TM 55-1510-215-MTF
PROCEDURE
TROUBLESHOOTING
REFERENCE
DURING CRUISE (CONT)
j. When possible, check selective address
(transmit and receive) operating mode.
*16. HF voice security mode (TSEC/ KY-75) - Check
as follows:
a. Ensure HF radio set is operable (15.
above).
b. PLAIN/CIPHER switch (TSEC/ KY-75
control) - CIPHER.
c. RMT/LOCAL/SIG CLR switch - RMT.
d. PWR/FILL switch - Set to desired fill
register.
e. Secure voice (SV-DATA) mode (HF radio
set) - Select as required.
f. Microphone switch - Press. Wait for the
preamble to stop, then talk into the
microphone.
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