Racal Instruments AN/TRC-207, Operation And Maintenance Instructions

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TO 31R2-2TRC207-1
4-13
4-6 COVERT OPERATIONS
By placing the DISPLAY switch (1, Figure 4-1) in the OFF position, all
LEDs on the front panel of the bi-directional repeater are disabled to allow light discipline in blackout conditions. The
frame cover is used to further conceal the BDR. Turning off the LEDs also helps to conserve battery power.
4-7 RECEIVER-TRANSMITTERS
For operating procedures for the receiver-transmitters, refer to TO 31R2-2PRC139-1. Ensure that the MODE switch on
both radios is set to CLR and the SCAN switch is OFF. Disregard operating procedures for secure mode.
4-8 EQUIPMENT SHUTDOWN
Shut down the bi-directional repeater as follows:
a. Place the AC/DC POWER switch (1, Figure 4-2) in the OFF position.
b. Verify that the BDR is off by confirming that the POWER LED is not illuminated when the DISPLAY
switch (1, Figure 4-1) is in the ON position.
c. Emergency shutdown can be accomplished by setting the power supply circuit breakers switches (1 and
2, Figure 4-3) to the FAULT/OFF position.
Section III. EMERGENCY OPERATION
4-9 EMERGENCY POWER
The bi-directional repeater can be powered directly from a battery installed in a vehicle for external power. Use the DC
power supply cable assembly (SS-4500109-501) with the positive cable lug connected to the positive battery terminal and
the negative cable lug grounded to the vehicle frame.
4-10 ELECTROMAGNETIC PULSE PROTECTION
Electromagnetic Pulse (EMP) is a pulse of broad bandwidth, high amplitude radio frequency electromagnetic energy
produced by the radiation from a nuclear burst.
4-10.1 EMP Susceptibility
EMP can deliver a power density to a radio receiver a billion times greater than the power necessary for reception. The
voltage and current surges resulting from EMP can overload most modern solid state electronic devices.
4-10.2 EMP Protective Measures
All equipment not absolutely required in primary systems should remain disconnected and stored within a sealed shelter
or other shielded enclosure for protection from EMP. At a minimum, equipment not required should be turned off. To
prevent or reduce "coupling" with the energy from EMP, wires and cables (to include output coaxial types) should be
shielded and properly grounded. Lengths of cables should be kept as short as possible. Excess lengths of cable in use
should never be left wound on a cable reel but should be pulled out in a straight line to avoid having loops in the cables.
When cables are not needed, they should not be connected to the equipment. Burying cables a foot or more will reduce
their exposure to EMP fields. Antennas and their connecting cables should be disconnected from radio sets when not in
use. Narrow bandwidth antennas requiring high power for operation reduce the EMP coupling effect.