Lafayette TE-50 - Page 4

a
fectly good. Examples of the types of diodes falling into this category are the 1AX2, 1B3,
1V2, 1X2, 1Z2, 2V2, 2V3 and 3A3.
LOAD CONTROL
This control determines the amount of loading placed upon the tube under test. The smaller
the number the greater the current drawn from the tube under test.
FILAMENT VOLTAGE SELECTOR
. This selects the correct operating potential for the filament of the tube under test. The switch
should always be set before inserting a tube. Never change the setting after a tube is inserted.
POWER SWITCH
This switch turns the unit on and additionally serves to adjust it to various AC line voltages.
The HI position is for line voltages between 115 and 125 volts. The LO position is for line voltages
between 105 and 115 volts. When in doubt as to the voltage of an AC power line, set switch to HI.
Like
all
emission
type
testers,
the
Model
TE-55
provides
a
means
of
making
two
basic
tests:
1) Tests for shorts and leakages.
2) Test for quality of emission.
Tests for shorts and leakages should be carried out first and then followed by the quality test.
It
is
advisable
to
do
so
because
if
a
“shorted”
tube
were
tested
for
quality
first
it
could
cause
serious
damage
to
the
meter.
Proceeding
with
the
tests
in
the
order
recommended
will
prevent
this happening.
HOW TO TEST A TUBE FOR SHORTS OR LEAKAGES
1.
Insert
line
cord
into
AC
power
outlet.
If
the
AC
line
voltage
is
between
115
and
125
volts,
set
POWER
switch
to
“Hi”
;
if
between
105
and
115
volts
set
to “Lo”.
When
in doubt,
set
to “Hi”.
Note:
If
an
asterisk
(*)
appears
before
a
tube
listing
in
the
chart,
always
set
the
switch
to
the
“Lo”
position.