TM 11-6625-1633-45
(2) Carefully sketch or tag the connections to the
a. Removal of Low Frequency Travel Stop Screw.
two switches and unsolder them.
(1) Remove the rf oscillator section (para 4-2).
(3) Remove the two mounting screws through the
(2) Remove the POWER SET and ATTENUA-
top of switch A4S2 and remove the two switches.
TOR control knob by loosening the set screws and pull-
ing the knobs away from the front panel.
b. Replace the microswitch as follows:
(3) Remove the -center frequency selector hand-
(1) Replace the defective microswitch and mount
wheel by loosening the two set screws and pulling the
the two switches by means of the two mounting screws.
handwheel away from the front panel.
(2) Solder the connections indicated by the tags or
NOTE
sketch made in a (2) above.
To make these set screws accessible it may
(3) Loosen the binding head screw on the at-
be necessary to adjust the handwheel until
tenuator closest to switch A4S1.
the 600-1850 MC FREQUENCY MC
counter indicates 592 MHz. Then slip the
(4) Rotate the counter frequency selector hand-
clutch inside the handwheel until the set
wheel for a frequency indication of 845 MHz.
screws become accessible. The clutch is
slipped by continuing the rotation of the
(5) Loosen the second binding head screw on the
handwheel after the stop is reached.
attenuator cam and adjust the cam to just trip switch
A4S1.
(4) Remove the three binding head screws holding
(6) Tighten the second binding head screw.
the rf oscillator section front panel.
(7) Rotate the center frequency selector hand-
(5) Remove the rf oscillator section front
wheel for a frequency indication of 600 MHz.
(6) Loosen the low frequency stop screw locknut
(8) Tighten the first binding head screw.
and remove the stop screw.
(9) Check that switch A4S1 is activated between
b. Replacement of Low Frequency Travel Stop
840 and 845 MHz.
Screw.
(10) Loosen the binding head screws on the mode
(1) Temporarily reassemble the center frequency
cam.
selector handwheel and tighten the set screws.
(11) Rotate the center frequency selector handwheel
for a frequency indication of 1067 MHz.
(2) Rotate the center frequency selector hand-
wheel for a frequency indication of 592 MHz.
(12) Adjust the mode cam to just trip switch A4S2.
(3) Insert the stop screw, lockwasher and locknut
(13) Tighten the binding head screws.
until the screw is stopped by the carriage.
(14) Check that switch A4S2 is activated between
(4) Tighten the locknut.
1065 and 1070 MHz.
(5) Remove the center frequency selector hand-
4-8. Replacement of Tape Cam
wheel.
A worn tape cam may be replaced by removing the
screw at one end and unhooking the spring at the other.
(6) Reassemble the rf oscillator section front panel
The replacement is fastened by hooking the spring to
and tighten the three binding head screws.
one end of the tape cam and screwing down the other
end.
CAUTION
Make sure that the three shafts are free to
4-9. Replacement of Frequency Travel
rotate.
Stop Screws
(7) Reassemble the two knobs and the hand
The low and high frequency travel stop screws are
shown in figure 3-6. To replace either stop screw, pro-
c. Removal of High Frequency Travel Stop Screw.
ceed as follows:
4-4
