TX56/56A and TX57/57A Installation Manual
5 April 2022
01776-00-01
Issue AD
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Page 44
Trig Avionics
CDI Style
Examples
Menu Choice
No external device – using Nav/Com front
panel
N/A
INTERNAL
The choice of CDI also affects the behaviour of the Nav/Com.
Selecting CONVERTER means that the internal CDI display is
disabled, and Nav dual watch is also not available.
Selecting RESOLVER or SERIAL means that the OBS for both the
external device and the internal CDI is controlled by the external OBS
knob.
6.2.8
OBS Calibration
If a resolver type of interface has been selected, you will be offered the choice
of calibrating the device. Although they are set at the factory there are usually
small variations in the OBS interface which can be corrected by the Nav/Com.
Once selected, the calibration process involves selecting in turn twelve equally
spaced bearings on the external instrument: 000°, 030°, 060°, 090°, 120° and
so on up to 330°.
6.2.9
Remote Protocol Choice
The Nav/Com can emulate either the Apollo SL30 Nav/Com or the Garmin
GNC255 Nav/Com. This allows compatibility with a wide range of third party
systems. If available on the device you are connecting, for maximum feature
support, including control of 8.33 kHz frequencies, choose the Garmin
protocol.
6.2.10
Auxiliary Input Volume
The auxiliary input is a low-fidelity monophonic input intended for Nav radio
ident inputs and simple annunciators. This setting controls the relative volume
of the auxiliary audio input.
6.2.11
Auxiliary Input Muting
This allows the auxiliary input to be muted when the radio is receiving or
transmitting speech. Turn this feature ON if the auxiliary input is being used
