User's Manual Part 1

T
2
CAS / Part No. 9000000
SYSTEM DESCRIPTION AND INSTALLATION MANUAL
34-43-20
15 Feb 2003
Use or disclosure of information on this page is subject to the restrictions in the proprietary notice of this document.
2--3
The d irectional antenna must be separated by a least 30-- inches from any other
L--band antenna, and 60--inches is preferred. If a bottom directional antenna is used,
it should be the most forward antenna on the fuselage bottom with tilt angle
allowances the same as for a top mounted antenna.
An O--ring (included with the directional antenna) is required to be installed between
the directional antenna and the aircraft fuselage. The Navy Aeronautical Standard
part number for the O--ring is NAS 1611--240. The ACSS part number for the O--ring
is 4000171--240.
NOTE: For directional antennas, ACSS Part No. 7514060--90X, the customer must
provide an adapter plate for mounting to the aircraft. The antenna base
plate, to which the adapter must mate, is detailed in Figure 2--12.
Directional antennas, ACSS Part No. 7514081-- 9XX, come with a
preinstalled adapter plate.
(2) Omnidirectional Antenna Installation
The bottom omnidirectional antenna is a standard ATC type antenna. It should be
qualified to TSO C119b and be DC grounded per MIL --A--90941, B-- 5087B. All
L--band antennas must be separated by at least 20--inches. Only one coax cable is
required for installation.
The omnidirectional antenna is not supplied by ACSS. To install, follow the
manufacturer’s installation instructions.
D. GPS Antenna and Coax Provisions
Reference Figure 2--4 for the mechanical installations of the ACSS GPS Antenna. The
GPS installation design will consist of an A429 interface to the GPS sensor if the signal is
available, otherwise the T
2
CAS internal GPS module will be required. The installation
then consists of the installation of a GPS antenna and the coax cable to the T
2
CAS unit,
LBP pin 13.
Where the internal module is required, the T
2
CAS GPS Installati on Data Package
includes the GPS antenna mounting structure s provisions and all of the coax details to
secure the coax to the airframe and connect the T
2
CAS GPS antenna with the T
2
CAS
computer’s LBP pin 13.
The minimum combined coax and connector insertion loss between the GPS antenna’s
output and the T
2
CAS computer’s GPS input port is equal to the maximum preamplifier
gain minus 29 dB. The maximum coax loss between the GPS antenna’s output and the
T2CAS computer’s GPS input port is equal to the minimum preamplifier gain minus 12.5
dB.