TM 55-1680-351-10
d.
Check for presence of earphone and check earphone case and
cover.
e.
If deviations are noted, take required corrective action.
f.
Replace antenna in stored position, replace in normal stowage
or flight suit in accordance with latest directives.
32.
Modes of Operation
a.
General. Radio Set AN/PRC-90 will be used only for
emergency (and/or tactical) communications.
The radio can be expected to perform properly, assuming normal
maintenance has been kept current.
b.
Operational Modes.
The following operational modes are available:
(1)
Beacon mode. Used initially on 243.0 MHz.
(2)
MCW
mode.
Used
for
transmitting
modulated
continuous wave codes (MCW) as required on 243.0 MHz.
(3)
Voice
mode.
Used
for
two-way
transceive
communication with air, sea, or ground radios on 243.0 MHz. 282.8 MHz
can be used as an alternate voice channel as directed.
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