J301A-001 Audio Controller
Installation and Operating Manual
Rev A
Page 18
(11)
VOX Threshold Control
This is a rotary knob marked VOX that is used to select the VOX
threshold of the unit. See
below.
When rotated fully clockwise (CW), the threshold will be at maximum
and VOX ICS operation is disabled and ICS PTT input is required for
ICS operation.
When rotated fully counterclockwise (CCW), the threshold will be at minimum (almost live).
To adjust the unit for
VOX
(Voice activated) use, the VOX control should be set fully CCW and then slowly rotated CW
to the point where no intercom audio can be heard. The VOX control should be adjusted for proper operation
according to the ambient noise.
3.3
Normal Operation Mode
Note
: Numbers in parentheses refer to the front panel controls shown in section 3.2.
The J301A-001 is in Normal mode when the front panel TX select switch
(4)
is in position COM1 through COM8 or
ICS and suitable electrical power is supplied to the unit.
3.3.1
Panel Lighting
The legends and annunciators will be illuminated (when appropriate) and dim through the aircraft lighting buss.
3.3.2
Receiving
When the J301A-001 receives an incoming transmission on a transceiver or receiver that has been selected, either by
the white transceiver receive switches
(1)
or the transmit selector
(4)
, the incoming audio will be directed to the user’s
phones.
The audio level of any incoming transmission will depend upon the level selected by the front panel RX volume control
(8)
. It will be muted if the unit is transmitting and muting of receive audio during transmit is enabled.
3.3.3
Transmitting (Transmit Operation)
To select a transceiver, rotate the Transmit Select Switch until it aligns with the line leading to the Transceiver Select
switch legend (see
(1)
) - default legends COM1 to COM8, or ICS/
RMT
The corresponding Transmit Select
annunciator will illuminate.
When the user’s TX PTT is activated, the unit will transmit on the selected transceiver, and the deadfront Transmit
Annunciator
(6)
will illuminate ‘TX’. Sidetone audio will be routed to the user’s phones, and music will be muted for the
duration of the transmission.
3.3.4
VOX Operation
The VOX Threshold level is at minimum when the front panel control is fully CCW, and at maximum when fully CW.
The
user’s MIC audio is routed to the ICS when the MIC audio level exceeds the VOX threshold.
The
user’s MIC audio is disconnected from the ICS when the MIC audio level falls below the VOX threshold for 0.5 to
2 seconds.
