Honeywell Kma28 Users Manual Installation
KMA28 to the manual 8d32ed7e-a75b-4947-8dee-790ca5c72d72
2015-01-23
: Honeywell Honeywell-Kma28-Users-Manual-261879 honeywell-kma28-users-manual-261879 honeywell pdf
Open the PDF directly: View PDF .
Page Count: 35
- Section I GENERAL INFORMATION
- Section II - Installation
- SCOPE
- Certification Requirements
- Cooling Requirements
- Mounting Requirements
- Mounting Rack Installation
- Connector Assembly
- Noise
- Existing KMA-24 Installation
- Existing PS Engineering PMA6000 installations
- Power
- Communications Push-to-Talk
- Transmit Interlock
- "Swap" Mode
- Backlighting
- Unswitched inputs
- Intercom wiring
- Com 3 Audio
- Public Address function
- PA Mute (J1, Pin 18)
- Control Output (J2, Pin A)
- VOX Override (J2, Pin U)
- Middle Marker Sense
- External Marker Lights
- Marker Antenna Installation
- Communications Antenna Installation Notes
- Wireless telecommunications interface
- KMA 28 Pin Assignments
- Post Installation Checkout
- Unit Installation
- Cellular Interface Checkout
- Final Inspection
- Section III KMA28 OPERATION
- Appendix A – Installation Drawings
- Appendix B Bottom Connector Interconnect
- Appendix C Top Connector Interconnect
- Appendix D- Instructions for FAA Form 337 and Continuing Airworthiness
- Instructions for Continuing Airworthiness,
- Appendix E RTCA DO160C (EUROCAE ED-14) Environmental Qualification Form
![](asset-1.png)
Installation and Operation Manual
BENDIX/KING
BENDIX/KINGBENDIX/KING
BENDIX/KING
®
KMA 28
FAA-Approved TSO C50c, C35d
JAA-Approved JTSO-2C35d, C50c
Audio Amplifier /Intercom/
Marker Beacon Receiver
Document P/N 006-10565-0000
REVISION 0, SEPTEMBER 2000
WARNING
Prior to export of this document, review for export license requirement is needed.
Honeywell International, Inc. 2000©
Copyright Notice
Reproduction of this publication, or any portion thereof, by any means without the express written permission of Honeywell
International, Inc. is prohibited. For further information contact the Manager, Technical Publications; Honeywell Business &
General Aviation, Olathe, Kansas 66061. Phone (913) 782-0400.
![](asset-2.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page iRev. 0, Sept. 2000
Table of Contents
1 SECTION I GENERAL INFORMATION ......................................................................... 1-1
1.1 INTRODUCTION...........................................................................................................1-1
1.2 SCOPE.............................................................................................................................1-1
1.3 EQUIPMENT DESCRIPTION.....................................................................................1-1
1.4 APPROVAL BASIS - .....................................................................................................1-2
1.5 SPECIFICATIONS ........................................................................................................1-3
1.6 EQUIPMENT SUPPLIED.............................................................................................1-4
1.7 EQUIPMENT REQUIRED BUT NOT SUPPLIED....................................................1-5
1.8 LICENSE REQUIREMENTS.......................................................................................1-5
2 SECTION II - INSTALLATION ......................................................................................... 2-1
2.1 GENERAL INFORMATION........................................................................................2-1
2.1.1 SCOPE........................................................................................................................2-1
2.1.2 CERTIFICATION REQUIREMENTS.................................................................................2-1
2.2 UNPACKING AND PRELIMINARY INSPECTION................................................................2-1
2.3 EQUIPMENT INSTALLATION PROCEDURES....................................................................2-1
2.3.1 COOLING REQUIREMENTS...........................................................................................2-1
2.3.2 MOUNTING REQUIREMENTS .......................................................................................2-1
2.3.3 MOUNTING RACK INSTALLATION ...............................................................................2-2
2.3.4 CONNECTOR ASSEMBLY .............................................................................................2-2
2.4 CABLE HARNESS WIRING ...............................................................................................2-2
2.4.1 NOISE ..........................................................................................................................2-2
2.4.2 EXISTING KMA-24 INSTALLATION.............................................................................2-3
2.4.3 EXISTING PS ENGINEERING PMA6000 INSTALLATIONS ............................................2-3
2.4.4 POWER ........................................................................................................................2-3
2.4.5 COMMUNICATIONS PUSH-TO-TALK ............................................................................2-3
2.4.6 TRANSMIT INTERLOCK................................................................................................2-3
2.4.7 "SWAP" MODE ............................................................................................................2-4
2.4.8 BACKLIGHTING ...........................................................................................................2-4
2.4.9 UNSWITCHED INPUTS..................................................................................................2-4
2.4.10 INTERCOM WIRING ....................................................................................................2-4
2.4.11 COM 3 AUDIO............................................................................................................2-5
2.4.12 PUBLIC ADDRESS FUNCTION.....................................................................................2-5
2.4.13 PA MUTE (J1, PIN 18)...............................................................................................2-6
2.4.14 CONTROL OUTPUT (J2, PIN 4)...................................................................................2-6
2.4.15 VOX OVERRIDE (J2, PIN U) .....................................................................................2-6
2.5 MARKER INSTALLATION.................................................................................................2-6
2.5.1 MIDDLE MARKER SENSE ............................................................................................2-6
2.5.2 EXTERNAL MARKER LIGHTS ......................................................................................2-6
2.5.3 MARKER ANTENNA INSTALLATION ............................................................................2-6
2.6 ADJUSTMENTS..................................................................................................................2-7
2.7 COMMUNICATIONS ANTENNA INSTALLATION NOTES ..................................................2-7
2.8 WIRELESS TELECOMMUNICATIONS INTERFACE ...........................................................2-7
2.8.1 HOOK SWITCHES.........................................................................................................2-8
2.9 KMA 28 PIN ASSIGNMENTS ...........................................................................................2-9
2.10 POST INSTALLATION CHECKOUT ...............................................................................2-10
2.11 UNIT INSTALLATION....................................................................................................2-10
![](asset-3.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page ii Rev. 0, Sept. 2000
2.11.1 OPERATIONAL CHECKOUT ......................................................................................2-10
2.11.2 RECEIVER SENSITIVITY...........................................................................................2-11
2.12 CELLULAR INTERFACE CHECKOUT ...........................................................................2-11
2.13 FINAL INSPECTION.......................................................................................................2-11
3 SECTION III KMA28 OPERATION ................................................................................. 3-1
3.1 AUDIO SELECTOR ............................................................................................................3-1
3.1.2 SPEAKER AMPLIFIER...................................................................................................3-1
3.1.3 PUBLIC ADDRESS (PA) FUNCTION .............................................................................3-2
3.2 POWER SWITCH /EMERGENCY (EMG) OPERATION.....................................................3-2
3.3 MICROPHONE SELECTOR................................................................................................3-2
3.3.1 SWAP MODE (SWITCH FROM COM 1 TO COM 2 REMOTELY) ...................................... 3-3
3.3.2 SPLIT MODE ................................................................................................................3-3
3.3.3 TELEPHONE MODE......................................................................................................3-3
3.4 INTERCOM SYSTEM .........................................................................................................3-4
3.4.1 INTELLIVOX® VOX-SQUELCH....................................................................................3-4
3.4.2 VOLUME CONTROL .....................................................................................................3-5
3.5 MARKER BEACON OPERATION ......................................................................................3-7
3.6 TELEPHONE OPERATION (IF EQUIPPED WITH APPROVED SYSTEM).............................3-7
4 APPENDIX A – INSTALLATION DRAWINGS ................................................................ A
5 APPENDIX B BOTTOM CONNECTOR INTERCONNECT ........................................... B
6 APPENDIX C TOP CONNECTOR INTERCONNECT ..................................................... C
7 APPENDIX D- INSTRUCTIONS FOR FAA FORM 337 AND CONTINUING
AIRWORTHINESS ...................................................................................................................... D
7.1 INSTRUCTIONS FOR FAA FORM 337 ................................................................................ D
INSTRUCTIONS FOR CONTINUING AIRWORTHINESS, AUDIO PANELS ................. D
APPENDIX E RTCA DO160C (EUROCAE ED-14) ENVIRONMENTAL
QUALIFICATION FORM .......................................................................................................... E
![](asset-4.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 1-1 Rev. 0, Sept. 2000
Section I GENERAL INFORMATION
1.1 INTRODUCTION
The KMA 28 represents the next step in cockpit audio control and intercommunications.
