Northern Airborne Technology NPX136D - Manual (Page 13)

NPX136D Series Panel Mount P25 VHF Transceiver
SM68 Installation and Operation Manual
Section 2 Rev: 1.00 Issue 4 Page 2-4
ENG-FORM: 805-0118.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
Avoid antenna locations that will become fouled with oil, water, fuel or dirt, as this will degrade
performance. Roof mounts (in close proximity to rotor blades) are permissible.
2.4.6 Mechanical Mounting
Installation of the transceiver should be in accordance with the aircraft manufacturer’s instructions for
continued airworthiness or AC 43.13-1B Change 1, chapter 7, sections 2 to 7 and AC 43.13-2A, chapter 2.
Pr 35 Dzus rail or equivalent may be used.
Mounting the radio requires a Dzus rail assembly with an opening width of 5 inches (127 mm) and a front
clearance width of 5.75 inches (146.1 mm). Height requirement is 2.65" max (67.2 mm max). Refer to the
mounting drawings and unit mechanical specifications to determine proper clearance dimensions. Be
sure that adequate clearance is allowed for the cable connections to each unit.
2.4.7 Post-Installation Checks
2.4.7.1 Voltage/resistance checks
Do not attach the radio until the following conditions are met.
Check the following:
a) P1 pins <12> and <13> for +28 Vdc relative to ground.
b) P1 pins <22>, <23>, <24> and <25> for continuity to ground (below 0.5
Ω).
c) Light voltage as per table below.
Light Voltage P1 Pin # Voltage
28 Volt Models 11 28 Vdc
14 Volt Models 10 14 Vdc
5 Volt Models 10 5 Vdc
Ensure that the antenna is disconnected for the following test or erroneous readings may be obtained.
d) Radio coax connector for continuity to the antenna coax connector (shield and centre conductor),
and for open circuit from the centre conductor to ground and open circuit from the centre
conductor to the shield.
2.4.7.2 Power On Checks
a) Install the radio and power up the ship’s systems. Turn on the radio. Check the operation of all front
panel controls. Adjust brightness and volume levels as required.
b) Check all transmit and receive functions. Ensure the RX/TX status indicator lights green when the
radio is keyed to transmit and amber when receiving.
c) Check the SCAN function.
Note: You may be unable to hear the received audio if the tones do not match those set in the
radio. To avoid any confusion, tones should be set to OFF (via the settings menu) before
scanning so that all channels will be heard.