Cables should be separated and routed to take
advantage of any inherent shielding effectiveness of the airframe, bulkheads
and other cables. In this way interference coupling will be reduced between
cables and between cables and the external environment.
Once the cables' E3 categories have been identified, the cable
runs must be designed to preclude coupling between interfering cables and
susceptible cables and wiring. This can be accomplished wherever space allows.
However, in tight situations where adequate separation is not practical, other
methods should be used to eliminate interference coupling. These alternative
methods might include the use of shielding, fiber optic cables or installation
of filters where possible.
Wiring, including RF and antenna cables, should be routed to minimize EMI.
A sample segregation scheme is depicted in Table 4-3.
Figure 4-l0 shows an example of E3 cable separation and routing.
The cables depicted are routed on the overhead, with the picture shown looking
forward on the aircraft. The cables along the starboard side, designated "EV-6,"
are high power RF or pulse cables. Those designated "EV-4" and "EV-8" are lower
power RF cables; while the cables on the port side designated "EV 9-12" are
control cables, audio frequency cables and DC power cables. This arrangement
puts the most difficult cables along the starboard side while the less
problematic cables are separated on the port side. The most sensitive cables are
not run in the overhead, but are situated farthest away along the port side of