Heathkit TC-2 - Preliminary Tests

‘This
completes
instrument
construction
and
the
knobs
can
now
be
installed
on
the
panel
controls
-
Install
the
large
pointer
knobs
on
the
filament
switch
and
the
plate
control.
Index
the
filament
‘switch
knob
so
that
in
maximum
counterclockwise
position
it
indexes
at
the
.75
volt
position,
and
in
maximum
clockwise
position
it
indexes
at
the
100-115
volt
position.
Install
the
plate
con-
trol
knob
so
that
at
its
maximum
counterclockwise
position
it
indexes
at
zero,
and
in
maximum
clockwise
position
it
indexes
at
100.
The
SET
LINE
and
TYPE
knobs
should
also
be
installed
in
a
similar
manner.
The
lever
switch
buttons
should
now
be
installed
on
the
lever
switches.
In-
spection
of
the
switch
buttons
will
show
that
they
must
be
correctly
positioned
before
being
pushed
down
on
the
switch
arms.
Two
additional
buttons
have
been
supplied
with
your
kit
to
be
used
as
spares.
Retain
(hem
for
possible
future
use.
PRELIMINARY TESTS
Plug
the
line
cord
into
a
117
volt
AC
50
to
60
cycle
supply
source.
Never
use
25
cycle
or
DC
supply
voltage,
as
the
power
transformer
will
suffer
severe
damage.
Turn
the
panel
switch
to
its
ON
position.
The
roll
chart
panel
lamps
should
immediately
light,
and
the
meter
pointer
will
deflect
to
mid-scale.
With
the
use
of
the
SET
LINE
control,
it
should
be
possible
to
adjust
the
meter
pointer
to
the
meter
line
test
position.
It
is
normal
for
the
range
of
adjustment
to
be
on
the
high
side
of
the
meter,
rather
than
toward
the
low
end.
This
is
understandable
in
view
of
the
fact
that
when
heavy
current
drain
tubes,
such
as
rectifiers
drawing
2
and
3
amperes
on
the
filament,
are
being
tested,
the
reading
will
drop
somewhat
and
it
will
be
necessary
for
the
SET
LINE
control
to
be
readjusted
to
the
line
test
position,
It
the
neon
short
lamp
lights
up
during
any
of
these
preliminary
tests,
turn
the
Tube
Checker
off
immediately
and
systematically
trouble-shoot
the
circuit
for
possible
cause
of
difficulty.
‘The
short
test
should
not
indicate
any
glow
during
the
preliminary
test
procedure
if
the
instru-
ment
is
correctly
wired.
Should
difficulty
be
encountered,
a
voltage
check
of
the
power
trans~
former
would
be
helpful.
Use
an
AC
voltmeter
and
refer
to
the
schematic
for
the
proper
volt-
ages
that
would
normally
be
obtained
at
the
various
windings.
If
preliminary
tests
indicate
that
the
Tube
Checker
is
functioning,
the
action
of
the
checker
can
be
further
teated
by
making
actual
tests
on
a
variety
of
tubes
that
may
be
available.
,
CABINET
INSTALLATION
‘The
Tube
Checker
can
now
be
installed
in
the
cabinet
or
carrying
case,
When
the
panel
is
in
place,
you
will
note
that
there
has
been
a
slight
space
provided
between
the
cabinet
walland
the
edge
of
the
panel
to
accomodate
any
small
variations
that
may
occur.
After
properly
centering
the
panel,
small
holes
should
be
drilled
in
the
wood
corner
supports,
so
that
the
panel
mounting
screws
can
be
installed,
If
a
drill
is
not
available,
a
starting
hole
can
usually
be
made
with
&
small,
sharp
screwdriver
or
a
small
awl.
USING
THE
HEATHKIT
TC-2
TUBE
CHECKER
‘The
Heathkit
Tube
Checker
will
provide
a
number
of
varied
tests
and
these
are
outlined
in
the
steps
below.
The
following
steps
should
always
be
used
as
a
guide
in
setting
up
tube
testing
procedure,
(1)
With
power
cord
connected,
move
roll
chart
to
listing
of
the
tube
to
be
tested,
and
turn
SET
LINE
control
until
meter
pointer
is
at
LINE
TEST
point.
(2)
Set
the
TYPE
switch
to
the
number
shown
on
the
chart.
(3)
Set
the
FILAMENT
selector
to
the
voltage
shown.
(4)
Set
the
PLATE
control
according
to
chart
information.
(5)
Set
LEVER
switches
to
TOP
and
BOTTOM
positions
as
shown
in
top
and
bottom
columns
in
chart.
(6)
Insert
tube
and
re-set
the
SET
LINE
control
if
necessary.
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