Honeywell Stereo Amplifier KMA28 User Manual

Installation and Operation Manual  
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.  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
2.11.1  
2.11.2  
2.12  
OPERATIONAL CHECKOUT ......................................................................................2-10  
RECEIVER SENSITIVITY...........................................................................................2-11  
CELLULAR INTERFACE CHECKOUT ...........................................................................2-11  
FINAL INSPECTION.......................................................................................................2-11  
2.13  
3 SECTION III KMA28 OPERATION .................................................................................3-1  
3.1  
AUDIO SELECTOR ............................................................................................................3-1  
SPEAKER AMPLIFIER...................................................................................................3-1  
PUBLIC ADDRESS (PA) FUNCTION .............................................................................3-2  
POWER SWITCH /EMERGENCY (EMG) OPERATION.....................................................3-2  
MICROPHONE SELECTOR................................................................................................3-2  
SWAP MODE (SWITCH FROM COM 1 TO COM 2 REMOTELY)......................................3-3  
SPLIT MODE................................................................................................................3-3  
TELEPHONE MODE......................................................................................................3-3  
INTERCOM SYSTEM .........................................................................................................3-4  
INTELLIVOX® VOX-SQUELCH....................................................................................3-4  
VOLUME CONTROL.....................................................................................................3-5  
MARKER BEACON OPERATION ......................................................................................3-7  
TELEPHONE OPERATION (IF EQUIPPED WITH APPROVED SYSTEM).............................3-7  
3.1.2  
3.1.3  
3.2  
3.3  
3.3.1  
3.3.2  
3.3.3  
3.4  
3.4.1  
3.4.2  
3.5  
3.6  
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  
006-10565-0000  
Page ii  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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.  
IntelliVox® is a trademark of PS Engineering, Incorporated, and used with their permission  
006-10565-0000  
Page 1-1  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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.  
006-10565-0000  
Page 1-2  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
1.5  
SPECIFICATIONS  
TSO COMPLIANCE  
C35d, Class A  
Marker Beacon:  
Audio Selector/Intercom:  
APPLICABLE DOCUMENTS:  
C50c, Class A  
RTCA/DO-214  
RTCA/DO-143  
RTCA/DO-160C  
RTCA/DO-178B  
ENVIRONMENTAL Qualifications:  
Temperature Range:  
Operating:  
A1D1/CA(MN)XXXXXXBBBBTBKXX  
-15º C to +55ºC  
Storage:  
-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)  
1.5 lb. (0.54 kg)  
WEIGHT (With Rack & Connectors):  
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:  
Input Isolation:  
Speaker Muting:  
510  
-60 dB (min.)  
-60 dB (min.)  
Speaker Output (into 4 ) with no clipping  
14 VDC:  
3 Watts (min.)  
10 Watts (min.)  
28 VDC:  
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)  
4 Ω  
Speaker Impedance:  
Headphone Impedance:  
Headphone Output:  
150 - 1000 Ω  
38 mW each headset, no clipping <1% THD  
70 mW each headset with < 10% THD into 150Ω  
150 - 600 Ω  
Microphone Impedance:  
006-10565-0000  
Page 1-3  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
Intercom Specifications  
Intercom Positions:  
Music Inputs:  
Music Muting:  
Distortion:  
6 places (with individual IntelliVOX® circuits)  
2 (Stereo)  
>-30 dB "Soft Mute" when Com or intercom active.  
<1% THD @ 38 mW into 150Ω  
<10% THD @ 70mW into 150 Ω  
300 Hz - 6000 Hz  
Mic Freq. Response, 3 dB:  
Music Freq. Response, 3 dB:  
100 Hz - 18kHz  
MARKER BEACON RECEIVER  
Frequency:  
Sensitivity:  
Low:  
75 MHz Crystal Controlled  
Capable of:  
1000 µVolts (Hard)  
High:  
200 µVolts (Hard)  
(preset at factory for field application)  
Selectivity:  
-6 dB at ±10 kHz  
-40 dB at ±120 kHz  
External Lamp Output:  
MM Sense:  
9.0 (±2.5 unloaded, at maximum brightness) VDC posi-  
tive when active, max. current 125 mA  
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  
Top Molex Connector Shell w/key, 44 pin, key 4/5  
1
1
071-00164-0001  
120-425-4402  
Bottom Molex Connector Shell w/key, 44 pin, key 7/8  
Gold Plated Crimp Pins  
4 40 X 7/16 screw w/nyl patch  
Grounding strap  
6-32 X 3/4 screw php  
6-32 Nut Flat  
6-32 Lock Nut  
Cable Clamp  
#6-32 x ½” FHP screw  
#6-32 Clip Nut  
1
88  
4
1
2
2
2
1
6
120-425-4400  
425-001-0002  
475-440-0007  
430-007-0001  
475-632-0038  
475-632-0003  
475-632-0004  
625-001-0002  
475-632-0012  
475-630-0002  
6
The KMA 28 install rack may be purchased separately under part number 071-00164-0001.  
