3: Operation
3-6
PRC1077-MSOP
Anti-Jamming
When jamming is first detected, try the following checks to reduce the effects:
Radio Set Compatibility
The PRC1077 can communicate with most frequency-modulated (FM) radio
sets. The PRC1077 is compatible with the AN/PRC77 and PRC28 radio sets,
however, incompatibilities do exist that impose limitations, for example, the
PRC1077 has a higher frequency range and smaller frequency spacing than
the PRC77 and PRC28 radio sets.
Frequency
Range
The PRC1077 has a operational frequency range from 30 MHz to
87.975 MHz whereas the PRC77 transceiver has a frequency range from
30 MHz to 75 MHz, leaving a range of frequencies from 76 MHz to
87.975 MHz that the PRC1077 cannot use when communicating with a
PRC77.
Switch to several
different channels.
If the interference is present on all channels,
interference is from a local noise source.
Action
Indication
Action
Position the PRC1077 to make use of nearby obstructions to act as a screen
against the jamming source. Experiment with different locations as the
interference signal strength may vary substantially over very short
distances.
Operate at the minimum power level that still provides adequate
communications. This makes it difficult for the jamming source to intercept
transmissions and determine the jamming frequency.
Change the channel frequency. With multiple preset channels, the PRC1077
is capable of changing frequencies quickly, so unless the jammer is using
very advanced jamming equipment, it will take some time to find the
operating frequency and resume jamming.
Set up predetermined time slots for communications using specified
channels at specified times, for example, channel 1 used from 00 minutes to
15 minutes past the hour; channel 2 used from 15 minutes to 30 minutes
past the hour; etc.
Set up frequency change schedule. When jamming is detected, operators
switch to the next frequency in the schedule. This arrangement is
particularly effective when only two stations are communicating.
Use split-frequency operation. This configuration uses different transmit
and receive frequencies.