uAvionix echo, Инструкция по установке и руководство пилота

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UAV-1001006-001
ECCN 7A994
7.7 Wiring Considerations
The echoUAT was designed and tested using unshielded, untwisted wiring.
There may, however, be technical benefits of improved electromagnetic
emissions and susceptibility to and from the transponder system. The use
of twisted wire can reduce interference and break-through on adjacent
audio wiring if it is not possible to route them separately.
The distance between the echoUAT and the power source is limited by the
impedance of the wire between them. The echoUAT is powered directly
from aircraft power, and, therefore, the acceptable voltage drop in the
power line is what limits the distance.
A 1A circuit breaker should be used between the echoUAT and the power
source. A 3A gang circuit breaker can be used when echoUAT and
SkyFYX are combined on the same circuit.
The echoUAT requires an impedance of less than 0.5ohm in the power line
for satisfactory operation. The following table provides guidance for a
typical aircraft hook-up wire. Note that different brands may vary
– please
check your supplier for more details.
Gauge ohm/km Length for 0.5ohm
20 AWG 35 14.2m
22 AWG 64 7.8m
24 AWG 99 5.0m
An alternative to a harness built from individual wires, particularly for a long
cable run, is to use a multi-core cable. Aviation grade cables with 6 or more
cores are often more expensive than individual wires, and, therefore, are
not generally a good choice. For aircraft where those situations do not
apply, an attractive alternative solution may be to use 3 or 4 pair data
cable.
Please note that not all data cable is suitable for this application. Cables
with solid cores should not be used. Cables should be selected based on
the wear characteristics of their insulation material, including temperature
rating, resistance to solvents and oils, and flammability. Most inexpensive
commercial data cables have poor flammability properties.