Northern Airborne Technology 240 - Manual (Page 10)

Model 240 Passenger Speaker Amplifier
SM240 Installation and Operation Manual
Section 2 Rev: 1.01 Issue 4 Page 2-4
ENG-FORM: 805-0121.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
Pin Identification, P50 (37 pin connector):
1. Audio Common (except stereo) 20 Audio Common (except stereo)
2. PA MIC Hi 21. Audio Common (except stereo)
3. Paging Volume 22. Audio Common (except stereo)
4. Briefer Audio Hi 23. No Connection
5. Stereo Switch 24. PA Key
6. Left Input Hi 25. Briefer Switch
7. Left Input Lo 26. No Connection
8. Right Input Lo 27. Audio Common (except stereo)
9. Right Input Hi 28. Audio Common (except stereo)
10. No Connection 29. No Connection
11. Receiver Volume Control 30. No Connection
12. No Connection 31. Smoking Sign Switch
13. TV Switch 32. Seat Belt Sign Switch
14. PSC Switch 33. Cabin Call Switch
15. ADF 2 Switch 34. Hook Switch
16. ADF 1 Switch 35. PA Sidetone Hi
17. ADF 1 Audio Hi 36. Audio Common (except stereo)
18. TV Audio Hi 37. ADF 2 Audio Hi
19. PSC Audio Hi
2.4.7 Post-Installation Checks
2.4.7.1 Voltage/Resistance Checks
Do not attach the Model 240 until the following conditions are met.
Use the pin identification information in Section 2.4.5 above and the Installation Procedures Wiring
Diagrams in the drawings section to check all the pins for the correct line voltages or continuity to ground.
2.4.7.2 Post Installation Information
The Right and Left Speaker Amplifier is designed for speech and music signals and has both a Rated and
a Continuous Power specification. The Continuous rating is the power the amplifier can continuously
deliver with a sine wave. The Rated Power specification is the peak power it can deliver without clipping.
Bench testing and adjustments may require brief periods of sine wave operation above the Continuous
rating; those periods should be limited to 1 minute to prevent amplifier damage. Power ratings are as
follows:
Load
Rated Power Continuous Power
2 Ohm 20 W 2 W
4 Ohm 10 W 1 W
2.4.7.3 Power On Checks
Power up the aircraft’s systems and confirm normal operation of all functions of the Model 240.
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.