TM 11-6625-1559-12
Sequence
No.
Item to be inspected
Procedure
References
Connectors - - - - - - - - - - - - - - - - Check the tightness of all connectors.
3----
Controls and indicators - - - --- While making the operating checks, observe that
4------
the mechanical action of each knob, dial, and
switch is smooth and free of external or
internal binding, and no excessive looseness
exists. Also, check the meter for sticking or
bent pointers.
5 ----
Preliminary - - - - - - - - - - - - -a. Set the controls as follows:
(1) POWER switch to OFF.
(2) PREAMPLIFIER controls:
AC-DC switch: DC.
BALANCE control: midrange.
GAIN control: fully ccw.
(3) BAND SELECTOR switch: UHF.
(4) SWEEP WIDTH switch: WIDE.
(5) SWEEP WIDTH control: fully cw.
(6) RF OUTPUT control: fully cw.
(7) ATTENUATOR db switch: 20.
b. Insert shorting plug into EXT WOBB DRIVE
socket on rear panel of main chassis.
c. Connect only the horizontal input to the
oscilloscope.
6----
POWER switch - - - - - - - - - - -.. Set the POWER switch to ON, and turn on
7-----
PREAMPLIFIER DC
a. Set oscilloscope vertical sensitivity to 0.1
volt per centimeter and horizontal
LEVEL and BALANCE
controls.
sensitivity to 2 volts/cm. Center trace on
screen.
b. Connect the SCOPE VERT jack to the dc-
coupled vertical input of the oscilloscope.
If the trace disappears, return it to the
reference line by adjusting the PRE-
AMPLIFIER DC LEVEL control.
fully clockwise. If the trace moves, return
it to the reference line by adjusting the
coarse preamplifier balance potentiometer
(screwdriver adjustment accessible through
the center of the PREAMPLIFIER
BALANCE control knob).
fully counterclockwise. If the trace moves,
return it to the reference by adjusting the
PREAMPLIFIER DC LEVEL control.
e. Repeat the instructions in c and d above
until the PREAMPLIFIER GAIN control
can be rotated throughout its entire range
without changing the position of the trace
by more than 2 cm. Use the front panel
PREAMPLIFIER BALANCE (fine) con-
trol for finer adjustment.
vertical input. If the trace moves, adjust
the PREAMPLIFIER DC LEVEL control
unitl the trace remains in position whether
or not the vertical input connection is
made.
8----
a. Reconnect the oscilloscope vertical input
Uhf SWEEP WIDTH
b. Use the 1-, 10-, and 100-MHz markers, and
range check.
check the range of the SWEEP WIDTH
control. It should be at least from 500
4-2