TM 1-1520-240-MTF
4-64
15. HF Radio (AN/ARC-220)/COMSEC (KY-100).
a. AN/ARC-200 Function switch T/R. Mode
switch PRE and Channel selector
Appropriate preset (1-20) containing a
frequency to transmit /receive in USB.
b. KY-100 Mode switch PT. Preset
Desired position for plaintext operation.
Plaintext beeps are heard when system is
idle or receiving.
c. Transmit/Receive
and
evaluate
communications throughout a 360 degree
turn.
d. Repeat
the
process
with
ARC-220
operating on LSB, AME and CW.
e. KY-100 Mode switch CT, Preset
Desired position for ciphertext operation.
f. Transmit/Receive with ARC-220 operating
on LSB, AME or CW.
g. ARC-220 Mode switch ALE,SQL
switch 0 or 1.
h. Push PTT.
i. ARC-220 displays CALLING
j. Wait for a short gong tone and LINKED on
display before transmitting to a like
configured station.
k. ARC-220 Mode switch ECCM.
Channel switch Desired channel, SQL
switch 0 or 1.
l. Transmit to a like station by pressing PTT,
wait for preamble tones to cease and begin
transmission.