
if
the
filament is good. No glow indicates an open filament.
EXAMPLE
OF
A
TYPICAL
TUBE
TEST
TYPE: 6CB6
FIRST—TEST
FOR
SHORTS
AND
LEAKAGE
l.
2.
Insert
line
cord
into
AC
outlet.
Place
the
POWER
switch
to
the
appropriate
setting,
depending
on
the
AC
line
voltage.
If
in
doubt,
use
“Hi”.
Since
no
asterisk
(*)
appears
with
this
tube
listing,
.the
switch
may
be
left
in
the
“Hi”
position
if
necessary.
Yocate data for 6CB6 on tube chart. This reads as follows:
TUBE
FIL.
VOLTS
F
N
P
LOAD
FIL.
CONT.
6CB6
D
3
1
30
3,
4
Set
the
Leakage-Quality
switch
to
LEAK.