Section IV. OPERATING TEST SET
and SUPPRESSOR selector switches select the
t e s t socket connections so that correct test volt-
Before operating the test set, perform the
ages are applied to the elements of the tube
starting procedure below to check the general
under test. For clarity, these selector switches
operation of the equipment. If the results ob-
will, in some instances, be referred to collec-
tained from the procedures in b through e b e -
tively as "the selectors". When referred to col-
low are satisfactory, the test set is ready for
lectively, they are considered in the same order
N o t e . If an abnormal indication is obtained during
the starting procedure, refer to the equipment perfor-
m a n c e checklist (par. 35) for corrective measures.
(1) Locate the type number of the tube
a. C o n n e c t t h e t e s t s e t t o a 1 1 5 - v o l t a c , 5 0 -
to be tested in the test data book (fig.
t o 1 , 0 0 0 - c y c l e p e r s e c o n d ( C P S) , p o w e r s o u r c e .
b. S e t t h e P O W E R s w i t c h t o t h e O N p o s i -
(2) T u r n
tion; the PILOT lamp should light.
knob to the position shown in the F i l
c. P r e s s
column of the test data book.
Set the selectors to the letters and the
meter pointer rests over the LINE TEST mark
numbers indicated in the S e l e c t o r s
on the meter face.
column in the test data book. Be sure
- LINE ADJ.
d. R e l e a s e
the numbers indicated by the selector
e. C h e c k
knobs are the same, if read from left
to right, as the numbers in the test
A, the right FILAMENT selector at
P, and the GRID, PLATE, SCREEN,
E x a m p l e : To test a tube type 6SN7, the
Selectors column in the test data book indi-
lectors at 0, 0, 0, 2, and 2, respectively.
cates that the selectors are to be set at
HY4-5062. Start at the left and turn the
FILAMENT (left) selector knob to H, and
through the five SHORTS positions.
the FILAMENT (right) selector knob to Y.
Turn the GRID selector knob to number 4;
should glow in positions 2 and 3 of
the PLATE selector knob to number 5; the
SCREEN selector knob to number 0; the
CATHODE selector knob to number 6; and
that the short test circuit is function-
the SUPPRESSOR selector knob to 2. The
sequence of letters and numbers thus se-
f. S e t t h e P O W E R s w i t c h t o t h e O F F p o s i -
listed in the test data book. The selectors are
interconnected electrically so that two differ-
ent voltages cannot be applied to the same
The procedures below apply to single-section
tube pin at the same time. Therefore, acci-
dental shorts are avoided.
and multipurpose tubes (tubes that have more
( 4 ) Set the BIAS control to the number
than one set of elements in the same envelope).
indicated in the B i a s c o l u m n
Test each section or group of elements of a
test data book.
multipurpose tube separately. Test data for the
multipurpose tube types are listed by sections
( 5 ) Set the SHUNT control to the number
indicated in the S h u n t c o l u m n o f t h e
the test data book.
test data book. If no setting is indi-
cated, disregard this step and proceed
C a u t i o n : Do not insert a tube into a test
with the steps below.
socket until all the controls have been set in
( 7 ) Insert the tube to be tested in the