600-00174-001
Rev. 03, 13 May 2008
29
WSI AV-300/350 Installation Manual
R
ECEIVER
A
NTENNA
C
ONNECTIONS
Do not over-tighten the connector or internal damage to the receiver or the antenna could result.
The connector on the receiver and antenna is hard mounted. If a connector turns in its mounting,
it needs to be repaired.
P
OWER
I
NPUT
L
INE AND
G
ROUND
R
ETURN
Ensure that the receiver is well grounded to an effective airframe ground. Poor grounds or
ground loops can cause intermittent operation or alternator noise in the headphones. If there is
any question about the effectiveness of the ground, route the return line to the battery terminal.
A
UDIO
The AV-350 audio output is designed to operate into a 600-ohm load. If an audio port must be
shared with another audio input, series resistors should be used in both lines to allow sufficiently
high audio volume for both audio inputs. Usually 220 to 470 ohm resistors are satisfactory.
Connection to an audio panel without internal amplification may require a supplemental
amplifier. Low audio is usually caused by a greater than normal load on the line due to multiple
inputs to one audio port.
A dedicated audio ground return line is provided to eliminate possible audio whine. Connect the
audio return to the ground for the audio port to which the AV-350 receiver is connected. If no
return ground is provided, ground to the case of the audio panel.
The audio line from the AV-350 receiver to the audio panel should be shielded, with the shield
grounded at the audio panel.
NOTE:
All AV-350 audio installations that have audio available to the flight crew must
have an audio mute switch installed, and have the AV-350 audio suppression
connected to all higher priority equipment. The audio mute switch should be
installed in a position easily accessible to the pilot. This will allow the flight crew
to quickly MUTE the AV-350 audio when needed. The AV-350 audio
suppression line must be connected to higher priority systems to prevent the AV-
350 audio from interfering with communication, navigation, and safety systems.
All other systems audio alerts are higher priority than AV-350 audio.
I
NSTALLATION IN A
S
EVERE
EMI
E
NVIRONMENT
Proper grounding of the AV-300/350 receiver is essential. If the EMI environment is anticipated
to be severe, route the cable bundles through an overall shield (in addition to the shields
specified in the wiring diagrams). The outer shield should be terminated to aircraft ground at the
receiver end of the cable bundle.
