Installation manual
AMX240 Audio Panel Installation Manual
200-890-0240 Rev. 02
0100. Ensure that proper strain relief and chafing precautions are made during wiring and installation, using the ca-
ble clamp, 625-001-0002.
Two solder grounding lugs, 475-009-0001, are provided, which may be attached to the rear mounting plate with 2 ea
#4-40 x ¼” screws with captivated lock washers. These provide a convenient location to connect the shield ground
terminations.
Manufacturer
Crimping Tool
Positioner
Extraction tool
AMP
601966-1
601966-6
91067-1
Daniels
AFM8
K42
M24308-1
ITT-Cannon
995-0001-584
995-0001-739
91067-1
Table 2-1 Connector Pin crimping tools
2.4 Cable Harness Wiring
Referring to the appropriate Appendix, assemble a wiring harness as required for the installation. All wires must be
MIL-SPEC in accordance with current regulations. Two- and three-conductor shielded wire must be used where
indicated, and be MIL-C-27500 or equivalent specification. Proper stripping, shielding and soldering technique must
be used at all times. It is imperative that correct wire be used.
Refer to FAA Advisory Circular 43.13-2B for more information. Failure to use correct techniques may result in im-
proper operation, electrical noise or unit failure. Damage caused by improper installation will void the Avidyne war-
ranty.
2.4.1 Electrical Noise
Due to the variety and the high power of radio equipment often found in today's general aviation aircraft, there is a
potential for both radiated and conducted noise interference.
The AMX240 power supply is specifically designed to reduce conducted electrical noise on the aircraft power bus
by at least 50dB. Although this is a large amount of attenuation, it may not eliminate all noise, particularly if the
amplitude of noise is very high. There must be at least 13.8 VDC present at the connector, J2 pins 8 & 9, of the
AMX240 for the power supply to work in its designed regulation. Otherwise, it cannot adequately attenuate power
line noise. Shielding can reduce or prevent radiated noise (i.e., beacon, electric gyros, switching power supplies,
etc.) However, installation combinations can occur where interference is possible. The AMX240 was designed in a
RFI hardened chassis and has internal Electromagnetic Interference (EMI) filters on all inputs and outputs.
Ground loop noise occurs when there are two or more ground paths for the same signal (i.e., airframe and ground
return wire). Large cyclic loads such as strobes, inverters, etc., can inject noise signals onto the airframe that are
detected by the audio system. Follow the wiring diagram very carefully to help ensure a minimum of ground loop
potential. Use only Mil Spec shielded wires (MIL-C-275000, or better). Under no circumstances combine a micro-
phone and headphone wiring into the same shielded bundle. Always use a 2- or 3-conductor, shield wire as shown
on the installation-wiring diagram.
The shields can be daisy-chained together, and then connected to the ground lugs mounted on the back plate shown
in Appendix B.
Radiated signals can be a factor when low level microphone signals are "bundled" with current carrying power
wires. Keep these cables physically separated. It is very important that you use insulated washers to isolate the
ground return path from the airframe to all headphone and microphone jacks.
2.4.1.1 Music Inputs and Noise
AMX240 units utilize a differential input to help prevent noise from entering the music system. This feature is usu-
ally transparent to the installer; however, it is important that the appropriate music signal and ground connections
are made directly to the dedicated music signal and ground inputs on the AMX240. The power for IFE and audio
panel should be a common bus.
If a music jack instead of a music source is installed for Music 1 or 2, we recommend grounding the jack to airframe
ground.
NOTE