Model 618B Sect. IV Page 1
SECTION IV
MAINTENANCE
NOTE
Constant ventilation is required for cooling the klystron when the instrument is in
operation. Inadequate ventilation resulting either from an ineffective blower motor
or from a clogged air filter can reduce klystron life.
Inspect the air filter and the blower motor regularly. If the instrument is operated
continuously or in dusty areas, the filter should be inspected at least once a month
and replaced if necessary. The condition of the blower motor should be checked
more frequently for overheating, excessive bearing noise, and other signs of re-
duced speed or inadequate air handling capacity. A poor blower motor should be
replaced.
4-1 I NTRO DU CT IO N 4-15 Power Monitor Probe Assembly
4-16 Checking and Trouble Shooting the
This section contains instructions for maintaining, Pulser Section
trouble shooting, replacing tubes, and internal ad- 4-17 Calibrating the Pulse Rate Dial
justing of the Model 618B SHF Signal Generator. 4-18 Calibrating the Pulse Delay Dial
A special systematic trouble shooting procedure 4-19 Calibrating the Pulse Width Dial
tests the complete signal generator in a manner 4-20 Lubrication
that localizes most troubles which may occur. 4-21 Replacing Reflector Potentiometer R174
A chart includes instructions for tube replacement
and subsequent adjustments. It is keyed with ap-
plicable paragraphs in the test to facilitate testing.
The following inforMation can be found in this
section.
4-2 CABINET REMOVAL
4-2 Cabinet Removal To remove the 618B from its cabinet, proceed as
4-3 Blower System follows:
4-4 Visual Inspection
4-5 Test Equipment Required DANGER - 1000 to 1500 volt potentials from very
4-6 Tube Replacement Chart low impedance sources are used throughout the cir-
4-7 Trouble Localization cuits of the signal generator. Bevewcareful when
4-8 Trouble Shooting the Power Supply Section handling the generator with the cabinet removed.
4-9 Checking and Trouble Shooting the RF
Generator Section
4-10 Klystron Removal V114 1) Place instrument panel down on a low surface
4-11 Klystron Replacement so that it rests on the guard rail handles.
4-12 Adjustments Following Replacement of
Klystron V114
,4-13 Calibrating the Frequency Dial 2) Loosen the four captive screws in the rear of
4-14 Replacing and Recalibrating the Attenwtor the cabinet and lift cabinet off the chassis. |