Microair Avionics
T2000UAV-L
Install and User Manual
T2000UAV-L Installation and User Manual 01R1.doc
Page 12 of 24
28
th
July 2009
6.0
ANTENNA
Mount the transponder antenna as per the manufacturer’s installation instructions. Try and keep the cable runs as
short as possible. In a composite airframe a suitable ground plane will be required. Avoid mounting the antenna
inside a fuselage that is all metal or carbon fibre.
For fiberglass fuselages the antenna may be mounted internally, but must still point downwards and have an
adequate ground plane. Alternatively an approved dipole strip antenna may be used. The dipole strip must be
installed in accordance with the manufacturer’s instructions.
To avoid possible interference the antenna must be mounted a minimum of 200mm (8 inches) from the
T2000UAV-L
main unit. The transponder antenna should be mounted 2metres (78 inches) from the
DME
antenna, 1.5 metres (58 inches) from the
ADF
sense antenna, and 1metre (39 inches) from
TCAS
antennas.
7.0
COAXIAL CABLE
The T2000UAV-L allows for 1.5dB cable loss from the unit to the antenna. The installer should consider
carefully what type of coaxial cable is to be used, so that this loss limit is not exceeded. The cable should be
terminated with silver plated BNC connectors where possible.
Microair recommends the following:
Cable
Bending Radius
Loss @ 1Ghz
dB/m
Max Length
TX Power
RX Sensitivity
RG58/C/U
(Mil Spec)
50mm
(2”)
0.76dB/m
0.21dB/ft
2.0m
7ft
142W -70dBm
RG213/A/U
(Mil Spec)
125mm
(5”)
0.26dB/m
0.08dB/ft
5.75m
19ft
142W -70dBm
RG223/U
(Mil Spec)
100mm
(4”)
0.47dB/m
0.14dB/ft
3.2m
10ft
142W -70dBm
RG400
(Mil Spec)
50mm
(2”)
0.60dB/m
0.18dB/ft
2.5m
8ft
142W -70dBm
Belden 8262
50mm
(2”)
0.68dB/m
0.21dB/ft
2.2m
7ft
142W -70dBm
URM-43 50mm
(2”)
0.47dB/m
0.14dB/ft
3.2m
10ft
142W -70dBm
The loss figures in this table are a guideline only. When installed the power output at the antenna shall be
greater than 125W and receiver sensitivity shall be better than -68dBm, to be compliant with RTCA/DO-144A.
IMPORTANT NOTE
Do not exceed the minimum bending radius. Tight bends will introduce
losses in the cable, which may affect the performance of the transponder.
When fixing the coax cable in the airframe, do not “strangle” the cable
with tight cable ties. This can distort or damage the coax screen.