Using proprietary IntelliVox® design, this unit eliminates the requirements for intercom
squelch adjustments. The unit is designed for outstanding ergonomics and visually de-
fined mode annunciation and selection.
Before installing and/or using this product, please read this manual completely. This will
ensure that you will take full advantage of all the advanced features in the KMA 28.
1.2 SCOPE
This manual provides detailed installation and operation instructions for the Honeywell,
Inc. KMA 28 Audio Selector Panel/Intercom System
Model Description Part Number
KMA 28 Stereo Audio Panel with Marker 066-01176-0101
1.3 EQUIPMENT DESCRIPTION
The KMA 28 is a state of the art audio isolation amplifier and audio selector that contains
an automatic voice activated (VOX) intercom system. It can switch up to three transceiv-
ers (Com 1, Com 2 and Com 3) and six receivers (Nav 1, Nav 2, ADF, DME, MKR and
AUX).
The TEL mode allows the KMA 28 to act as an audio interface between aircraft head-
phone and microphones and specific aircraft approved (FAA/FCC) cellular telephone
equipment.
Warning
: Use of non-aviation approved cellular telephone equipment may be prohibited by regulation.
Honeywell, Inc. is not responsible for unauthorized airborne use of cellular telephones.
There are two unswitched inputs, for autopilot disconnect, and/or radar altimeter warning.
Push buttons select the receiver audio source provided to the headphones. A SPR button
allows the user to listen to the receiver(s) selected on the cabin speaker. Except for the
unswitched inputs, all speaker audio is muted during transmit.
A rotary switch selects one of the three communication transceivers for the pilot and co-
pilot position, and allows radio transmission. In "Split Mode" the KMA 28 has the ability
to allow the pilot and copilot to operate different transceivers independently. The TEL
mode allows the pilot to use the cellular telephone interface. External switches permit
telephone operation for the copilot and passengers.
An emergency mode connects the pilot headphone and microphone to COM 1 if power is
removed for any reason, or if the power switch is placed in the Off (emergency ) position.
I
ntelliVox® is a trademark of PS Engineering, Incorporated, and used with their permission
![](asset-5.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 1-2 Rev. 0, Sept. 2000
A six-station voice activated (VOX) intercom is included in the KMA 28. This system
has the advanced IntelliVox® circuitry that eliminates manual adjustments. The system
contains six separate VOX mic circuits, and only opens the microphone channel in use.
The intercom system incorporates pilot isolate and crew modes, two stereo (or mono de-
pending on unit) music inputs with "Soft Mute," and LED indicators for swap and trans-
mit indications. Intercom control is through front panel-mounted knob and 3 position
mode switch. A single volume controls intercom level for the pilot and copilot. Passenger
headphone volume is factory set, and adjusted in flight with headset-mounted volume
controls. Passenger volume control is further adjustable through screwdriver access in the
top of the unit. Intercom squelch is automatic.
A 3-light Marker Beacon receiver is integrated in the KMA 28. This provides the neces-
sary Marker Beacon lights and audio indications necessary for an Instrument Landing
System (ILS) approach.
1.4 APPROVAL BASIS -
TSO Approval.
The KMA 28 Audio Selector Panel is FAA approved under TSO C50c (Audio Amplifi-
ers) and TSO C35d (Marker Beacon Receivers). In addition, they are approved by the
Joint Airworthiness Authorities under JTSO C50C and JAR-TSO 2C35d. The TSO
holder and manufacturer is PS Engineering, Incorporated, Lenoir City Tenn., USA.
The KMA28 complies with relevant portions of EUROCAE RTCA MPS WG No. 7/70,
DO-143 and (Marker Beacon Receivers), ED-14C/DO-160C (Environmental Conditions
and Test Procedures for Airborne Equipment), ED12B/DO-178B (Software Considera-
tions for Airborne Equipment) and ED- 18/DO-214 (Audio Systems Characteristics and
Minimum Operational Performance Standards for Aircraft Audio Systems).
Operation is subject to the following conditions:
This device may not cause harmful interference.
This device must accept any interference received, including interference that may cause
undesired operation.
![](asset-6.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 1-3 Rev. 0, Sept. 2000
1.5 SPECIFICATIONS
TSO COMPLIANCE
Marker Beacon: C35d, Class A
Audio Selector/Intercom: C50c, Class A
APPLICABLE DOCUMENTS: RTCA/DO-214
RTCA/DO-143
RTCA/DO-160C
RTCA/DO-178B
ENVIRONMENTAL Qualifications: A1D1/CA(MN)XXXXXXBBBBTBKXX
Temperature Range:
Operating:
Storage:
-15º C to +55ºC
-55º C to +85ºC
Altitude: Up to 50,000 feet in an non-pressurized area of
the cockpit.
DIMENSIONS: Height: 1.3 in. (3.3 cm) Width: 6.25 in. (16.9 cm)
Depth: 6.8 in. (17.3 cm)
WEIGHT (With Rack & Connectors): 1.5 lb. (0.54 kg)
POWER REQUIREMENTS (Including Internal Lighting):
Voltage: 11 to 33 VDC
Maximum Current: 2.5 Amp (Externally protected by a 3 Amp circuit
breaker.)
Typical operating current:
Speaker off:
Speaker on, 28V, full radio volume
350 mA
1.5 A
Audio Selector Specifications
Audio selector panel input impedance:510 Ω
Input Isolation: -60 dB (min.)
Speaker Muting: -60 dB (min.)
Speaker Output (into 4 Ω) with no clipping
14 VDC:
28 VDC:
3 Watts (min.)
10 Watts (min.)
Receiver Inputs:9
(Com 1, Com 2, Com 3, Nav 1, Nav 2, ADF,
DME, MKR, AUX)
Unswitched Inputs:2
(examples: GPS WPT, Value, Autopilot Discon-
nect, Altimeter DH)
Transmitter Selections:6
(Com 1, Com 2, Com 3
Com1/2, Com2/1, Telephone)
Speaker Impedance:4 Ω
Headphone Impedance:150 - 1000 Ω
Headphone Output: 38 mW each headset, no clipping <1% THD
70 mW each headset with < 10% THD into 150Ω
Microphone Impedance:150 - 600 Ω
![](asset-7.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 1-4 Rev. 0, Sept. 2000
Intercom Specifications
Intercom Positions: 6 places (with individual IntelliVOX® circuits)
Music Inputs: 2 (Stereo)
Music Muting: >-30 dB "Soft Mute" when Com or intercom active.
