Northern Airborne Technology AA35 - Manual (Page 9)

AA35-001 Audio Mixer Panel
SM25 Installation and Operation Manual
Section 2 Rev: 1.00 Issue 4 Page 2-3
2.4.4.2 Power On Checks
Power up the aircraft’s systems and confirm normal operation of all functions of the AA35-001. Refer to
Section 3 (Operation) for specific operational details.
a) Check for the correct audio output on each channel.
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 Adjustments and Connections
WARNING:
These procedures should be performed by a qualified service
technician, at an ESD safe workstation only. Failure to adhere to this
warning could cause injury to personnel and/or damage to equipment.
2.5.1 8/600
Ω Adjustment
Remove the cover from the AA35 and locate the seven 8/600
Ω adjustment jumpers (JP1 thru JP7).
Each jumper controls one of the six independent channels or the Composite Output (refer to table 1).
When the jumper is connected across pins A and B, the channel is set to operate with an 8
Ω load
connected. When connected across B and C (the default setting), the channel is set to operate with a
600
Ω load connected. Refer to the Maintenance Section of this Manual for complete details.
Table 1: 8/600
Ω Jumpers
Jumper Channel
JP1 Channel 1
JP2 Channel 2
JP3 Channel 3
JP4 Channel 4
JP5 Channel 5
JP6 Channel 6
JP7 Composite Output
2.5.2 Input Audio Level Adjustment
The input audio level adjustment consists of six DIP switches (S1 thru S6), accessible from the right hand
side of the AA35. Each switch controls one of the six independent channels. The switch number reflects
the channel being controlled (e.g. S1 controls channel 1 and S4 controls channel 4). Each level can be
set to allow a 2.5 V (switch up) or a 7.5 V (switch down) input.
2.5.3 Composite Output Level Adjustment
The output level of the composite audio can be adjusted from the right hand side of the AA35. Rotating
the trim potentiometer from fully counter clockwise to clockwise will increase the output over a 40 dB
range.
ENG-FORM: 805-0117.DOT
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