6
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Installing the Flightcell VAM
Flightcell VAM Installation and Configuration Manual
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If more than one microphones need to have access to the VAM, an external switch is required to select
the active microphone input to MIC TO VAM HI.
3.3.2.2
Connecting to a cell phone port on the audio panel:
Some audio panels have a dedicated cell phone port, which provides a convenient connection option. The MIC
TO VAM HI
line is connected to the audio panel’s cell phone
output. Please consult your audio panel
installation manual for more details.
Depending on the way this connection is configured in the audio panel, this option may require the user
switch the mic away from the radio when on a call.
See the VAM wiring diagrams for an example of this configuration.
3.3.2.3
Connecting to a spare transceiver position on the audio panel:
On aircraft with separate audio control panels at each crew position, this option enables crew to use the VAM
and connected phone individually on demand.
On aircraft using high impedance (electret, dynamic or carbon) microphones, a bias voltage is commonly
required on MIC HI
lines to the audio panel, in order to energize the user’s microphone when using the
VAM.
If mic bias is required, the biased MIC TO VAM connections must be used (refer to pin out listing in section 4
for details on biased/unbiased mic connections).
3.4
Connecting to the aircraft power supply
The VAM unit and Iridium cradle require aircraft DC power. Operating range is 12-32VDC.
It is recommended that the VAM be connected to the emergency (primary) power bus on the aircraft.
When operating on a nominal 28V supply, circuit breakers or fuses of the following rating should be used
between VAM system components and the power supply:
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A 1-amp circuit breaker/fuse is recommended to protect a Flightcell VAM and Iridium phone cradle.
3.4.1
Iridium Cradle Power Supply
The VAM unit provides a power pass through on pins 2 and 10; so that the Iridium cradle (or other attached
equipment) may be powered from the same supply without the need to splice cables (refer to pin out listing in
section 4 for details).