Distortion: <1% THD @ 38 mW into 150Ω
<10% THD @ 70mW into 150 Ω
Mic Freq. Response, 3 dB: 300 Hz - 6000 Hz
Music Freq. Response, 3 dB: 100 Hz - 18kHz
MARKER BEACON RECEIVER
Frequency: 75 MHz Crystal Controlled
Sensitivity:
Low:
High:
Capable of:
1000 µVolts (Hard)
200 µVolts (Hard)
(preset at factory for field application)
Selectivity: -6 dB at ±10 kHz
-40 dB at ±120 kHz
External Lamp Output: 9.0 (±2.5 unloaded, at maximum brightness) VDC posi-
tive when active, max. current 125 mA
MM Sense: Active high (4.7 VDC ± 0.5V) during Middle Marker
acquisition, for autopilot use.
1.6 EQUIPMENT SUPPLIED
1 ea. of the following:
Model Part Number
KMA 28 066-01176-0101
KMA 28 Installation Kit, 050-03613-0001, contains the following parts.
Description Quantity Part
Number
KMA28 install rack 1 071-00164-0001
Top Molex Connector Shell w/key, 44 pin, key 4/5 1 120-425-4402
Bottom Molex Connector Shell w/key, 44 pin, key 7/8 1 120-425-4400
Gold Plated Crimp Pins 88 425-001-0002
4 40 X 7/16 screw w/nyl patch 4 475-440-0007
Grounding strap 1 430-007-0001
6-32 X 3/4 screw php 2 475-632-0038
6-32 Nut Flat 2 475-632-0003
6-32 Lock Nut 2 475-632-0004
Cable Clamp 1 625-001-0002
#6-32 x ½” FHP screw 6 475-632-0012
#6-32 Clip Nut 6 475-630-0002
The KMA 28 install rack may be purchased separately under part number 071-00164-0001.
![](asset-8.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 1-5 Rev. 0, Sept. 2000
1.7 EQUIPMENT REQUIRED BUT NOT SUPPLIED
a) Circuit Breaker: 1 ea. 3 amp
b) Speaker, 4 Ω
c) Headphone Jacks (Stereo, as Required)
d) Microphone Jacks (as Required)
e) Headphones, 150 Ω (Stereo), up to 6 as required
f) Microphones, up to 6 as required
g) Marker Antenna (75 MHz, VSWR <1:1.5, 50 ohm, and cable (RG400 R/U)
h) Interconnect Wiring
1.8 LICENSE REQUIREMENTS
None
![](asset-9.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 2-1 Rev. 0, Sept. 2000
Section II - Installation
2.1 GENERAL INFORMATION
2.1.1 SCOPE
This section provides detailed installation and interconnect instructions for the Honey-
well, Inc. KMA28 Audio Selector Panel/Intercom System with internal Marker Beacon.
Please read this manual carefully before beginning any installation to prevent damage and
post-installation problems. Installation of this equipment requires special tools and
knowledge.
2.1.2 Certification Requirements
When the digital audio warning system is installed in a certified aircraft, certification ba-
sis is the installer’s responsibility. Due to the variety and options available for interface,
Honeywell will only provide manufacturers’ data for our equipment interface.
2.2 Unpacking and Preliminary Inspection
Use care when unpacking the equipment. Inspect the units and parts supplied for visible
signs of shipping damage. Examine the unit for loose or broken buttons, bent knobs, etc.
Verify the correct quantity of components supplied with the list in Section 1.6. If any
claim is to be made, save the shipping material and contact the freight carrier. Do NOT
return units damaged in shipping to Honeywell. If the unit or accessories shows any sign
of external shipping damage, contact Honeywell to arrange for a replacement. Under no
circumstances attempt to install a damaged unit in an aircraft. Equipment returned to
Honeywell for any other reason should be shipped in the original packaging, or other UPS
approved packaging.
2.3 Equipment Installation Procedures
2.3.1 Cooling Requirements
Forced air cooling of the KMA 28 is not required. However the unit should be kept away
from heat producing sources (i.e. defrost or heater ducts, dropping resistors, heat produc-
ing avionics) without adequate cooling air provided.
2.3.2 Mounting Requirements
The KMA 28 must be rigidly mounted to the instrument panel of the aircraft structure and
within view and reach of the pilot position(s). Installation must comply with FAA Advi-
sory Circular AC 43.13-2A. The unit may be mounted in any area where adequate clear-
ance for the unit and associated wiring bundle exist.
Avoid installing the audio panel close to high current devices or systems with high-
voltage pulse type outputs, such as DME or transponders.
![](asset-a.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 2-2 Rev. 0, Sept. 2000
2.3.3 Mounting Rack Installation
Set the unit aside in a safe location until needed. Install the tray using six FHP 6-32 x ½"
screws. The audio selector panel must be supported at front and rear of the mounting tray.
2.3.4 Connector Assembly
The unit connectors mate directly with the circuit boards in the KMA 28. The connectors
are a Molex crimp-type, and require the use of a Molex hand crimp tool, EDP P/N 11-01-
0203, CR6115B (or equiv.). The connectors are mounted to the unit tray with #4-40
screws, from the inside of the tray. Ensure that proper strain relief and chafing precau-
tions are made during wiring and installation.
2.4 Cable Harness Wiring
Referring to the appropriate Appendix, assemble a wiring harness as required for the in-
stallation. All wires must be MIL-SPEC in accordance with current regulations. Two- and
three-conductor shielded wire must be used where indicated, and be MIL-C-27500 or
equivalent specification. Proper stripping, shielding and soldering technique must be used
at all times. It is imperative that correct wire be used.
Refer to FAA Advisory Circular 43.13-2A for more information. Failure to use correct
techniques may result in improper operation, electrical noise or unit failure. Damage
caused by improper installation will void the warranty.
2.4.1 Noise
Due to the variety and the high power of radio equipment often found in today's general
aviation aircraft, there is a potential for both radiated and conducted noise interference.
The KMA 28 power supply is specifically designed to reduce conducted electrical noise
on the aircraft power bus by at least 50dB. Although this is a large amount of attenuation,
it may not eliminate all noise, particularly if the amplitude of noise is very high. There
must be at least 13.8 VDC present at the bottom connector, pin 20, of the KMA 28 for the
power supply to work in its designed regulation. Otherwise, it cannot adequately attenuate
power line noise. Shielding can reduce or prevent radiated noise (i.e., beacon, electric gy-
ros, switching power supplies, etc.) However, installation combinations can occur where
interference is possible. The KMA 28 was designed in a RFI hardened chassis and has
internal Electromagnetic Interference (EMI) filters on all inputs and outputs.
Ground loop noise occurs when there are two or more ground paths for the same signal
(i.e., airframe and ground return wire). Large cyclic loads such as strobes, inverters, etc.,
can inject noise signals onto the airframe that are detected by the audio system. Follow
the wiring diagram very carefully to help ensure a minimum of ground loop potential. Use
only Mil Spec shielded wires (MIL-C-275000, or better).
Radiated signals can be a factor when low level microphone signals are "bundled" with
current carrying power wires. Keep these cables physically separated. It is very important
![](asset-b.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 2-3 Rev. 0, Sept. 2000
that you use insulated washers to isolate the ground return path from the airframe to all
headphone and microphone jacks.