006-10565-0000  
Page 1-4  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
1.7  
EQUIPMENT REQUIRED BUT NOT SUPPLIED  
Circuit Breaker: 1 ea. 3 amp  
a)  
b)  
c)  
d)  
e)  
f)  
Speaker, 4 Ω  
Headphone Jacks (Stereo, as Required)  
Microphone Jacks (as Required)  
Headphones, 150 (Stereo), up to 6 as required  
Microphones, up to 6 as required  
g)  
h)  
Marker Antenna (75 MHz, VSWR <1:1.5, 50 ohm, and cable (RG400 R/U)  
Interconnect Wiring  
1.8  
LICENSE REQUIREMENTS  
None  
006-10565-0000  
Page 1-5  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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.  
006-10565-0000  
Page 2-1  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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  
006-10565-0000  
Page 2-2  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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.  
006-10565-0000  
Page 2-3  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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 510inputs 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  
2.4.10.1.1Stereo 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  
006-10565-0000  
Page 2-4  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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.  
2.4.10.1.2Entertainment 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.  
2.4.10.1.3Entertainment 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  
006-10565-0000  
Page 2-5  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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.  
006-10565-0000  
Page 2-6  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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  
MKR Low Sense  
CW Decrease Sens.  
Passenger Volume  
CCW Increases  
KMA28 adjustment holes  
Not used  
Speaker Volume  
CW-Increase  
Marker Audio  
CW Decrease Volume  
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:  
Itisprobable 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  
006-10565-0000  
Page 2-7  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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.  
006-10565-0000  
Page 2-8  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
2.9 KMA 28 Pin Assignments  
J2 Top Connector  
J1 Bottom Connector  
Pilot Phone Audio Hi (Left)  
Chassis Ground  
1
A
2
B
3
C
4
D
5
E
6
F
7
H
8
J
9
K
1
A
2
B
3
C
4
D
5
E
6
F
7
H
8
J
9
K
MKR Coax Lo  
MM Sense Output  
MKR Antenna  
AUX Control Out  
Copilot Phone Audio (Lt)  
Copilot Phone Audio Lo  
Copilot Phone Audio (Rt)  
Pilot Headphones  
White Lamp Output  
Pass 1 Mic Audio Hi  
Pass 1 Mic Audio Lo  
Amber Lamp Out  
14 V Light Hi  
Pass 2 Mic Audio Hi  
Pass 2 Mic Audio Lo  
Pass 3 Mic Audio Hi  
Pass 3 Mic Audio Lo  
Pass 4 Mic Audio Hi  
Pass 4 Mic Audio Lo  
Copilot Mic Audio Hi  
Blue Lamp Out  
Light Lo  
DME Audio Hi  
28V Lights Hi  
Com 2 Mic Audio Out  
Pilot Mic Audio Hi In  
Com 3 Audio Hi  
Com 1 Audio Hi  
Copilot Mic Key  
Copilot Mic Audio Lo  
Swap Switch  
Com 3 Mic Audio Out  
10  
L
Com 2 Audio Hi  
Com 1 Spkr Load  
AUX Audio Input Hi  
10  
L
Copilot Cellphone Off Hook  
Passenger Headphone Audio (R)  
11  
M
12  
N
13  
P
14  
R
15  
S
16  
T
17  
U
18  
V
11  
M
12  
N
13  
P
14  
R
15  
S
16  
T
17  
U
18  
V
Pass Cellphone Off Hook  
Com 2 SPKR Load  
Nav 1 Audio Hi  
Cellphone tip  
Passenger Headphone Audio (L)  
Passenger Headphone Audio Lo  
Entertainment #2 In (R)  
Nav 2 Audio Hi  
Com 1 Mic Audio Out  
Cellphone ring  
Entertainment #2 In (L)  
Entertainment # 2 Lo  
Entertainment #1 In (R)  
Com 1 Mic Key  
Com 3 Mic Key  
ADF Audio Hi  
Entertainment #1 In (L)  
Com 2 SPKR load  
Unswitched Audio In #1  
Unswitched Audio In #2  
Entertainment #1 Lo  
Ground  
IntelliVOX Over ride  
PA Mute  
Com 2 Mic Key  
PA Activate  
Ent 2 Mute  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Com 1 SPKR load  
Cabin Spkr Out  
19  
W
20  
X
21  
Y
19  
W
20  
X
21  
Y
Aircraft Power 11-33 VDC  
Ext. Marker Audio In  
Reserved  
Reserved  
Pilot Mic Key  
Cabin Spkr Lo  
22  
Z
22  
Z
Aircraft Ground  
Reserved  
006-10565-0000  
Page 2-9  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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).  
