Northern Airborne Technology PA110 - Manual (Page 8)

PA110/220 High Power Audio Amplifiers
SM35 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.
PA220
Check the following:
a) P101 pins <6>, <24> and <25> for +28 Vdc relative to ground.
b) P101 pins <4>, <5> and <23> for continuity to ground (below 0.5
Ω).
c) Speaker connections are correct for the speaker impedance, and are not shorted.
2.4.5.2 Power On checks
a) Install the power amplifier and power up the aircraft's systems. Turn on all of the radios and other
accessories required for this system. Check that the PWR ‘on’ LED on the PA110/220 illuminates
when the power switch is up.
b) Select the rest of the audio system as required to allow connection of the pilot's mic to the ‘PA’
and key the cyclic switch for transmit. Check for correct radio operation and note what volume
settings will produce a suitable external paging level. Refer to the AA21 or AA22 Operator's
Manual for more detailed instructions.
Note: A faint audio signal heard at the speaker (even when the system is not paging) is common due to
the very high gain of this system and stray coupling in the wiring. It is not audible in flight.
Upon satisfactory completion of all performance checks, make all required log book entries, electrical
load, weight and balance amendments and other documentation as required by your local regulatory
agency before releasing the aircraft for service.
2.5 Accessories Required But Not Supplied
These units require installation kits to complete the installation.
2.5.1 PA110 Installation Kit (PA110-IKS)
Quantity Description NAT Part #
1 Connector, D-min 25 Socket Solder Cup 20-20-025
1* Jack Screw Set 20-27-002
1* Lock Clip set 20-27-004
1 25 Pin Connector Hood 20-29-026
* Use as required.
2.5.2 PA220 Installation Kit (PA220-IKS)
Quantity Description NAT Part #
1 Connector, D-min 37 Socket Solder Cup 20-20-037
1* Jack Screw Set 20-27-002
1* Lock Clip Set 20-27-004
1 37 Pin Connector Hood 20-29-038
* Use as required.