2.4.2 Existing KMA-24 Installation
If the installation replaces a KMA-24 (series –00, -01, -02 or -03), the existing 44 pin
connector can be used for the bottom connector of the KMA 28 tray as is, providing it is
properly installed and wired. No other changes are required except for external marker
lights (see Appendix B for details). The "key" in the existing connector must be located
between pins 7 and 8. This connector will be used in the bottom connector position. (See
Appendix for complete wiring harness details.)
The existing ground bus may be reused for radio shield connections, if it was constructed
so it can be relocated to the KMA 28 tray.
2.4.3 Existing PS Engineering PMA6000 installations
In 28-Volt aircraft, the dropping resistor may be removed, however, the 2 Amp breaker
should be changed to 3 Amp. If either old unit is stereo (PMA6000S or PMA6000MS),
no rewiring is necessary unless additional features are added.
2.4.3.1 Stereo KMA 28 installations into existing monaural PS Engineering
PMA6000, PMA6000M.
Installations replacing PMA6000 or PMA6000M require re-wiring of the top connector to
accommodate the stereo configuration. See appendixes for detailed interconnect informa-
tion.
2.4.4 Power
The KMA 28 is compatible with both 14 and 28 Volt DC systems. A two (2) Amp circuit
breaker is required for 14 VDC installations, and a three (3) Amp breaker for 28 VDC
aircraft. Power and ground wires must be a twisted #18 AWG pair. Connect airframe
power ground to J1 (bottom connector) Pin Z only. No dropping resistors are required.
2.4.5 Communications Push-to-Talk
An important part of the installation is the PTT (Push-To-Talk) switches that allow the
use of your aircraft communications radio for transmissions. Only the person who presses
their PTT switch will be heard over the radio. If the pilot and copilot both use the PTT,
only the pilot position has access to the radio. The pilot position will have PTT control
regardless of the mic selector switch or copilot PTT when the KMA 28 is in the
EMERGENCY mode.
2.4.6 Transmit Interlock
Some communications transceivers use a transmit-interlock system. To fully utilize the
Split Mode feature, this function must be disabled. Consult that manufacturer's installa-
tion manual.
![](asset-c.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 2-4 Rev. 0, Sept. 2000
2.4.7 "Swap" Mode
When a momentary, normally open, push-button switch is connected between pin 10 on
the top connector and aircraft ground, the user can switch between Com 1 and 2 by de-
pressing this switch without having to turn the mic selector switch. This yoke-mounted
switch eliminates the need to remove your hands from the yoke to change transceivers.
2.4.8 Backlighting
The KMA 28 has an automatic dimming of the pushbutton annunciator LEDs and marker
lamps controlled by a photocell. Control of the unit backlighting is through the aircraft
avionics dimmer. Connect the dimmer control line to J1 pin D for 14 volt systems, and to
J1 pin F for 28 volt systems. Pin E is light ground.
If an external dimmer control is not used, a constant low level back light illumination can
be established for nighttime viewing. Pin D or F (depending on system voltage) must be
tied to power (J1, pin 20) for the back lighting system to work. The photocell mounted in
the unit face will automatically adjust the intensity of the push-button annunciator LEDs.
2.4.9 Unswitched inputs
J1, pin T is the unswitched input number 1 and J1 pin 17 is unswitched input 2. These
inputs are presented to the pilot and copilot regardless of the audio configuration, and will
always mute the entertainment inputs. These 510Ω inputs can be used for altimeter DH
audio, GPS waypoint audio, autopilot disconnect tones, air-to-ground (Flitefone) tele-
phone ringer or any other critical audio signal. This input is not related to the cellular
telephone interface.
2.4.10 Intercom wiring
The top connector (J2) is for the intercom and additional functions. See Appendix for in-
tercom connection configurations. It is critical to the proper operation of this system to
have this connector wiring made in accordance with these diagrams. Use 2- and 3-
conductor, MIL-spec cable as shown. Connect the shields at the audio panel end only, and
tie to the audio low inputs as shown.
2.4.10.1 Entertainment Input
NOTE: Use the low level output of any entertainment device to connect to
the audio panel. Maximum signal level is 1 VAC p-p.
DO NOT use a speaker-level output, this will cause internal damage in the
audio panel
2.4.10.1.1 Stereo entertainment
Two stereo entertainment devices (CD player, cassette player, etc.) can be connected to
the unit. Install two 1/8-inch stereo jacks in a convenient location so that the pilot can plug
![](asset-d.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 2-5 Rev. 0, Sept. 2000
in the entertainment devices into the system. The audio signal at the entertainment input
must be a minimum of 500 mV P-P per channel for optimum music performance.
All entertainment devices must be switched off for both takeoff and landing.
2.4.10.1.2 Entertainment distribution
Entertainment source #1 provides music for the pilot and copilot positions, while enter-
tainment source #2 provides music for the four passenger positions. The KMA 28-system
incorporates a "Soft Mute" system. This will mute the entertainment devices during ICS
or radio conversation.
Any signal appearing in the unswitched audio inputs will always mute the entertainment
sources, even though the passengers may not hear the audio tone itself.
Entertainment inputs #1 and #2 can be paralleled so a single entertainment source can
serve both the passengers and the crew. It is suggested however, that a switch (DPDT) is
installed between the single entertainment device and entertainment input #1. This will
allow the pilot and copilot to decide if they hear entertainment while in the Crew mode.
Caution: Local oscillators and internal signals from some entertainment equipment can
cause undesired interference with other aircraft systems. Before takeoff, operate the en-
tertainment devices to determine if there is any adverse effect within the aircraft systems.
If any unusual operation is noted in flight, immediately switch off the entertainment de-
vices.
All entertainment devices must be switched off for both takeoff and landing.
2.4.10.1.3 Entertainment 2 Mute (Pin V)
The ICS button on the KMA 28 controls the muting (“Karoake mode”) of entertainment
source #1.
Connecting J2 pin V to ground through a SPST switch places the entertainment #2 music
source into the Karoake Mode. In this mode, incoming music and intercom conversation
will not mute the music for the passengers’ intercom net. This allows uninterrupted music
during casual conversation and at times when radio communications are of lessor impor-
tance.
2.4.11 Com 3 Audio
As installed in the standard configuration, the KMA 28 Com 3 audio is heard while the
mic selector switch is in the Com 3 position (fully CCW). Pushing the receiver selector
buttons can monitor Com 1 and Com 2 audio. If monitoring of Com 3 is desired in Com 1
or Com 2 mic selector position, connect Com 3 audio in parallel to the AUX input (J1,
pin 11).
2.4.12 Public Address function
The KMA28 has a Public Address function. By connecting the top connector (J2), Pin 18
to ground, the pilot’s microphone audio is placed on the cabin speaker output. When the
![](asset-e.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 2-6 Rev. 0, Sept. 2000
pilot’s PTT is activated, his voice is heard over the speaker. The copilot can continue to
use the selected com.
We recommend installing a toggle switch to connect the cabin speaker output (pin W,
bottom connector) to a rear or public address speaker instead of the cockpit speaker close
to the pilot. This will prevent feedback.
2.4.13 PA Mute (J1, Pin 18)
Pin 18 of J1 is a TTL logic output that is pulled low during PTT operation. This serves as
an input to external public address system to prevent feedback during transmissions.
