Honeywell KMA 28 User manual

KMA 28
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KMA 28
Audio Amplifier/Intercom/Marker Beacon Receiver
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KMA 28 Operation
KMA 28 Control Function
Receive Audio Selectors
Receiver audio is selected
through two momentary and six
latched, pushbutton, backlit switches.
Com 1 and Com 2 are the momentary
switches.
Because the rotary microphone
selector switch controls what
transceiver is being heard, the Com l
and Com 2 push-buttons are of the
momentary type and do not remain in
when selected. This is also part of the
"auto" function. You will always hear
the audio from the transceiver that is
selected for transmit by the rotary mic
selector switch.
The users can identify which
receivers are selected by noting which
of the green switch LEDs are
illuminated. Push buttons labeled Nav
1, Nav 2, DME, MKR (Marker), ADF,
AUX (auxiliary), and SPR (Speaker)
are "latched" type switches. When
one of these buttons is pressed, it will
stay in the "in" position. Press the
switch again and it be in the "out"
position and remove that receiver
from the audio.
Key "click"
The KMA 28 is equipped with an
electronic "click" to provide additional
feedback for button operation. To
activate the key click, push and hold
BOTH COM 1 and COM 2 receiver
buttons for five seconds, and release.
Repeat to defeat the click.
Speaker Amplifier
The "SPR" in the push-button
section stands for speaker. This
switch will place all selected audio on
the cockpit speaker when this switch
is selected.
Public Address (PA) Function
The KMA 28 has a public
address capability when an optional
external PA switch is installed. When
this switch is put into the PA position,
the pilot's microphone is placed on a
speaker output. The copilot can
continue to use the selected Com
radio.
When this PA function is installed
a separate cabin speaker (rather than
the cockpit speaker) is usually utilized
to prevent feedback.

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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
connected directly to Com 1. This
allows communication capability
regardless of unit condition. Any time
power is removed or turned off, the
audio selector will be placed in the
emergency mode.
The power switch also controls
the audio selector panel functions,
intercom, 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
copilot will be connected to the Com l
transceiver. 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
counterclockwise 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 transceiver 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 selector 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

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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
selection. The pilot will be on Com 2
and the copilot will be on Com 1.
NOTE: Due to the nature of VHF
communications signals, and the size
constraints in general aviation aircraft,
it is probable that there will be some
bleed-over in the Split mode,
particularly on adjacent frequencies.
In addition, if the Com radios in the
installation utilize a "transmit interlock"
system, the split mode may not work
properly unless the interlock feature is
disabled.
NOTE: Honeywell makes no
expressed or implied guarantee
regarding the suitability of Split Mode
in a given installation.
NOTE: Split Mode does not turn off
other (Nav, ADF, etc.) selected audio
to pilot. However, the copilot will only
hear the selected communications
receiver and unswitched audio.
Split Mode ICS
In split mode, the pilot and copilot
are isolated from each other on the
intercom, simultaneously using their
respective radios. Depressing the ICS
button in Split Mode will activate VOX
intercom between the pilot and copilot
positions. This permits
intercommunication when desired
between the crew. Pressing the ICS
button again disables this crew
intercom function.
Telephone Mode
The "TEL" position, fully CW on
the mic selector switch, is the pilot's
"hook" switch. This is active only
when the system is interfaced to an
appropriate approved system, such as
the AirCell™ system. Placing the mic
selector in TEL places the pilot
microphone and headphones on the
cellphone. The pilot PTT will switch
the pilot mic to the COM 1, and allow
continued aircraft communications as
well.
NOTE: Placing the mic selector
switch in the TEL position will disable
pilot and copilot intercom, as the
intercom circuit is transferred to the
telephone use. In crew or ISO mode,
placing the switch in TEL mode
removes the passengers access to
the telephone.
If interface is desired with another
type of wireless telecommunications
unit, the aircraft owner can purchase
an after-market interface cable. By
Federal Communications Commission
(FCC) regulations, these can only be
used on the ground in the United
States.
Interface cables are available for
specific telephones. The following is a
partial list of available interface
cables:
Compatible Phones
Audiovox Series 5
Motorola TeleTAC, DPC 550,
DPC65-, Lite Series, Profile Series
Motorola Elite, M70, M75, SC-725
Motorola Bag Phones, Mobiles
NEC100 Series, 110, 120, 180, Sport
NEC 700 & 800 Series
OKI 900/910, AT&T 3730/3710
OKI 1150/1145, AT&T 3760
Fujitsu PCX
Mitsubishi 4000, DiamondTel

