(c) Turn variable resistor R1502 (18) fully
by removing screws (4).
ccw.
(5) Place C-band connector bracket assembly (5)
(d) Set dials of counter assembly (19) to low
on the adjacent work surface so that back of connector
and back of dispersion PC board assembly (refer to 1,
end of frequency band.
(e) Install gear (17) on counter assembly
further disassembly.
(19) shaft and engage with gear (16). Do not tighten
(6) Unsolder and remove red harness lead from
setscrew.
terminal 2 of dispersion PC board assembly (refer to 1,
(f) Install gear (16) on the shaft of variable
resistor (18). Do not tighten setscrew.
(7) Remove male connector contacts 7, 16, and
(g) Check counter setting and position of
19 (refer to 13, fig. 4-23) from C-band connector (refer
variable resistor (18). Both settings must be as specified
to 10, fig. 4-23). Follow applicable procedures outlined
in (c) and (d) above.
(h) Secure gears to respective shafts with
in g (1) below.
(8) Remove four screws (13, fig. 4-20) from C-
setscrews.
band BWO tube (12) support brackets.
(9) Disconnect coaxial cable connector from C-
4-20. Disassembly and Assembly of C- and
band directional coupler (14) and remove BWO tube
X-Band Rf Head
(12).
To disassemble the C- and X-band rf head, refer to
b. Removal of X-band BWO Tube 7923110.
exploded view, figure 4-20, and appropriate wiring
Before removing BWO tube, read and observe all
diagram, figure 4-21 or 4-22, and follow procedures a
instructions appearing on the tube and rf head case.
through f below.
Since BWO tube emanates strong magnetic fields, all
a. Removal of C-Band BWO Tube 7923109.
work must be performed in a location free from possible
Before removing BWO tube, read and observe all
magnetic fields. Work surfaces and tools must be non-
instructions appearing on the tube and rf head case.
magnetic. Refer to exploded view, figure 4-20, and
Since BWO tube emanates strong magnetic fields, all
wiring diagram, figure 4-22. Remove tube as follows:
work must be performed in a location free from possible
Caution. Exercise extreme care when removing
magnetic fields. Work surfaces and tools must be non-
BWO tube to avoid damage to adjacent and related
magnetic. Refer to exploded view, figure 4-20, and
electronic, electrical and mechanical components
wiring diagram, figure 4-21. Remove tube as follows:
and assemblies.
Caution. Exercise extreme care when removing
(1) Remove left side cover (1, fig. 4-20) by
removing 10 screws (2) attaching it to rf head chassis
BWO tube to avoid damage to adjacent and related
(42).
electronic, electrical and mechanical components
Caution. The soldering iron should be pencil
and assemblies.
type, 15 watts or less, and connected through a
thermostatically controlled soldering iron stand.
(1) Remove left side cover (1, figure 4-20) by
Apply soldering iron so that it touches only the
removing screws (2) attaching it to rf head chassis (42).
solder point.
Caution. The soldering iron should be pencil
(2) Unsolder and remove green, orange, and
blue harness leads from X-band connector bracket
type, 15 watts or less, and connected through a
assembly (3) solder lug (refer to 16, fig. 4-23).
thermostatically controlled soldering iron stand.
(3) Remove clamp (6, fig. 4-20) by removing
Apply soldering iron so that it touches only the
hex nut (7), lockwasher (8), flatwasher (9), and screw
solder point.
(4).
(4) Free X-band connector bracket assembly (3)
by removing screws (4).
harness leads from C-band connector bracket assembly
(5) Place X-band connector bracket assembly
(5) solder lug (refer to 16, fig. 4-23).
(3) on the adjacent work surface so that back of
(3) Remove clamp (6, fig. 4-20) by removing hex
connector and back of dispersion PC board assembly
nut (7) lockwasher (8), flat washer (9), and screw (4).
(refer
to
1,
are
(4) Free C-band connector bracket assembly (5)
4-30