2.4.14 Control Output (J2, Pin A)
Pin A of the top connector is pulled to ground whenever the AUX button is depressed.
This serves as a control line for external devices, such as a entertainment system that the
pilot wishes to control.
2.4.15 VOX Override (J2, Pin U)
Connecting pin U of the KMA 28 of J2 to ground will force the IntelliVox® open. This
can be hooked up as a hot mic switch which will place all microphones on the intercom.
This can also be connected through a momentary switch to serve as a VOX test switch, if
desired. Because the IntelliVox® will close in the presence of a steady tone, this pin is
used in testing to defeat the IntelliVox® software.
2.5 Marker Installation
The marker beacon receiver is included in the KMA 28.
2.5.1 Middle Marker Sense
A Middle Marker sense output signal is available from the KMA28 to flight control sys-
tems. This function will not operate during the test mode. This output will go to +4.7
VDC (± 0.5 VDC) when a valid Middle Marker signal is received. This output is J1, pin
2.
2.5.2 External Marker Lights
For installations that require external marker beacon lights, there are three outputs that
can drive 12-Volt lamps only. The external output lamps are driven high (+9 VDC ±1.5
VDC) when active. Maximum source current per lamp is 125 mA. Voltage varies with
photocell dimming.
2.5.3 Marker Antenna Installation
Refer to aircraft and antenna manufacturer's installation instructions, as well as AC43.13-
2A (or later revision), Chapter 3, for information on proper antenna installation tech-
niques. The marker beacon antenna must be mounted on the bottom of the aircraft.
![](asset-f.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 2-7 Rev. 0, Sept. 2000
2.6 Adjustments
The KMA 28 is factory adjusted to accommodate the typical requirements for most air-
craft configurations. There are five adjustments however, that will allow the installer to
tailor the specific functions.
Marker Gain
CW- Reduce
Passenger Volume
CCW Increases
Marker Audio
CW Decrease Volume
MKR Low Sense
CW Decrease Sens.
Front of Unit
KMA28 adjustment holes
Not used
Speaker Volume
CW-Increase
211
231
223
133
111
Figure 2-1- KMA 28 Adjustments
2.7 Communications Antenna Installation Notes
For best results while in Split Mode, it is suggested that the one VHF communications
antenna is located on top of the aircraft while the other communications antenna is in-
stalled on the bottom. Any antenna relocation must be accomplished in accordance with
AC 43.13-2A, aircraft manufacturers’ recommendations and FAA-approved technical
data.
Warning:
It is probable that radio interference will occur in the split mode when the frequencies
of the two aircraft radios are adjacent, and/or the antennas are physically close to-
gether. Honeywell makes no expressed or implied warranties regarding the suitability
of the KMA 28 in Split Mode.
2.8 Wireless telecommunications interface
The KMA 28 has interface capability with units such as the AirCell units. It is the user’s
responsibility to determine the appropriate legal use of the equiment, and provide the
services.
Interface to the AirCell unit is through J1 (bottom) connector, pins 14 and N. Pin 14, la-
beled cellphone ring, is connected to pin V of the 3100D J3 connector and pin N of J1 is
![](asset-10.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 2-8 Rev. 0, Sept. 2000
connected to pin W of the J3 connector. On the AirCell interface diagram these are listed
as data/fax lines, but they are used for voice interface in this case.
Use a 2-conductor with shield cable, and connect the shield to Pin M of the J3.
If interface is desired with another type of wireless telecommunications unit, the aircraft
owner can purchase an after-market interface cable. By Federal Communications Com-
mission (FCC) regulations, these can only be used on the ground in the United States.
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.
2.8.1 Hook Switches
While the mic selector acts as the hook switch for the pilot, additional hook switches
must be installed to have full access to the cellphone system. The copilot hook switch is a
SPST switch that connects pin L of J2 on the KMA 28 to ground to place the copilot on
the cellphone.
KMA 28 J2, pin M is the passenger hook switch. Install a SPST switch in a location adja-
cent to each passenger headset where cellphone use is desired. When pin M is connected
to ground through any switch, the passenger microphones are all on the cellphone system.
The wireless communication “tel” system utilizes an intercom loop. Therefore, any time
the cellphone is in use from the pilot or copilot side, pilot and copilot will lose intercom
capability. In the ALL mode, when the passengers’ activate the cell phone, the pilots will
have intercom, and continue to hear and transmit over the avionics normally. However
the passengers will not have intercom, because they are on the telephone.
To prevent unwanted distractions, only the pilot and copilot will hear an incoming call
ring signal. They can then decide to allow a passenger to activate the hook switch and use
the telephone.
If the pilot has selected “TEL” mode, the passengers cannot access the telephone in the
“CREW” intercom mode, but they will hear the call.
![](asset-11.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 2-9 Rev. 0, Sept. 2000
2.9 KMA 28 Pin Assignments
Pilot Phone Audio Hi (Left)
Copilot Phone Audio (Lt)
Copilot Phone Audio Lo
Copilot Phone Audio (Rt)
Pass 1 Mic Audio Hi
Pass 1 Mic Audio Lo
Pass 2 Mic Audio Lo
Pass 2 Mic Audio Hi
Pass 3 Mic Audio Hi
Pass 3 Mic Audio Lo
Pass 4 Mic Audio Hi
Copilot Mic Audio Hi
Pass Cellphone Off Hook
Copilot Mic Key
Copilot Mic Audio Lo
Swap Switch
Pass 4 Mic Audio Lo
Copilot Cellphone Off Hook
Passenger Headphone Audio (R)
Passenger Headphone Audio (L)
Passenger Headphone Audio Lo
Entertainment #2 In (R)
Entertainment #1 In (R)
Ent 2 Mute
Entertainment # 2 Lo
Entertainment #1 In (L)
Entertainment #1 Lo
Ground
IntelliVOX Over ride
Reserved
1
A
2
B
3
C
4
D
5
E
6
F
7
H
8
J
9
K
10
L
11
M
12
N
13
P
14
R
15
S
16
T
17
U
18
V
19
W
20
X
21
Y
22
Z
Entertainment #2 In (L)
J2 Top Connector
Pilot Mic Audio Hi In
Com 3 Audio Hi
Com 1 Audio Hi
Com 2 SPKR Load
AUX Audio Input Hi
Com 1 Spkr Load
Com 2 Audio Hi
Aircraft Power 11-33 VDC
ADF Audio Hi
Com 2 SPKR load
Unswitched Audio In #1
Unswitched Audio In #2
Com 3 Mic Key
Com 1 Mic Key
Nav 2 Audio Hi
Com 1 Mic Audio Out
Cellphone ring
Cellphone tip
Nav 1 Audio Hi
Com 2 Mic Audio Out
28V Lights Hi
Light Lo
14 V Light Hi
Amber Lamp Out
PA Mute
Chassis Ground
Aircraft Ground
Cabin Spkr Lo
Pilot Mic Key
Cabin Spkr Out
Com 1 SPKR load
DME Audio Hi
Blue Lamp Out
White Lamp Output
Pilot Headphones
MM Sense Output
MKR Coax Lo
Com 3 Mic Audio Out
Com 2 Mic Key
MKR Antenna
1
A
2
B
3
C
4
D
5
E
6
F
7
H
8
J
9
K
10
L
11
M
12
N
13
P
14
R
15
S
16
T
17
U
18
V
19
W
20
X
21
Y
22
Z
J1 Bottom Connector
Ext. Marker Audio In
PA Activate
AUX Control Out
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
![](asset-12.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 2-10 Rev. 0, Sept. 2000
2.10 Post Installation Checkout
After wiring is complete, verify power is ONLY on pin 20 of the J1 (bottom connector),
and airframe ground on bottom connector pin Z. Failure to do so will cause serious inter-
nal damage and void the warranty.
