Checks and corrective measures
Check receiver-transmitter and
No guard receiver audio
Defective receiver-transmitter, or
radio set control by substitution;
radio set control.
replace defective unit (paras
3-13 and 317). Higher category
a. Check receiver-transmitter and
a. Defective receiver-transmitter, or
Adf equipment does not
radio set control by substitution
radio set control.
( p a r a s 3-13 and 3-17); replace
defective unit. Higher category
b. Refer to applicable technical
b. Defective adf equipment -------
manual to check operation of adf
safety wires (TM 11-530) between the mount-
Removal and Replacement of Radio
ing and each wingnut fastener.
Set Control Panel Lamps
(3) Connect the antenna and the power
( C - 1 6 7 7 / A R C - 5 1 X Only)
and control cables.
a. Turn each lampholder (fig. 2-1) counter-
3-14. Removal and Replacement of
clockwise to unscrew it from the front panel
External Blower Air Filter and Fuse F1
of the radio set control.
b. Extract the lamp from the lampholder
with the thumb and forefinger; pull straight
(1) R e m o v e t h e
from the mounting (para 3-13) to reach the
c. Insert a new lamp into the lampholder
by pressing on the contact end.
(2) Loosen the two knurled thumbscrews
d. Replace the lampholder on the front panel
and remove the air filter from the external
by screwing it into the socket in a clockwise
direction; tighten securely.
(3) Remove l-ampere fuse F1 from the air
3-13. Removal and Replacement of
(1) Replace fuse F1 in the air filter holder.
(2) Replace the air filter and tighten the
thumbscrews on the top of the air filter.
(1) Disconnect the antenna and the
(3) Replace the receiver-transmitter on the
power and control cables from the receiver-
mounting (para 3-13b).
(2) Remove the safety wires (not shown)
3-15. Removal and Replacement of
from the wingnut fasteners on the mounting
base. Loosen the wingnut fasteners and swivel
them upward to disengage the latches on the
(1) Remove the receiver-transmitter from
the mounting (para 3-13) to reach the external
(3) Grasp both handles on the receiver-
transmitter dust cover and slide the unit off
(2) Use a No. 6 Allen wrench to loosen
the four captive retaining screws which fasten
the external blower to the receiver-transmitter
(1) Slide the receiver-transmitter onto
(3) Pull the external blower away from
(2) Swivel the wingnut fasteners down-
the receiver-transmitter to disconnect the ex-
ward to engage the latches on the mounting.
ternal blower connector (not shown) from the
Tighten the wingnut fasteners, and secure the