TM 11-5820-890-10-l
JAMMING, Jamming is the intentional transmission of signals that interrupts your
ability to receive needed signals. Interference is the accidental transmission of sig-
nals that also interrupts your ability to receive needed signals. If you are being
jammed, it might sound like strong static, misleading signals, or random noise; or
the net may be quiet with no signals heard. These signals depend upon the type
of jamming signals and whether your net is operating in single channel (SC) or fre-
quency hopping (FH) mode. The source of jamming could be power generators, ra-
dar sets, high power HF radio sets, or intentional enemy jammers. Use the following
table to determine the possible source of jamming and the corrective actions.
SINGLE CHANNEL OPERATIONS.
SYMPTOM
POSSIBILITIES
SIG marker is lit and
(1) You have a bad
showing a signal high-
handset if you dis-
er than LO. You hear
connect the hand-
no traffic or noise and
set and the lighted
you are not transmitting. signal goes away
(stuck or "hot"
mike).
(2) You are being
jammed if you set
RT FCTN switch to
SQ OFF and hear
strong static or ran-
dom noise. You can
confirm this by dis-
connecting the an-
tenna (MP) or an-
tenna cable (vehic-
ular). The SIG mark-
er will drop and the
noise will go away
or be reduced.
(3) You may have a
faulty or "locked-up"
RT if you try remov-
ing the handset and
the antenna (MP) or
antenna cable (vehic-
ular) and the SIG
marker remains high-
er than LO.
ACTION
(1) Try to free-up the stuck
mike by pressing push-to-
talk 2 or 3 times. Remove
faulty handset and replace
with one that is good.
(2) Change your tactical lo-
cation. Try to mask your RT/
antenna by placing hills,
rocks, buildings, etc. be-
tween you and the enemy.
Notify your supervisor and
prepare a MIJI feeder
report.
(3) Set RT FCTN switch to
then to SQ ON. If
problem still exists, contact
unit maintenance.
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