2.11 Unit Installation
To install the KMA 28, gently slide the unit into the mounting rack until the hold-down
screw is engaged. While applying gentle pressure to the face of the unit, tighten the 3/32"
hex-head in the center of the unit until it is secure. DO NOT OVER TIGHTEN.
Warning: Do not over-tighten the lock down screw while installing the
unit in tray. Internal damage will result.
2.11.1 Operational Checkout
1. Apply power to the aircraft and avionics. Switch on the unit by pressing the volume
knob.
2. Plug headsets into the pilot, copilot, and occupied passenger positions.
3. Rotate the Mic Selector Switch to the Com 1 position.
4. Verify that the Com 1 button lights. Verify that the green transmit LED (Light Emit-
ting Diode) near the mic selector is not illuminated. If the LED is on, stop testing and
troubleshoot the microphone PTT installation.
5. Verify proper transmit and receive operation from the copilot position, noting that the
copilot PTT switch allows proper transmission on the selected transceiver.
6. Verify that pushing the COM 2 button causes the button to illuminate, and the Com 2
receiver to be heard. Verify operation on Com 1 from the pilot position.
7. Repeat for Com 2 and Com 3, (if installed).
8. Rotate the mic selector switch to the COM 1/2 position. Verify that the pilot commu-
nicates on Com 1 and the copilot on Com 2.
9. Rotate the mic selector switch to the COM 2/1 position. Verify that the pilot commu-
nicates on Com 2 and the copilot on Com 1.
10. Rotate the mic selector switch to the TEL position. Verify that the pilot headset is
connected to the cellular telephone system (if installed). Verify that by using the pilot
side PTT, the pilot can transmit on Com 1. The copilot has no transmit capability in
TEL mode.
11. Verify proper operation of all receiver sources by selecting them using the button.
Note that the button for the receiver sources stays in, and the button illuminates to
show which source is in use.
12. Push in the SPR button. Verify that all selected audio is heard in the cockpit speaker.
Verify that the audio mutes when the mic is keyed.
13. Verify that the LED in the lower right side illuminates when either push to talk is
keyed.
14. Verify proper Intercom system operation in the ALL, ISO and CREW modes (see Ta-
ble 3-1).
![](asset-13.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Page 2-11 Rev. 0, Sept. 2000
15. Verify that the audio selector panel system does not adversely affect any other aircraft
system by systematically switching the unit on and off, while monitoring the other
avionics and electrical equipment on the aircraft.
2.11.1.1 Marker Checkout
1. Connect a ramp generator at the antenna end of the marker coax. With the unit under
test in HI sensitivity, verify that a 160 µV, modulated 95% with 1300 Hz, signal will
illuminate the amber (M) marker light, and that marker audio is present in the head-
phones when the Marker Audio (MKR) push-button has been depressed. Select SPR
for speaker to verify marker audio availability on the cabin speaker. Verify that the
white (A) and blue (O) lights will illuminate within ± 3dB of the amber lamp, with
3000 HZ and 400 Hz applied, respectively.
2. Repeat with the unit in LOW sensitivity, with 430 µVolts applied.
3. Connect the marker antenna and verify proper operation.
2.11.2 Receiver Sensitivity
Although the KMA28 meets FAA TSO-C35d sensitivity specifications, the sensitivity of
the receiver has been adjusted to meet real world requirements (150µV and 430µV, soft).
This will usually eliminate the need for the avionics shop to reduce the sensitivity in the
field so as to prevent early detection of the marker beacons. If your particular installation
requires more or less sensitivity, see adjustment section 2.6, and figure 2-1.
2.12 Cellular Interface Checkout
When a wireless telecommunication system is installed and configured, a dial tone will
appear in the headset of the pilot when the mic selector is in the “Tel” position. In “ALL”
intercom mode, a dial tone will be heard whenever the copilot or passenger’s hook switch
is closed.
2.13 Final Inspection
Verify that the wiring is bundled away from all controls and no part of the installation in-
terferes with aircraft control operation. Move all controls through their full range while
examining the installation to see that no mechanical interference exists. Verify that the
cables are secured to the aircraft structure in accordance with good practices, with ade-
quate strain relief. Ensure that there are no kinks or sharp bends in the cables and coaxial
cables. Verify that the cables are not exposed to any sharp edges or rough surfaces, and
that all contact points are protected from abrasion.
Complete log book entry, FAA Form 337, weight and balance computation and other
documentation as required. Sample text for FAA Form 337, and instructions for continu-
ing airworthiness can be found in Appendix D.
Return completed warranty registration application.
![](asset-14.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 3-1 Rev. 0, Sept. 00
Section III KMA28 OPERATION
GENERAL INFORMATION
KMA28 controls
3.1 Audio Selector
Receiver audio is selected through two momentary and six latched, push-button, 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 will be in
the "out" position and remove that receiver from the audio.
3.1.1.1 Key “click”
The KMA28 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 re-
ceiver buttons for five seconds, and release. Repeat to defeat the click.
3.1.2 Speaker Amplifier
The "SPR" in the push-button section stands for speaker. This switch will place all se-
lected audio on the cockpit speaker when this switch is selected.
![](asset-15.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 3-2 Rev. 0, Sept. 00
3.1.3 Public Address (PA) Function
The KMA 28 has a public address capability when an optional external PA switch is in-
stalled. 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.
3.2 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 communi-
cation 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).
3.3 Microphone Selector
When the mic selector switch is in the Com 1 position, both pilot and copilot will be con-
nected 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 KMA28 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 KMA28 has an automatic selector mode. Audio from the selected transceiver is
automatically heard in the headsets and speaker. You can check this function by switch-
ing 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 KMA28 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 hav-
ing 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 se-
lection of Com audio.
![](asset-16.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 3-3 Rev. 0, Sept. 00
3.3.1 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 ei-
ther press the yoke mounted switch again, or turn the mic selector switch to the Com that
is active.
3.3.2 Split Mode
Turning the rotary switch to COM 1/COM 2 places the KMA28 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 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.
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.
3.3.2.1 Split Mode ICS
In split mode, the pilot and copilot are isolated from each other on the intercom, simulta-
neously using their respective radios. Depressing the ICS button in Split Mode will acti-
vate VOX intercom between the pilot and copilot positions. This permits intercommuni-
cation when desired between the crew. Pressing the ICS button again disables this crew
intercom function.
3.3.3 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
![](asset-17.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 3-4 Rev. 0, Sept. 00
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 Com-
mission (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
possible interface cables. These must be purchased separately, and are not for sale from
Honeywell.
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 22X/20X/18X
NEC960
NEC DT2000 Digital Phone
NOTE:
NOTE:NOTE:
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.
3.4 Intercom System
3.4.1 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.
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 ¼ inch of your lips,
preferably against them. It is also a good idea to keep the microphone out of a direct wind
![](asset-18.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 3-5 Rev. 0, Sept. 00
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 Micro-
phone 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.
3.4.2 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.
