Northern Airborne Technology N301A - Manual (Page 10)

N301A-000 Audio Controller
SM45 Installation and Operation Manual
Section 2 Rev: 1.00 Issue 4 Page 2-3
ENG-FORM: 805-0117.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
2.4.4 Installation Notes
Follow instructions on installation drawings in section 2.7. If the receivers have very high output
impedance (great than 1000 ohms), they should be terminated with the internal load resistors. Four
600
Ω and two 150 Ω resistors are provided in each N301A-000 controller; only use one load resistor per
radio in the system.
The intercom tie lines and PVT tie lines should be also properly terminated with a load resistor.
Connect only one interphone load per aircraft system when used in installations that are configured with
Andrea interphone tie line connections. Connect the interphone loads on all units when used in
installations that are configured with the NAT ICS tie line connections.
The PVT ICS function only provides true ‘private’ communications when used in installations that are
configured with the Andrea interphone tie line connections. Installations configured with the NAT ICS tie
line will not provide ‘private’ intercom functions. Connect only PVT intercom load per aircraft system when
used in installations that are configured with the Andrea interphone tie line connections.
Only one ICS tie line configuration, either Andrea or NAT, can be connected per aircraft system.
Note:
All AA95/AMS4X Audio Controllers with S/N: 1918 or before used with the N301A-000 must have
the ICS Tie and Gain Modifications installed, or impaired intercom audio between units will result.
2.4.5 Mechanical Mounting
The N301A-000 can be mounted vertically or horizontally in standard Dzus rails.
Before the unit is mounted, make all functional tests, and trimpot adjustments. Be sure the harness has
enough clearance to permit the unit to be pulled out for re-adjustment, if needed later. Make sure the unit is
securely fastened to the Dzus rail, and that the connector locks are tightened before any flight is attempted.
2.4.6 Post Installation Checks
2.4.6.1 Voltage/Resistance Checks
Do not attach the N301A until the following conditions are met.
Check the following:
a) J101 pin <12> for +28 Vdc relative to ground.
b) J101 pin <11> for 0.5
Ω to ground.
2.4.6.2 Power On Checks
Power up the aircraft’s systems and confirm normal operation of all functions of the N301A. Refer to
Section 3 (Operation) for specific operational details.
a) Install the N301A-000 and power up the ship’s systems. Turn on the radios and accessories
required for the system.
b) Check for correct radio audio and adjust for acceptable level.