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22X/20X/18X
NEC960
NEC DT2000 Digital Phone
NOTE: Unauthorized use of cellular
telephone devices in aircraft is subject
to FCC enforcement action, which
may include a $10,000 fine per
incident. Honeywell , Inc. does not
endorse using unapproved cellular
telephone equipment in flight, and
takes no responsibility for the user’s
action.
Intercom System
‡ IntelliVox™ VOX-Squelch@@
No adjustment of the IntelliVox™
squelch control is necessary. Through
three individual signal processors, the
ambient noise appearing in all six
microphones is constantly being
sampled. Non voice signals are
blocked. When someone speaks, only
their microphone circuit opens,
allowing him or her to communicate
on the intercom.
NOTE: InteliVox™ is a registered
trademark of PS Engineering, Inc. and
is used by permission
The system is designed to block
continuous tones; therefore people
humming or whistling in monotone
may be blocked after a few moments.
For best performance, the headset
microphone must be placed within º
inch of your lips, preferably against
them. It is also a good idea to keep
the microphone out of a direct wind
path. Moving your head through a
vent air stream may cause the
IntelliVox™ to open momentarily. This
is normal.
For optimum microphone
performance, Honeywell recommends
installation of a Microphone Muff Kit
from Oregon Aero (1-800-888-6910).
This will not only optimize VOX
acoustic performance, but will
improve the overall clarity of all your
communications.
Volume Control
The volume control knob adjusts
the loudness of the intercom for the
pilot and copilot only. It has no effect
on selected radio levels, music input
levels or passengers' volume level.
Adjust the radios and intercom
volume for a comfortable listening
level for the pilot. Most general
aviation headsets today have built-in
volume controls; therefore, passenger
volume can be adjusted at the
headset.
Mono headsets in Stereo
Installation
All passenger headsets are
connected in parallel. Therefore, if a
monaural headset is plugged in to a
Stereo KMA 28 installation, one
channel will be shorted. Although no
damage to the unit will occur, all
passengers will lose one channel.
Intercom Modes
The lower switch on the left side
is a 3-position mode switch that
allows the pilot to tailor the intercom
function to best meet the current
cockpit situation.
ISO (Up Position): The pilot is
isolated from the intercom and is
connected only to the aircraft radio
system. He will hear the aircraft radio
reception (and sidetone during radio
transmissions). Copilot will hear
passengers' intercom and
Entertainment 1, while passengers
will hear copilot intercom and
Entertainment 2. Neither will hear

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aircraft radio receptions or pilot
transmissions.
ALL (Middle Position): All parties will
hear the aircraft radio and intercom.
Crew will hear Entertainment 1,
passengers will hear Entertainment 2.
During any radio or intercom
communications, the music volume
automatically decreases. The music
volume increases gradually back to
the original level after
communications have been
completed.
CREW Down Position): Pilot and
copilot are connected on one intercom
channel and have exclusive access to
the aircraft radios. They may also
listen to Entertainment 1. Passengers
can continue to communicate with
themselves without interrupting the
Crew and also may listen to
Entertainment 2.
Anytime the KMA 28 is in either
the Com 1/Com 2, Com 2/Com 1,
("Split Mode"), the pilot and copilot
intercom is controlled with the ICS
button. The passengers will maintain
intercommunications, but never hear
aircraft radios.
Mode Pilot Hears Copilot Hears Passenger Hears Telephone Comments
Isolate
A
/C Radios
Pilot Sidetone
(during radio
transmission)
Entertainment #1
is Muted
Popilot and
passenger
intercom
Entertainment #1
Passenger and
Copilot intercom
Entertainment #2
“Phone Booth”
mode
Pilot has
exclusive use of
the telephone.
In TEL, Pilot
connected to
Com 1 for PTT
TX and receive.
This mode
allows the pilot
to communicate
without the
others bothered
by the
conversations.
Copilot and
passengers can
continue to
communicate
and listen to
music
All Pilot
Copilot
A/C Radio
Passengers
Entertainment #1
Copilot
Pilot
A/C Radio
Passengers
Entertainment #1
Passengers
Pilot
Copilot
A/C Radio
Entertainment #2
A
ll have access
to phone through
Hook Switch.
Pilot access
through TEL
switch.
All hear
telephone audio.
This mode
allows all on
board to hear
radio reception
as well as
communicate on
the intercom.
Music and
intercom is
muted during
intercom and
radio
communications
Crew Pilot
Copilot
A/C Radio
Entertainment #1
Copilot
Pilot
A/C Radio
Entertainment #1
Passengers
Entertainment #2
Pilot and Copilot
don’t have
phone access,
unless mic sel in
TEL.
Passengers
have phone
through Hook
Switch,
Passengers hear
phone audio.
This mode
allows the Pilot
and Copilot to
concentrate on
flying, while the
passengers can
communicate
amongst
themselves.
Table 2. Intercom Modes

