TM 11-6625-1559-12
Sequence
No.
Procedure
References
Item to be inspected
c. If the 1-MHz markers are not visible or if
chassis, so that none 1-MHz markers appear
between any pair of 10-MHZ markers.
d. Set the SWEEP WIDTH switch to NARROW
and check the range of the SWEEP WIDTH
control; use the 1-MHz markers. The range
should be from 10 kHz to 1 MHz.
Uhf output level check ----- a. Zero the VOLTS meter with the PULL TURN
9- - - -
FOR ZERO control.
switch to OFF.
c. Turn the RF OUTPUT control ccw until
begins to flatten.
d. Check to see that the reading on the UHF
scale of the VOLTS meter is 0.5 volt rms
or more.
10---
Vhf SWEED WIDTH
a. Set the BAND SELECTOR switch to VHF
range check.
and the ATTENUATOR db switch to 0.
b. Set the SWEEP WIDTH control for
maximum sweep width and adjust phasing.
c. Set the RF OUTPUT control fully clockwise;
then slowly turn it counterclockwise until
the response trace flattens.
d. Check the range of the SWEEP WIDTH
control. It should be from 10 kHz to 1 MHz.
e. Pull the 100 MHz MARKER GAIN switch.
adjust the FIXED OSC FREQ control so
that the 100-MHz marker is just off the
center of the zero beat.
g. Set the SWEEP WIDTH switch to WIDE
and adjust the SWEEP WIDTH control
for maximum sweep width.
h. Tune the sweep
generator to
position the
zero
beat at the extreme left of the display.
i. Set the RF OUTPUT control fully clockwise,
then slowly turn it counterclockwise until
the trace flattens.
j. Use the 100-MHz markers, and verify that the
sweep width is at least 400 MHz.
Vhf output level check ---- a. Zero the VOLTS meter with the PULL TURN
11----
FOR ZERO control.
switch to OFF.
c. Turn RF OUTPUT control ccw until the
begins to flatten.
d. Check to see that the reading on the VHF
scale of the VOLTS meter is 0.25 volt rms
or more.
4-5. Weekly Preventive Maintenance Checks and Services Chart
Sequence
No.
Item to be inspected
Procedure
1 ----
Power cord -------- Inspect the power cord for chafed, cracked, or frayed insulation. Replace connectors
that are broken, arced, stripped, or worn excessively.
2 -----
Handles ----- Inspect handles for looseness. Replace or tighten as necessary.