TM 1-1520-238-10
3-23
3.8.2 Operating Procedures.
a. Preliminary Operation.
NOTE
Before the pilot VHF-FM radio may be oper-
ated in ciphered (secure voice) mode, it
must be loaded with one or more (CNVs).
Refer to TM 11-5810-262-12&P for com-
plete details on loading these variables.
1. KY-58 POWER switch – ON.
2. KY-58 MODE switch – C (cipher).
3. KY-58 VOLUME control – As desired.
4. KY-58 Fill switch – Any numbered storage regis-
ter position (1-6).
5. Power Interface Adapter 4 – Position switch to
BBV.
6. Power Interface Adapter FILTER selector – IN.
7. RCU DELAY switch – Down (off) position.
8. RCU C/RAD 1-PLAIN switch – C/RAD 1.
9. RCU MODE switch – OP.
10. RCU Fill switch – Set to the proper (CNV).
11. RCU POWER switch – On.
NOTE
At this time you should hear an intermittent
tone and background noise. The back-
ground noise is normal. The tone is a crypto
alarm that must be cleared before the radio
can be used. If step 12 does not clear the in-
termittent tone, double check steps 1
through 11. If necessary, refer to
TM 11-5810-262-12&P.
12. RADIO/ICS switch – RADIO press and release
(or the pilot push-to-talk floor switch). This
should clear the crypto alarm.
b. Cipher Mode.
1. After steps 1 through 12 are complete, the radio
is ready to transmit and receive secure speech
in ciphered mode.
2. To transmit, press any push-to-talk switch. You
may begin speaking following the beep.
c. Plain Mode.
1. C/RAD 1/PLAIN – PLAIN.
2. To transmit, press any push-to-talk switch. You
may begin speaking immediately.
d. Automatic Remote Keying (AK).
NOTE
AK causes an old CNV in one of the regis-
ters to be replaced by a new one, or an
empty register to be filled. Your net control-
ler simply transmits the new CNV to your
TSEC/KY-58.
1. Your net controller will contact you by using a se-
cure voice channel, and tell you to wait for an AK
transmission. You must not transmit during this
period.
2. You will hear one or two beeps in your headset
when the AK occurs.
e. Manual Remote Keying (MK).
NOTE
MK requires you to use the RCU to change
CNVs.
1. The net controller will contact you by using a se-
cure voice channel. He will tell you to stand by
for a new or replacement CNV and that you will
use an MK action.
2. Fill switch – 6. Notify the net controller by radio
when you have done this and stand by.
3. The net controller will tell you to set the MODE
switch to RV. Notify the net controller when you
have done this and stand by.
4. When notified by the net controller, set the fill
switch to the storage position selected to receive
the CNV. Notify the net controller when you have
done this and stand by.
