Section IV. OPERATION UNDER USUAL CONDITIONS
Note. To start the equipment, first make sure the controls are set as
required by the preliminary starting procedure (par. 15) and then perform
procedures described in a through i below.
a. Locate the type number of the tube to be tested on the tube
test data roll chart mounted inside the cover of the tube tester.
b. S e t t h e s e v e n S E L E C T O R S s w i t c h e s t o t h e p o s i t i o n s g i v e n
on the tube test data roll chart for the tube under test. Set the
s w i t c h e s in the order in which they appear on the tube test data
r o l l chart and on the tube tester panel, from left to right, starting
with the FIL-SELECTORS switch on the left-hand side.
Note. The seven SELECTORS switches are interconnected electrically so
that two different voltages cannot be applied to the same pin of the tube
under test at the same time. Thus, by setting the SELECTORS switches
in the order in which the switches are arranged on the panel, short circuits
are avoided.
C . Set the FILAMENT RANGE switch to the position indi-
c a t e d on the tube test data roll chart.
d. Insert the tube to be tested into the proper test socket.
Caution: Be careful when inserting and removing loctal, acorn,
a n d subminiature tubes from their sockets. Excessive force will
c r a c k the glass seals at the bases of the pins. Exert slight pres-
s u r e to one side to release the lock of the LOCTAL socket. Use
t h e pin straighteners mounted on the tube test data roll chart
h o u s i n g to straighten bent pins of seven- and nine-pin miniature
tubes.
e. If the tube to be tested has a top cap, attach the A or B
e l e c t r i c a l clip. Directions as to which clip to use are given in the
N O T E S column on the tube test data roll chart unless the NOTES
column is required for other data. In addition, one of the SE-
LECTORS switches will indicate an A or B position. If the A
p o s i t i o n is designated, use the A clip; if the B position is desig-
nated, use the B clip.
f. S e t t h e O N - O F F s w i t c h t o t h e O N p o s i t i o n . T h e P I L O T
l a m p should g1ow. Allow at least 1 minute warmup time.
g. A d j u s t t h e F I L A M E N T f i n e c o n t r o l u n t i l t h e F I L A M E N T
VOLTS meter pointer indicates the exact filament voltages speci-
f i e d in the RANGE column of the tube test data roll chart unless
t h e r e is a note to the contrary. In the case of a filament voltage
o f 0.625, 6.3, 12.6, or 117 volts, adjust the control until the meter
pointer is on the red calibration line on the appropriate scale.
h. If the line voltage is low, it may not be possible to adjust
t h e F I L A M E N T f i n e c o n t r o l t o i n d i c a t e t h e specified filament
voltage. W h e n t h i s c o n d i t i o n e x i s t s , t u r n t h e F I L A M E N T
