Alignment Chart, Receiving Set, Radio AN/PRR-9(XE-9)

o. Replace the AN/PRR-9 (XE-9) electronic assembly in its case (TM 11-5820-549-12-1). Tighten the two retaining

screws on the AN/ PRR-9(XE-9) front plate and install the screw holding the horn transducer to the AN/PRR- 9(XE-9)

electronic unit assembly. Replace the AN/PRR-9(XE-9) Battery BA4534/U. Attach the AN/PRR-9(XE-9) to a helmet and

place the helmet on the operators head. The antenna should be vertical with respect to the ground. Turn the AN/PRR-

9(XE-9) receiver control fully clockwise, for unsquelched opera- tion then counterclockwise for a comfortable listening

level.

p. Remove the P12 receiver antenna connector (fig. 313) from the ID-1189(XE-2)/PR RCVR ANT. receptacle (fig. 3-

12). Remove the test antenna (fig. 1-1.1) from the ID-1189 (XE-2)/PR lid and plug it into the ID-1189 (XE-2)/PR RCVR

ANT. receptacle. Set the ID-1189 (XE-2) /PR FUNCTION switch to RCVR ANT.

q. Position the operator with the helmet mounted AN/PRR-9(XE-9) from 3 to 4 feet from the ID-1189(XE-2)/PR. Set

the ID-1189 (XE-2)/PR RCVR TEST SIG. rotary switch so that noise is heard in the receiver horn transducer.

r. Adjust the AN/PRR-9(XE-9) antenna loading coil (fig. 3-8) for minimum noise. Vary the distance of the AN/PRR-

9(XE-9) from the ID-1189(XE-2)/PR or adjust the RCVR TEST SIG. rotary switch to maintain some noise in the AN/PRR-

9(XE-9). Repeat the adjustment of the antenna loading coil until no further reduction of noise can be obtained.

s. Remove the AN/PRR-9(XE-9) from the helmet, turn the receiver control to OFF, and mark the operating frequency

in the space provided on the AN/PRR-9(XE-9) identification plate.

t. Set the ID-1189(XE-2)/PR FUNCTION switch to OFF. This action completes the alignment procedure and the

AN/PRR-9(XE-9) is now ready for use on the selected channel fre- quency.

3-6.3 Alignment Chart, Receiving Set,

Radio AN/PRR-9(XE-9)

After becoming familiar with the procedures in paragraph S6.2, the following alignment chart may be used to permit more

rapid AN/PRR-9(XE-9) alignment. Preliminary procedures require connecting receiver antenna P12 to RCVR ANT

receptacle, TEST PROBE to RECEIVER ALIGNMENT adapter top receptacle, and RCVR OUTPUT plug to RE- CEIVER

ALIGNMENT adapter bottom receptacle.

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