3.4.2.1 Mono headsets in Stereo Installation
All passenger headsets are connected in parallel. Therefore, if a monaural headset is
plugged in to a Stereo KMA28 installation, one channel will be shorted. Although no
damage to the unit will occur, all passengers will lose one channel.
3.4.2.2 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 pas-
sengers will hear copilot intercom and Entertainment 2. Neither will hear 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. Pas-
sengers can continue to communicate with themselves without interrupting the Crew and
also may listen to Entertainment 2.
Anytime the KMA28 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.
![](asset-19.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 3-6 Rev. 0, Sept. 00
3.4.2.3 Entertainment Input
The audio selector panel has provisions for two separate entertainment input devices.
They operate independently in the KMA28. The volume control does not affect music
level.
While in the ISO (Isolate) mode, the copilot will hear Entertainment 1 while the four pas-
sengers 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 be-
comes 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 pas-
sengers 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.
3.4.2.4 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 mu-
sic 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 but-
ton 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.
![](asset-1a.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 3-7 Rev. 0, Sept. 00
Table 3-1 Intercom Modes
Mode Pilot Hears Copilot Hears Passenger Hears Telephone Comments
Isolate A/C Radios
Pilot Sidetone
(during radio transmis-
sion)
Entertainment 1 is
Muted
Copilot 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 re-
ceive.
This mode allows the
pilot to communicate
without the others both-
ered by the conversa-
tions. Copilot and pas-
sengers 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
All 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 re-
ception as well as com-
municate on the inter-
com. Music and intercom
is muted during intercom
and radio communica-
tions
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 con-
centrate on flying, while
the passengers can
communicate amongst
themselves.
3.5 Marker Beacon Operation
The Marker Beacon Receiver uses visual and audio indicators to alert you when the air-
craft 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 ac-
tion is required to restore the audio in time for the next beacon.
3.6 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 mounted adjacent to the headset
jacks.
![](asset-1b.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 3-8 Rev. 0, Sept. 00
When the intercom is in ALL mode, the pilot can speak on the phone only if the mic se-
lector switch is in TEL position. All intercom positions will hear the telephone conversa-
tion. Anyone who places his or her switch into the “off-hook” 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 off-hook position will also have access to the phone, and all four passengers will
hear the conversation.
In ISO intercom mode, when the KMA28 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.
![](asset-1c.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Appendix ARev. 0, Sept. 00
Appendix A – Installation Drawings
6.32in (160.1 mm)
Cutout size for front mount installation 1.35 in
(34.29 mm)
Weight: 1.5 lb with tray and connectors ( .68 kg)
J1 (bottom)
J2 (top)
ZYXWVU TSRPNMLK JH FEDCB
22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2
A
1
Connector viewed from the rear
ZYXWVU TSRPNMLK JH FEDCB
22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2
A
1
Cutout size for rear mount installation 1.30 in
(33.02 mm)
6.2 in (152.7 mm)
Keying Pin
Keying Pin
![](asset-1d.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Appendix ARev. 0, Sept. 00
211
233
231
223133
111
123
113
6.37
6.28
C
0.35
0.60
1.31
0.65
1.25
5.25 0.80
0.65
0.75
0.11
6.95
Figure 4-1 Tray Dimensions in inches
![](asset-1e.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Appendix ARev. 0, Sept. 00
Top View
5.94 in
7.48 in
6.21 in
6.28
1.251.35
Figure 4-2 Unit External Dimensions in inches
![](asset-1f.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Appendix ARev. 0, Sept. 00
Figure 4-3 Tray Assembly Drawing
![](asset-20.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Appendix B Rev. 0, Sept. 2000
Appendix B Bottom Connector Interconnect
Com 1 Audio Hi
Com 1 Mic Key
Com 1 Lo
Communications
Transceiver #1
Communications
Transceiver #2
Nav 1 Audio Hi
NAV 1 Audio Lo
VHF Nav 1
Nav 2 Audio Hi
Nav 2 Audio Lo
VHF Nav 2
DME Audio Hi
DME Audio Lo
DME Receiver
Com 1 SPR Load
Com 2 SPR Load
Unswitched Input #1 Hi
Unswitched Audio Lo
Unswitched Audio #1
Unswitched Input #2 Hi
Unswitched Audio Lo
Unswitched Audio #2
Pilot Mic Audio Hi
Pilot Mic PTT
Pilot Mic Lo
Ext. Marker Lamp (Blue)
C
5
4
2
Ext. Marker Lamp (White)
Ext. Marker Lamp (Amber)
MM Sense Output
MKR Ant.
B
A
White Lamp Output
Blue Lamp Output
Amber Lamp
MM Sense
RG-400A/U Coax
PA Mute Trigger
F
D
E
18
20
1
Z
W
22
28 Volt Lights Hi
14 V Lights Hi
Lights Lo
Ground
Airframe Ground
2A (14VDC)
3A (28VDC)
11-33 VDC
9
P
R
Com 1 Mic Audio Hi
Com 2 Audio Hi
Com 2 Mic Key
Com 2 Lo
10
H
V
Com 2 Mic Audio Hi
12
13
6
14
N
19
L
Com 1 Spr Load
Com 1 Spr Load
Com 2 Spr Load
Com 2 Spr Load 16
M
T
17
Speaker Hi
Speaker Lo
3
Pilot Phones (L)
Pilot Phones (R)
Pilot Phones Lo
8
Y
To Pin 1
Top Conn.
Communications
Transceiver #3
J
K
15
Com 3 Audio Hi
Com 3 Mic Audio Hi
Com 3 Lo
Com 3 Mic Key
Mkr Audio In Hi
Mkr Audio In Lo
Ext. Mkr Audio 21
ADF Audio Hi
ADF Audio Lo
ADF Receiver S
AUX Audio Hi
AUX Audio Lo
AUX Audio 11
Notes:
1. Pins 7, U, and X not used.
2. All shields should be grounded
at audio panel only.
Other end remains floating.
3. Speaker and Pilot Headphone
ground returns MUST be kept
separate and connected to pin 22.
4. All Power, and Ground wires must be #18 gage wire
Lighting #22 AWG, other wires minumum #24 AWG
5. Pilot mic and headphone jacks
must be isolated from ground.
6. Pin 20 connected through a 3 A breaker.
7. PA Mute is a TTL level logic output
that is pulled low when PTT active.
8. Speaker loads may be reqired on some
transceivers. Consult manufacturer's information.
9. 28V installations require a 3 A breaker.
10. Interface information shown for AirCell phone only.
Ground shield at J3 only.
11. All shielded wires must be MIL 22750 or 27500.
12. Connect pilot headphone (L) to top connector, Pin 1,
using 3-conductor wire.
13. Key pin between pin 7 and 8.
Ext. Marker Annunciator
Note 10
Cellphone A
Cellphone B
V
W
K
AirCell
J3
Pilot PTT
See Note 4, 9
See Note 7
See Note 4, 9
See Note 3
See Note 8
See Note 12
Bottom Connector, J1
![](asset-21.png)
Bendix/King
KMA28
Audio Amplifier/Intercom/Marker Beacon Receiver
006-10565-0000 Appendix C Rev. 0, Sept. 2000
Appendix C Top Connector Interconnect
U
19
10
W
20
X
21
Y
22
Z
1
4
D
16
15
TNotes:
2
3
B
Copilot Phones (L)
Copilot Phones (R)
Copilot Phones Lo
Pilot Phones (L) -see bottom connector.
