Wulfsberg Electronics Division NPX136D 用户手册
NPX136D Panel Mount Radio Manual
SMtbd Rev. 0.01
Page 2-2
April 26, 2004
ENG-FORM: 805-0104.DOT
PROPRIETARY AND CONFIDENTIAL TO NORTHERN AIRBORNE TECHNOLOGY LTD.
2.3.3
Notes on Grounding
The case of the NPX136D must be electrically grounded for maximum resistance to low
frequency interference. A pin on the connector (Chassis ground) is provided and must be
connected by a short wire to a clean ground, not jumpered to the power ground wire
connection.
Refer to the aircraft structural repair manual and maintenance manual for instructions and
information pertinent to this installation.
frequency interference. A pin on the connector (Chassis ground) is provided and must be
connected by a short wire to a clean ground, not jumpered to the power ground wire
connection.
Refer to the aircraft structural repair manual and maintenance manual for instructions and
information pertinent to this installation.
2.3.4
Cable and Wiring
All wire should be in accordance with MIL -W-22759 unless otherwise specified. All cable
should be in accordance with MIL -C-27500 unless otherwise specified. Use solder sleeves
(for shielded terminations) to make the most compact and easy to terminate interconnect.
Follow the wiring diagrams in Section 2.5 as required.
should be in accordance with MIL -C-27500 unless otherwise specified. Use solder sleeves
(for shielded terminations) to make the most compact and easy to terminate interconnect.
Follow the wiring diagrams in Section 2.5 as required.
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.
easily installed. Note that the hood is installed after the wiring is complete.
Installation cabling must allow the NPX136D to be easily withdrawn for disconnection and
field service adjustments. Ensure an adequate service loop in the routing of the cables. It
can be a serious issue if the unit is installed with the cables so short that the unit cannot be
removed without disassembly of the surrounding structures. At least 30 cm (1 foot) of free
cable is recommended.
field service adjustments. Ensure an adequate service loop in the routing of the cables. It
can be a serious issue if the unit is installed with the cables so short that the unit cannot be
removed without disassembly of the surrounding structures. At least 30 cm (1 foot) of free
cable is recommended.
All wiring should be 22 AWG minimum, except power and ground connections, which must
be 20 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).
be 20 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).
Coaxial cable should be in accordance with MIL -C-17 unless otherwise specified. Do not
use coax with PVC insulation. Teflon dielectric cable is encouraged at or above VHF
frequencies or where cable runs exceed 8 feet. Note that at VHF frequencies, cable
losses due to long cable runs and tight bends may cut the ERP (Equivalent Radiated
Power) to less than 50% of spec.
use coax with PVC insulation. Teflon dielectric cable is encouraged at or above VHF
frequencies or where cable runs exceed 8 feet. Note that at VHF frequencies, cable
losses due to long cable runs and tight bends may cut the ERP (Equivalent Radiated
Power) to less than 50% of spec.
To prevent RF interference between similar systems, it is recommended that VHF FM coax
runs be widely separated, or be made using triaxial cable, with the outer shield bonded to
the airframe at one end only (transceiver end).
runs be widely separated, or be made using triaxial cable, with the outer shield bonded to
the airframe at one end only (transceiver end).
In communication intensive applications, poor cable routing and shielding may drastically
compromise over-all system performance. Symptoms may be spurious squelch opening,
RFI (Radio-Frequency Interference), and garbled reception.
compromise over-all system performance. Symptoms may be spurious squelch opening,
RFI (Radio-Frequency Interference), and garbled reception.