8
•
Configuration
Flightcell VAM Installation and Configuration Manual
5
Configuration
The headset output from the VAM is capable of driving a
headset with an impedance of between 8 and 600Ω.
The output is balanced line and galvanically isolated.
The audio input and output on th
e sat phone side are both of 600Ω
nominal impedance and are balanced line
and galvanically isolated.
The VAM has an internal power-present LED indicator mounted in the end panel next to the pre-set
adjustments.
5.1
Level adjustment
Three level adjustments are provided
–
these are accessible by removing the dust cover plug (labelled SIM) in
the front of the enclosure and can be adjusted using a small blade or cross point screwdriver. The pre-sets are
labelled
on the circuit board as ‘MIC’
(RV1)
, ‘S
PK
’
(RV3)
and ‘ST’
(RV2).
The Mic pre-set adjusts the level of the mic audio being sent from the VAM to the sat phone cradle. Spk adjusts
the level of the sat phone speaker audio being transmitted from the VAM to the ICS. ST adjusts the level of the
sidetone audio provided by the VAM on the ICS MIC/Audio connection.
If sidetone is not required, the
‘ST’
pre-set should be set to minimum. The other level adjustments should be
set as appropriate for the equipment that is connected; the design is such that setting both to approximately
halfway will give levels that are suitable for an aviation headset and a Flightcell sat phone cradle.