12
11
N
Pass. Phones (L)
Pass Phones (R)
Pass. Phones Lo
Pass. 1 Mic Jack
Pass. Mic Lo
Pass. Mic Hi
Pass. 1 PhonesJack
5
EPass. 2 Mic Jack
Pass. Mic Lo
Pass. Mic Hi Pass. 2 Phones Jack
6
FPass. 3 Mic Jack
Pass. Mic Lo
Pass. Mic Hi Pass. 3 Phones Jack
7
HPass. 4 Mic Jack
Pass. Mic Lo
Pass. Mic Hi Pass. 4 Phones Jack
8
9
K
Copilot Mic Audio
Copilot Mic PTT
Copilot Mic Lo
Copilot Mic Jack
Ent. #1 Audio (L)
Ent. #1 Audio (R)
Ent. #1 Audio Lo
Ent. #1 Input
Ent. #2 Input
14
13
R
LCopilot hook switch
V
VOX Override
Ent. #2 Mute
M
Passenger Hook Switches
Reserved
Note 3
Notes 2, 4
Note 7
Ent. #2 Audio (L)
Ent. #2 Audio (R)
Ent. #2 Audio Lo
Swap
J2 TOP CONNECTOR
1. Pin C is reserved
2. All shields should be grounded at audio panel only.
Other end remains floating.
3. Reserved
4. All phone and mic jacks must be floating from ground.
5. Keying between pin 4 & 5.
6. All should be MIL 22750 or 27500.
Minimum #24 AWG conductors
7. Passenger hook switches to be located at positions
where phone access is desired.
Grounding of any switch causes all passengers to be
heard on the cellphone.
8. Music 1 is heard in pilot and copilot positions only.
Music 2 is heard in passenger positions only.
9. Grounding pin U defeats IntelliVox and opens all microphones.
Usually not connected
10. Grounding pin 18 places units into PA mode.
11. Pin A is pulled low when AUX button pushed.
Note 9
18 PA Mode Note 10
ANote 11
Control Output
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
![](asset-22.png)
006-10565-0000 Appendix D Rev. 0, Sept. 2000
Appendix D- Instructions for FAA Form 337 and Continuing
Airworthiness
7.1 Instructions for FAA Form 337
One method of airworthiness approval is through an FAA Form 337, Major Repair and Alteration (Air-
frame, Powerplant, Propeller, or Appliance) In the case of the KMA 28, you may use the following text as
a guide.
Installed audio selector and 6-place intercom, Honeywell KMA 28, part number 066-01176-
(XXXX) in ( location ) at station . Installed per AC43.13-2, Chapter 2, paragraph 23 (In-
strument Panel Mounting). Installed per Honeywell Installation Operators Manual p/n 006-10565-
(____), revision (), dated ( ).
This unit is FAA-Approved under TSO C50c for audio amplifiers, TSO C35d for Marker Beacon
Receivers, and meets appropriate environmental qualifications outlined in RTCA DO-160B as ap-
propriate or this aircraft.
Interface to existing aircraft radios in accordance with installation manual and in compliance with
practices listed in AC43.13-2, Chapter 2. All wires are Mil-Spec 22759 or 27500. Connection to
aircraft dimmer bus is ____________________. Power is supplied to the unit through a __A cir-
cuit breaker (type and part number), and total electrical load does not exceed % of the elec-
trical system capacity with the KMA 28 added.
Aircraft equipment list, weights and balance amended. Compass compensation checked. A copy of
the operation instructions, contained in Honeywell document 006-10565-(____), revision ( ), dated
( ), is placed in the aircraft records. All work accomplished listed on Work Order .
Instructions for Continuing Airworthiness,
Sample ICA Checklist for KMA28:
Section Item Information
1 Introduction Installation of audio control panel with integrated marker beacon receiver and
intercommunications system.
2 Description Installation as described in manufacturer’s installation manual referenced on
FAA Form 337, including interface with other avionics audio as required.
3 Controls See installation and operator’s guide referenced on FAA Form 337.
4 Servicing None Required
5 Maintenance Instructions On Condition, no special instructions
6 Troubleshooting In the event of a unit problem, place the unit into “OFF/EMG” mode. This
allows pilot communications using COM 1. Follow checkout instructions in the
installation manual referenced on the FAA Form 337. For a specific unit fault,
contact the manufacturer at 1-800-257-0726 for special instructions.
7 Removal and replacement informa-
tion
Removal: Using a 3/32” Allen-head wrench, carefully unscrew the locking
screw located in the center of the unit. While turning the wrench CCW, gently
pull on the EDGES of the bezel until the unit is free from the mounting tray.
Installation: Engage the locking screw at the back. Turn the locking screw CW,
while applying slight pressure to the edges of the bezel. Do not over tighten!
8 Diagrams Not applicable
9 Special Inspection Requirements Not Applicable
10 Protective Treatments Not Applicable
11 Structural Data Not Applicable
12 Special Tools None
13 Not Applicable Not Applicable
14 Recommended Overhaul Periods None
15 Airworthiness Limitations Not Applicable
16 Revision To be determined by installer
![](asset-23.png)
006-10565-0000 Appendix E Rev. 0, Sept. 2000
Appendix E RTCA DO160C (EUROCAE ED-14) Environmental
Qualification Form
Audio Selector Panel/Intercom/Marker Beacon Receiver
Part Number: 7000M-S
FAA TSO Number: C50c, C35d Class A, JTSO 2C35d and JTSO C50c
Manufacturer: PS Engineering Incorporated 9800 Martel Road Lenoir City TN 37772
Conditions Section Conducted Tests
Temperature and Altitude
Low Temperature
High Temperature
In-flight Loss of Cooling
Altitude
Decompression
Overpressure
4.0
4.5.1
4.5.2
4.5.4
4.6.1
4.6.2
4.6.3
Equipment tested to CAT A1 & D1
-55° C Storage, -15°C Low Operating (A1)
+85°C Storage, +70°C High Operating
Not Applicable, no cooling required
50,000’ unpressurized
Not Applicable
Not Applicable
Temperature variation 5.2 Equipment tested to Category C
Humidity 6.0 Equipment tested to Category A
Shock 7.0 Equipment tested to Operational test only
Operational 7.2 Equipment tested to Operational test only
Crash Safety 7.3 Equipment tested to Operational test only
Vibration 8.0 Equipment tested to Category M & N
Explosion 9.0 Category X, not tested
Waterproofness 10.0 Category X, not tested
Fluids Susceptibility 11.0 Category X, not tested
Sand and Dust 12.0 Category X, not tested
Fungus 13.0 Category X, not tested
Salt Spray 14.0 Category X, not tested
Magnetic Effect 15.0 Equipment tested to Category Z
Power input 16.0 Equipment tested to Category B
Voltage Spike 17.0 Equipment tested to Category B
Audio Frequency Susceptibil-
ity
18.0 Equipment tested to Category B
Induced Frequency Suscepti-
bility
19.0 Equipment tested to Category B
Radio Frequency Susceptibil-
ity
20.0 Equipment tested to Category T
Radio Frequency Emission 21.0 Equipment tested to Category B
Lightning Induced Transient
Susceptibility
22.0 Equipment tested to Category K
Lightning Direct Effects 23.0 Category X, not tested
Icing 24.0 Category X, not tested