JAMMING AND ANTIJAMMING
SINCGARS is jam-resistant due to its frequency hopping capability. Also, hopsets
have been designed to reduce the effects of jamming. However, in the event that
SINCGARS is jammed, it may be necessary for you to take corrective actions. The
action you take depends on the type of jamming or interference that is disrupting
net communication as well as the authorized FH hopset that is available to your
net. A table is provided for the operator on pages 2-47 thru 2-50 that lists symptoms,
possiblities, and corrective actions to be taken.
Keep it simple. If possible, make no changes to communication during en-
gagement or hostile action. In a hostile battlefield environment the enemy may
employ electronic warfare Electronic Countermeasures (ECM) techniques in
an attempt to halt or disrupt your communications. You must be able to identify
jamming techniques and know how to counter them when necessary.
The simplist method the enemy can utilize to disrupt your communication is to trans-
mit noise or audio signals on your single channel operating frequency, or on multiple
FH frequencies during FH operation. If the enemy can generate enough power on
your hopset, it is possible that your communication capability will be disrupted or
even stopped. One of your most difficult tasks is to identify jamming signals. Refer
to the following procedures when a member reports jamming problems or when you
determine you are being jammed. Different jamming situations require different anti-
SITUATION: Your net has been operational and communications has been good with
all stations. The next time stations report, you suddenly receive a great deal of noise
and are unable to hear several of net members. You receive noise even though no
real communication is occurring: a nearby member reports noise reception. You are
probably being jammed. Perform the following steps to confirm and counter jam-
Disconnect antenna. This determines if the noise is internal or external to your
radio. If the noise continues, your radio may be faulty.
Check power supply, RT and antenna ground. A bad ground can conduct noise
into the RT.
Move or reposition the antenna. If communications improve, you probably
are not being jammed.
Notify your supervisor of suspected jamming signals.
Increase RF power.
CONTINUE TO OPERATE! Do not discuss the jamming problem over the air.
Increase antenna height.
Update the net. Changing the hopset may eliminate disruptions.
SITUATION: The enemy may employ what is referred to as subtle jamming. Subtle
jamming is more difficult to detect than noise-generated signals. You will not hear
any noise or incoming signals and even though everything seems to be normal, com-
munication is disrupted. Follow the same antijamming procedures listed above.
Again, CONTINUE TO OPERATE and DO NOT discuss suspected jamming over the
air. Begin antijamming as SOP dictates.