Installation Manual

THALES Communications
OIM
AHV1600-SYSTEM
Page 202
July 16/09

VSWR 3 to 1 of each antenna (return loss of - 6 dB or less) over the frequency range 4.2 GHz to
4.4 GHz.

All sides lobes of each antenna must be down 40 dB or better.

Coax cable 50 ohms double shielded type RG400 or equivalent.
 Losses in both the transmission and reception coaxial cables are of 4 dB minimum and 7 dB
maximum.

Each antenna shall be grounded on the aircraft frame, on a common metallic grounded structure
for both antennae. The dimension of this structure being at least 15 cm around each antenna.

No conductive features between antennae or within at least 30 cm around each antenna should
be accepted. Furthermore no conductive features should be seen in a cone of ± 70° centered on
each antenna.
 Avoid antennae to be fitted close to landing gear doors, landing gear or skids.
 Antennae should be preferably installed on a flat and horizontal surface. In any cases two an-
tennae of a given system shall have no more than a 5° angle between their planes. Furthermore,
users have to take into account the fact that tilting any antenna with respect to the aircraft hori-
zontal plane will affect the system performances in terms of capability to withstand aircraft’s atti-
tudes.

The residual resistance between the structure of the aircraft and the structure of each antenna
(body of the coaxial connector) shall not exceed 2.5 milliohm.

The residual resistance between the structure of the aircraft and the structure of the transceiver
(body of the coaxial connector, main connector or specific reference mechanical ground pins in
the main connector) shall not exceed 2.5 milliohm.
2. STEP BY STEP TRANSCEIVER INSTALLATION
The AHV1600 Transceiver is fitted with a main MIL-C-38999 series III, 37 contacts connector and two female
MIL-C-39012/TNC coaxial connectors.
Two antennae ANT140A – transmission and reception – are required for the AHV1600 Transceiver. They are
connected by means of two coaxial cables to the AHV1600 Transceiver.
Recommended installation flowcharts:

control the Transceiver visual aspect,

secure the Transceiver,
 connect the Main connector,
 connect the coaxial cables.
Warning: before connecting Main connector, be sure 28 Vdc Transceiver supply is inhibited.