117-00008 Rev 3.0 Flightcell® DZMx Installation Manual
Page 23 of 75
Effective Date: 18 February 2022
Dual Calling
The DZMx can make two calls simultaneously:
»
If the two ICS connections are wired, separate calls on ICS1 and ICS2.
»
If only ICS1 is wired to the audio system, two calls on the single ICS channel.
Call Priority
A modem which has been given priority will automatically mute all other calls when it makes or
receives a call. When a priority call has ended, it automatically unmutes any other call. This can
be particularly useful if a call on a modem is vital to vehicle aircraft operations. By default, call
priority is off, however it can be enabled using the "Call Priority" setting for each modem in DZMx
Connect. Go to
Settings > Audio > Modems
. This option can be found in the settings under the
audio section. This setting is particularly useful for simultaneous calls on a single ICS channel.
Audio from the DZMx to the ICS
Audio from the DZMx is connected direct to the ICS input, and its levels adjusted using the DZMx
audio menu.
Audio from the ICS to the DZMx (microphone installation)
The DZMx can be installed in aircraft systems with either high impedance or low impedance
microphones. Most (but not all) civil aircraft operate high impedance (electret) microphone
systems. Most (but not all) military aircraft operate low impedance microphone systems. Refer to
for wiring diagrams for the microphone connections.
Low Impedance Microphones
When installing the DZMx with an ICS that uses low impedance mics, the DZMx must be
connected to a line level Radio/Comms port. If a line-level port is not available and the DZMx is to
be connected direct to the mic line, then a tactical radio adaptor will be needed to match
impedances. Options include the NAT AA34-300, Jupiter JA34-001 or PS Engineering 200-002-
0002.
High Impedance Microphones
There are several options for connecting the DZMx into an audio panel/ICS with high impedance
microphones. The way in which the DZMx is connected will depend on your system configuration
and operational requirements.
As the Iridium satellite phone and cell phone are both full duplex, it is preferable to use the DZMx
on a hot mic connection, rather than PTT (keyed). The DZMx will typically be installed in one of
the following ways:
»
Connecting Directly to a Headset Microphone Line.
»
The MIC lines are spliced to one or more headset microphone inputs on the audio panel.
As these microphone inputs have mic bias provided by the audio panel, the DZMx should
have mic bias disabled.
»
The way this is configured will depend on how many headsets are to have access to the
DZMx.
»
If only the pilot is to use the DZMx, its MIC TO DZMx 1 HI/LO lines are connected only
to the pilot’s microphone line.
»
If both pilot and co-pilot are to use the DZMx, the MIC lines are connected to the pilot
microphone line and the MIC lines are connected to the co-pilot microphone line.
