23. Removal, Mounting, and Replacement
21. Removal and Replacement of
of Tube Data Roll Chart
Transformers
a. Removal.
(1) Remove the chassis from the case and
lower the chassis (par. 20). Trans-
and should never be lubricated.
f o r m e r s T1 and T2 are mounted
When a new tube test data roll chart is to be
through the chassis (figs. 17, 18, and
installed in the tube tester, follow the instruc-
tions in a through c below.
(2) Disconnect and tag the wiring to the
a. Removal.
terminals of the defective transformer
( 1 ) The tube test data roll chart housing is
o n both the front and rear of the
bolted to two mounting brackets inside
chassis.
the cover of the tube tester (fig. 1, TM
(3) Remove the bolts, the nuts, and the
11-6625-31 612). Remove the tube test
l o c k w a s h e r s that mount the trans-
data roll chart housing by removing
former on the chassis. Pull the defec-
the two bolts, the nuts, and the lock-
tive transformer away from the front
washers that mount the housing to
of the chassis.
these brackets.
b. Replacement.
(2) Remove the three screws that mount
the roller guide plate to the housing.
front of the chassis.
Pull the roller guide plate from the
(2) Replace the bolts, the nuts, and the
housing. Do not loosen the three screws
lockwashers that hold the transformer
that mount the tube test data roll chart
on the chassis.
guide plate to the gear end of the
(3) Connect the transformer wiring to the
housing.
a p p r o p r i a t e terminals on both the
(3) Remove the two rollers by sliding them
front and rear of the chassis as indi-
away from the gear end of the housing.
cated on the tag.
(4) Remove the old tube test data roll
chart and the tape that mounts the tube
22. Removal and Replacement of Resistor
test data roll chart to the rollers. To
Mounting Board
remove any adhesive from the old
mounting tape that may be adhering
Caution: To disconnect wire leads, remove the
to the rollers, clean the rollers with a
resistor mounting board or chassis completely;
cloth dampened with Cleaning Com-
be sure to tag all disconnected leads so that they
pound (Federal stock No. 7930-395-
can be reconnected to the proper terminals when
9542) .
the tube tester is reassembled.
warning: Cleaning compound is flam-
a. Removal.
mable and its fumes are toxic. Do not
use near a flame; provide adequate
(2) Remove the four screws that mount
ventilation.
the resistor mounting board on the
b. Mounting.
chassis mounting brackets.
(1) Unroll 1 foot of the new tube test data
(3) Move the resistor mounting board
roll chart. With the rollers positioned
a w a y from the chassis mounting
as shown in figure 20, place the top of
brackets.
the tube test data roll chart, with the
(4) Move the resistor mounting board for-
printed side upward, parallel to the
ward or backward, as required, as far
guideline marked on the upper roller.
as the wiring will permit.
(2) Use two small tabs of pressure-sensi-
b. Replacement.
tive tape, approximately one-half inch
(1) Move the resistor mounting board for-
long, to anchor the top of the tube test
ward or backward, as required, to line
data roll chart along the guideline.
up the four holes with those on the
(3) Apply pressure-sensitive tape to the
chassis mounting bracket.
entire length of the roller, with half
(2) Replace the four screws.
31
AGO 1428A
