Northern Airborne Technology STX100 - Manual (Page 18)

STX100-000 Globalstar ™ Satphone Transceiver Manual SM67 Rev. 4.10
2.3
Installation Procedures
2.3.1 Warnings
Do not bundle any lines from this unit with transmitter coax lines. Do not bundle any
logic, audio, or DC power lines from this unit with 400 Hz synchro wiring or AC power
lines. Do not position this unit next to any device with a strong alternating magnetic field
such as an inverter or significant interference to operation will result. In all installations,
use shielded cable exactly as shown and ground as indicated. Significant problems
may result if these guidelines are not followed.
2.3.2 Cautions
All audio installations can be severely degraded by incorrect wiring and shielding, and
may result in much higher cross-talk, hum, and ground-loop interference. This should
be considered when audio wiring to and from the radio system installation is performed.
In communication intensive applications, poor cable routing and shielding may drastically
compromise over-all system performance. Use caution in the routing of wire bundles.
The STX100-000 can be connected to and used with a 2-wire handset, however the
handset current must not exceed 30 mA due to restrictions in the loop current available
from the 2-wire POTS interface in the STX100-000. The handset should be powered
from the aircraft’s electrical buss to ensure proper operation of the satphone system.
2.3.3 Notes
The case of the STX100-000 must be electrically grounded for maximum resistance to
low frequency interference. Pin 16
(CHASSIS GROUND) on connector P103 is provided
and must be connected by a short wire to a clean ground, not jumpered to the power
ground wire connection.
2.3.4 Cable and Wiring
All unshielded wire shall be selected in accordance with AC43.13-1B Change 1,
Paragraphs 11-76 through 11-78. Wire types should be to MIL-W-22759 as specified in
AC43.13-1B Change 1, Paragraphs 11-85, 11-86, and listed in Table 11-11. For
shielded wire applications, use Tefzel MIL-C-27500 shielded wire with solder sleeves
(for shield terminations) to make the most compact and easily terminated interconnect.
Follow the wiring diagrams in Section 2.7 as required.
All wiring should be 22 AWG minimum, except power and ground connections, which
must be 18 AWG or larger, as indicated on the installation drawings. Ensure that the
ground connection is clean and well secured. To prevent inadvertent system failure,
power to this system must be supplied from a separate breaker or fuse and not
connected to any other device. A 5 A fuse or breaker is recommended (28 Vdc).
Allow 3 inches from the end of the wire to the shield termination to allow the hood to be
easily installed. Note that the hood is installed after the wiring is complete.
Page 2-2 Sep 7, 2005
ENG-FORM: 805-0106.DOT
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