Power Switch /Emergency
(EMG) Operation
Unit power is turned on and off by
pushing the volume knob. In the off or
"Emergency" position, the pilot is con-
nected directly to Com 1. This allows
communication capability regardless of
unit condition. Any time power is
removed or turned off, the audio selec-
tor will be placed in the emergency
mode.
The power switch also controls the
audio selector panel functions, inter-
com, and marker beacon receiver.
Unless the mic selector is in Com 3
mode, at least one of the selected
audio LEDs will be on (Com 1 or Com
2).
Microphone Selector
When the mic selector switch is in
the Com 1 position, both pilot and copi-
lot will be connected to the Com l trans-
ceiver. Only the person who presses
their Push To Talk (PTT), will be heard
over the aircraft radio. Turning the
rotary switch to the Com 2 position will
place pilot and copilot on Com 2.
The KMA 28 gives priority to the
pilot's PTT. If the copilot it transmitting,
and the pilot presses his PTT, the
pilot's microphone will be heard over
the selected com transmitter.
Turning the mic selector fully coun-
terclockwise places the pilot and copilot
on Com 3. Com 3 receive audio is
automatically placed in the headset
(and speaker if selected). Com 1 and/or
Com 2 receiver audio can be selected
to monitor those transceivers.
The KMA 28 has an automatic
selector mode. Audio from the selected
transceiver is automatically heard in the
headsets and speaker. You can check
this function by switching from Com 1
to Com 2 and watch the selected audio
light on the selector change from COM
1 to COM 2. This ensures the pilot will
always hear the audio from the trans-
ceiver he is transmitting on.
When transmitting, the COM 1 or
COM 2 LED in the KMA 28 audio
selector will blink as a further indication
of the selected transmitter.
When switching the mic selector
rotary switch from Com 1 to Com 2,
while Com 2 audio had been selected,
Com 1 audio will continue to be heard.
This eliminates the pilot having to
switch Com 1 audio back on, if desired.
When switching from Com 1 to Com 2
while Com 2 has NOT been selected,
Com 1 audio will be switched off. In
essence, switching the mic selector will
not effect the selection of Com audio.
Swap Mode (Switch from Com 1 to
Com 2 remotely)
With an optional yoke mounted,
momentary switch, the pilot can change
from the current Com transceiver to the
other by depressing this switch. When
"Swap Mode" is active, an annunciator
in the lower right corner of the unit will
illuminate, indicating that the mic selec-
tor switch position is no longer current .
To cancel "Swap Mode," the pilot may
either press the yoke mounted switch
again, or turn the mic selector switch to
the Com that is active.
Split Mode
Turning the rotary switch to Com
1/Com 2 places the KMA 28 into "Split
Mode." This places the pilot on Com 1
and the copilot on Com 2. An example
of this useful feature is when the pilot
may want to talk to Air Traffic Control,
while the copilot may be speaking to
Flight Watch. Although this mode has
limitations (see below) we believe you
will find this to be a useful feature.
Switching to Com 2/Com l will
reverse the "Split Mode" radio selec-
tion. The pilot will be on Com 2 and the
copilot will be on Com 1.
Note: Due to the nature of VHF commu-
nications signals, and the size constraints
6
Silver Crown Plus Pilot’s Guide