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Entertainment Input
The audio selector panel has
provisions for two separate
entertainment input devices. They
operate independently in the KMA 28.
The volume control does not affect
music level.
While in the ISO (Isolate) mode,
the copilot will hear Entertainment 1
while the four passengers will hear
Entertainment #2. The pilot will hear
Entertainment 1 at a level muted
about 95%. In normal operation,
whenever a person speaks, or if the
aircraft radio becomes active, the
music will automatically mute and
then will gradually return to the
original listening level when the
intercom or radio conversation
ceases.
When in the All mode, pilot and
copilot will hear Entertainment 1 input
while all passengers will hear the
Entertainment 2 source. While in the
Crew mode, pilot and copilot will hear
entertainment input #1 while the
passengers may listen to
entertainment input #2.
Soft Mute and Soft Mute inhibit
The Soft Mute feature assures
that the aircraft radio transmissions
will not be missed due to
entertainment playing. When there is
radio reception or intercom
conversation, the music level is
dropped to a background level. When
the radio or intercom traffic ceases,
the level gradually returns to normal.
The front panel ICS switch
controls muting of entertainment
source #1. Pushing this button places
the ICS in Karoake (or sing along)
mode, which inhibits the soft mute
feature. This allows the music to
continue uninterrupted by intercom or
radio traffic when cockpit workload is
appropriate. Pushing the button again
will release the mute inhibit function.
The passenger music, source #2,
can be placed in the Karaoke mode if
a remote switch is installed in the
aircraft.
Marker Beacon Operation
The Marker Beacon Receiver
uses visual and audio indicators to
alert you when the aircraft passes
over a 75 MHz transmitter. The audio
from the Marker Beacon Receiver can
be heard by selecting the "MKR"
push-button switch.
A three-position switch is used to
set the receiver sensitivity and to test
the indicator lamps. Use "High"
sensitivity initially. This allows you to
hear the outer marker beacon about a
mile out. Then select the "Low"
sensitivity to give you a more accurate
location of the Marker. When used
only for approach markers, many
pilots choose to leave the switch in
the low sensitivity position.
The momentary down switch
position is labeled "T/M" (Test/Mute)
and illuminates all three lamps
simultaneously to assure they are in
working order.
The "T/M" position is also a
Marker Beacon "Mute" function.
Pushing this switch while receiving a
marker beacon signal will cause the
audio to be temporarily silenced. No
action is required to restore the audio
in time for the next beacon.
Telephone Operation (if
equipped with approved
system)
Each intercom position has a
"hook switch." The pilot's hook switch
is the "TEL" mode on the mic selector,
the others are individual switches

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mounted adjacent to the headset
jacks.
When the intercom is in ALL
mode, the pilot can speak on the
phone only if the mic selector switch
is in TEL position. All intercom
positions will hear the telephone
conversation. Anyone who places his
or her switch into the "offhook"
position will also be heard on the
phone. All will hear selected audio.
Com 1 audio is automatically heard in
the headsets. The pilot will have
transmit capability on Com 1, simply
by using the PTT switch.
In CREW mode, the pilot and
copilot may use the telephone, with
their respective hook switch (the pilot
selects TEL on the mic selector). Any
passenger who places their switch
into the offhook position will also have
access to the phone, and all four
passengers will hear the
conversation.
In ISO intercom mode, when the
KMA 28 is in the TEL mode, the pilot
position is in the "Phone Booth." Only
the pilot will hear the telephone, and
only he will be heard. He will also
have access to Com 1, and will
transmit on that radio using the PTT.
All selected audio is provided.
In all cases, only the pilot (and
copilot in ALL or CREW) will hear the
cellphone ring. At that time they can
chose to allow a passenger to take
the call, or answer the phone.
NOTE: Because the phone uses an
intercom circuit, all stations on that
circuit will lose intercom capability
when it is in use.
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