Eico 667 - OPERATING INSTRUCTIONS (Continued); Tube Testing Details and Examples; Control Settings and Tube Handling; Line Adjustment and Leakage Evaluation

667
TUBE TESTER
‘
lEICQL,
PAGE
5
8.
Note the
number
of lines
of settings
devoted
to
the
tube
in
the
chart.
Each
line
of
settings
corresponds
to
a
section
of the
tube
(1
line
for
a single
diode,
triode
or
pentode; 2
lines
for
a double diode,
triode
or pentagrid
converter;
3
lines
for
a
duodide-
triode,
etc.)
Each
section
of the tube
is tested
by
making
the
settings
indicated
on
a single
line
of
the
chart
and
then depressing
the
MERIT lever.
Note,
however,
that
twin or
triple
section
tubes
having
identical
tube
characteristics
will
occupy
one
line
with
two
or three
plate
numbers
in the
merit
column
instead
of the
usual single
number.
Each
of these
numbers
signifies
an
individual
merit
test.
Using the
same
line
of
settings,
perform
each
individual
merit
test.
EXAMPLE:
12AT7,
twin
triode
In
the
merit
column
you will
find the
entry
16
(one, six).
Press
1
to read
merit
of the
first
triode.
Press
6 to read
merit
of the
second
triode.
All
interelement
leakage
testing
must
be performed
before
any
of the
Merit
tests,
as a
safeguard
to the
tube tester.
The
push-button
which
must
be
pressed down to
complete
the
leakage and
short
testing are all
given in
the
same
line
or different
lines
for
different
sections
of the
tube. Specific
instructions
for
making
settings
and
performing
the
required
tests
follow.
9.
The
first
3 settings
following
the
tube
type are
for the
FIL.
selector,
GRID
control and
PLATE control,
in that order.
Set these
controls
accordingly.
10.
The next
15
settings are
for lever
switches
1,
2,
3,
4,
5, 6,
7,
8, 9,
10,
11,
12,
C,
V and S
in
that order.
Set these
levers
accordingly.
11.
Check all
settings
to
make sure
that
no mistake
has
been made.
12.
Insert
the
tube
into
the socket
which
matches
its base.
(The
socket
just above
the
TRANSISTOR TEST
selector
is
for
transistors only.
All
other
sockets
are
for
tubes
only).
If
the rectangular
sub-miniature
socket
is
used,
turn the
tube so that
its index
(red dot,
black dot,
glass
spur)
matches the
dot
on the panel;
then
insert
each
lead
into
a socket terminal
in order,
not
skipping
any
socket
terminals starting
from
the
right.
If
there
is a top
cap on the
tube,
connect
it with the
cap clip lead.
13.
Allow
sufficient
warm-up time
before
proceeding.
For
battery-operated
tubes
and
h.
v.
rectifiers
(1B3 type) warm
up is
almost
instantaneous;
for most
receiving
tubes
10
to
20
seconds; for high
power
pentodes,
triodes,
and
rectifiers
20-40
seconds.
Note
that
the MERIT
test
(step
17)
should not
be
performed
until
the stated warm-up
time has
elapsed.
14. Press the
LINE button
and note
the meter reading.
Depending
on
the
filament
drain
of
the tube
under
test,
the meter will
read
more or
less
to
the
left
of the LINE
ADJ. mark
(center
scale). Holding
the
LINE
button down
turn
the LINE
ADJ.
control until
the meter
pointer
is
again
over
the
LINE
ADJ. mark. Release
the LINE
button
at the
conclusion
of this
adjustment.
15. Refer to
the first (or only)
line
of settings for
the tube and
note
the
buttons listed
in
the LEAK column.
Press down
each
of
the
buttons listed
one
at a time
(in order),
observing
the meter
each
time.
(See next
paragraph for
evaluation
of leakage readings.
)
The underlined
leakage
buttons
are for
indirectly
heated
cathodes;
when these
buttons
are depressed,
the re-
sulting
meter reading
will
be
valid
only when
the
H-K LEAK
button
is also depressed.
Failure
to
do
so
will
not normally cause
damage
to the
tube,
but will
give
too
low
a
leakage
resistance
reading
due
to
emission to other elements.
Thus, the
underlined
leakage
tests
are
of
heater
to
cathode leakage only.