AA95-766 Single Channel Audio Controller
SM95-766 Installation and Operation Manual
June 20, 2012 Rev: 3.00
Page 2-4
ENG-FORM: 805-0100.DOTX
CONFIDENTIAL AND PROPRIETARY TO ANODYNE ELECTRONICS MANUFACTURING CORP.
Plug in the hand mic (if installed) and test for correct operation. (Hand mic activation does
not
illuminate
the TX light.) Note that wiring faults for this accessory may cause peculiar loss of ICS or TX functions
because it has over-riding priority in the system.
Plug in the remaining headsets (hi-z mic, hi-z phones) and check for proper operation. Note that an
incorrect cordset (drop cord) or improper jack wiring may cause a wide range of problems from loss of
audio to a tone heard in the headset. For further information, see section 2.3.7 below.
Note
: Different headsets may have significantly different mic characteristics, which will affect VOX
squelch settings.
Check levels and operation of all functions in flight to ensure proper adjustments and settings have been
made.
Upon satisfactory completion of all performance checks, make the required log entries and
complete the necessary Regulatory Agency paperwork before releasing the aircraft for service.
2.3.7
In-line PTT Cordsets
2.3.7.1 General
In-line, push-to-talk (PTT) cordsets (also known as drop cords) can be used to create/provide PTT
capability for the user headsets that do not have yoke or cyclic mounted PTT switches. For headsets
connected to the PILOT or COPILOT inputs/outputs, ICS and TX keylines are needed to properly activate
the associated PTT circuitry inside the AA95-766. For headsets connected to the PASSENGER
inputs/outputs of the AA95-766, a method of controlling the microphone on the headset is needed
because of the 'hot mic' circuitry. This is best accomplished with a 'mic interrupt' switch in the PTT
cordset.
There are numerous manufacturers of in-line PTT cordsets, offering many 'electrical' variations to
accomplish different functions. To meet the operational requirements for headset stations supported by
the AA95-766, AEM recommend the dual switch type: a 3-position (momentary/center-off/locking) slider
switch for the ICS functions, and a momentary, push-button switch for the Transmit functions. Both
switches provide a ‘mic interrupt’ function. The 3
-position ICS switch will allow the user to change the
switch settings to match the operational intercom mode that has been selected (e.g., LIVE, KEYED or
VOX). The cable should have 6 conductors, with the MIC and PHONE pairs shielded (MIC wires must be
shielded as a minimum). To ensure proper shielding, the shield(s) should be terminated to the MIC LO
connection at the airframe connector of the PTT cordset. See the drawing below for details.
