TM 9-4935-294-15/2
(h) Secure gears to respective shafts with
4.
Re-seal connector with encapsulating
setscrews.
compound 7919870.
Apply with a brush around all
contacts as required. Cure at room temperature.
4-21.
Disassembly and Assembly of U-Band Rf
(b) Switch stop (interlock) adjustment. To adjust
Head.
connector bracket assembly switch stop, proceed as
To disassemble the U-band rf head, refer to exploded
follows:
view, figure 4-25, and wiring diagram, figure 4-26, and
1. Free switch stop (17, fig. 4-23) by
follow procedures a through d below.
loosening two screws (2).
a. Removal of BWO Tube 7923111. Before
2. Position switch stop (17) so that the
distance from tip of switch stop (17) to edge of chassis
removing BWO tube, read and observe all instructions
is 1.050 +0.000,-0.020 inches.
appearing on the tube and rf head case. Since BWO
Note. Use a jig of local manufacture to establish
tube emanates strong magnetic fields, all work must be
this clearance.
performed in a location free from possible magnetic
3. Secure switch stop (17) in this position by
fields. Work surfaces and tools must be non-magnetic.
tightening screws (2), then seal screw heads with
Refer to exploded view, figure 4-25, and wiring diagram,
sealing compound 10528558.
h. Disassembly and Assembly of the C- and X-
Band Counter Assemblies.
Caution.
Exercise extreme care when
(1) Disassembly. To disassemble the counter
removing BWO tube to avoid damage to
assemblies, refer to exploded view, figure 4-24, and
adjacent and related electronic, electrical
appropriate wiring diagram, figure 4-21 or 4-22.
and
mechanical
components
and
(2) Assembly. To assemble the C- and X-band
assemblies.
counter assemblies, refer to exploded view, figure 4-24,
and appropriate wiring diagram, figure 4-21 or P22, and
(1) Remove left side cover (1, fig. 4-25) by
reverse the order of disassembly. Observe the following
removing 10 screws (2) attaching it to rf head chassis
procedures:
(39).
(a) Cement counter window (23, figure 4-4)
Caution. The soldering iron used should be
to counter assembly (19) with type III, MIL-E-5092A
pencil type, 15 watts or less, connected
adhesive.
through a thermostatically controlled stand.
(b) Obtain gears (16) and (17). If they are
Apply soldering iron so that it touches
replacements, ascertain that they are the proper parts
solder point only.
and have been inspected.
(2) Unsolder and remove the green, orange,
(c) Turn variable resistor R1502 (18) fully ccw.
and blue harness leads from connector bracket
(d) Set dials of counter assembly (19) to low
assembly (3) solder lug (refer to 17, fig. 4-12).
end of frequency band.
(3) Free connector bracket assembly (3, fig.
(e) Install gear (17) on counter assembly (19)
shaft and engage with gear (16). Do not tighten
(4) Place connector bracket assembly (3) on
setscrew.
the adjacent work surface so that back of connector and
(f) Install gear (16) on the shaft of variable
back of dispersion PC board assembly (refer to 1, fig.
resistor (18). Do not tighten setscrew.
(g) Check counter setting and position of
further disassembly.
variable resistor (18). Both settings must be as specified
in
(c)
and
(d)
above.
from terminal 2 on dispersion PC board assembly (1, fig.
(6) Remove male connector contacts 7, 16,
and 19 (refer to 13, fig. 4-12) from connector
Change 1 4-41
