TM 11-6625-3053-14
c.
Turn attenuator control until the 4-40 hex set screw holding the attenuator probe is centered in hole at top of
attenuator probe mounting block.
Loosen this screw and the other 4-40 hex set screw appearing in the slot at the rear of the mounting block.
d. Pull attenuator probe out of drive yoke.
e. Detach P4 from J4. Removal is now complete.
REPLACEMENT
a. Turn attenuator control fully clockwise to its bottom position.
b. Insert replacement attenuator probe straight into the attenuator drive with the ground stub of probe in the
vertical position.
c.
Gently seat the probe until it butts against inner conductor. Then back off about .006 inches or the thickness
of a 34 AWG solid wire.
d. Lock the set screws to secure probe to drive cylinder.
e. Reattach P4 to J4.
f.
Perform Alinement step 7 to calibrate attenuator.
6-36.
REPLACEMENT OF KLYSTRON OSCILLATOR
REMOVAL
a. Remove instrument dust cover (para 6-20).
c.
f.
Turn Power Set drive gear fully clockwise.
g. Loosen attenuator probe drive gear at front of tuning head. Rotate attenuator dial clockwise to retract probe
drive until leading edge enters drive mounting block approximately 5/8 inch.
h. Remove central screw in oscillator yoke disc holding push rod yoke to disc.
i.
Pull yoke/cam follower fully toward front panel and clamp it out of the way to the front panel.
j.
Remove 2 8-32 allen cap screws retaining the 2 oscillator cylinder clamps.
k.
Remove klystron oscillator from seating.
l.
Unsolder red repeller lead on oscillator from terminal A4A1 E7. Remove A4A1 tracking board to accomplish
this. Remove this red lead from harness.
NOTE
In replacing klystron oscillator, resolder red repeller lead to E7 and tie new
lead to existing harness.
REPLACEMENT
a. Reverse the removal procedure through step h above except do not tighten screws in step j above. Then
continue as instructed below.
b. Turn attenuator control clockwise until it reaches limit of its travel.
6-94