006-10565-0000  
Page 2-10  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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.  
006-10565-0000  
Page 2-11  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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.  
006-10565-0000  
3-1  
Rev. 0, Sept. 00  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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.  
006-10565-0000  
3-2  
Rev. 0, Sept. 00  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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  
006-10565-0000  
3-3  
Rev. 0, Sept. 00  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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:  
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  
006-10565-0000  
3-4  
Rev. 0, Sept. 00  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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.  
006-10565-0000  
3-5  
Rev. 0, Sept. 00  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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.  
006-10565-0000  
3-6  
Rev. 0, Sept. 00  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
Table 3-1 Intercom Modes  
Mode  
Pilot Hears  
A/C Radios  
Pilot Sidetone  
Copilot Hears  
Passenger Hears  
Telephone  
Comments  
Copilot and passenger Passenger and Copilot “Phone Booth” mode  
intercom  
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  
Isolate  
intercom  
Pilot has exclusive use of  
the telephone.  
Entertainment #1  
Entertainment #2  
(during radio transmis-  
sion)  
In TEL, Pilot connected to  
Com 1 for PTT TX and re-  
ceive.  
Entertainment  
Muted  
1
is  
Pilot  
Copilot  
Passengers  
Pilot  
All have access to phone This mode allows all on  
through Hook Switch. Pilot board to hear radio re-  
All  
Copilot  
Pilot  
access through TEL switch.  
ception as well as com-  
municate on the inter-  
com. Music and intercom  
is muted during intercom  
and radio communica-  
tions  
A/C Radio  
Passengers  
A/C Radio  
Passengers  
Entertainment #1  
Copilot  
All hear telephone audio.  
A/C Radio  
Entertainment #2  
Entertainment #1  
Pilot  
Copilot  
Passengers  
Pilot and copilot don’t have This mode allows the  
phone access, unless mic pilot and copilot to con-  
sel in TEL. Passengers centrate on flying, while  
Crew  
Copilot  
Pilot  
Entertainment #2  
have phone through Hook the  
Switch, Passengers hear communicate  
phone audio. themselves.  
passengers  
can  
A/C Radio  
Entertainment #1  
A/C Radio  
Entertainment #1  
amongst  
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.  
006-10565-0000  
3-7  
Rev. 0, Sept. 00  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
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.  
006-10565-0000  
3-8  
Rev. 0, Sept. 00  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
Appendix A – Installation Drawings  
1.35 in  
(34.29 mm)  
Cutout size for front mount installation  
6.32in (160.1 mm)  
Cutout size for rear mount installation  
1.30 in  
(33.02 mm)  
6.2 in (152.7 mm)  
Weight: 1.5 lb with tray and connectors ( .68 kg)  
Connector viewed from the rear  
Z Y X W V U T S R P N M L K J H F E D C B A  
J2 (top)  
22 21 20 19 18 17 16 15 14 13 12 11 10  
9
8
7
6 5 4 3  
2
1
Keying Pin  
Z Y X W V U T S R P N M L K J H F E D C B A  
J1 (bottom)  
22 21 20 19 18 17 16 15 14 13 12 11 10  
9
8
7
6 5 4 3  
2
1
Keying Pin  
006-10565-0000  
Appendix A  
Rev. 0, Sept. 00  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
233  
211  
231  
6.37  
6.95  
111  
123  
113  
133  
223  
6.28  
0.75  
0.60  
0.11  
1.31  
C
0.65  
0.35  
0.65  
1.25  
5.25  
0.80  
Figure 4-1 Tray Dimensions in inches  
006-10565-0000  
Appendix A  
Rev. 0, Sept. 00  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
6.21 in  
Top View  
7.48 in  
5.94 in  
6.28  
1.35  
1.25  
Figure 4-2 Unit External Dimensions in inches  
006-10565-0000  
Appendix A  
Rev. 0, Sept. 00  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
Figure 4-3 Tray Assembly Drawing  
006-10565-0000  
Appendix A  
Rev. 0, Sept. 00  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
Appendix B Bottom Connector Interconnect  
Com 1 Audio Hi  
9
Bottom Connector, J1  
Notes:  
1. Pins 7, U, and X not used.  
2. All shields should be grounded  
at audio panel only.  
Communications  
Transceiver #1  
Com 1 Lo  
Com 1 Mic Audio Hi  
Com 1 Mic Key  
P
R
Com 1 Spr Load  
Com 1 Spr Load  
19  
L
Com 1 SPR Load  
Other end remains floating.  
See Note 8  
3. Speaker and Pilot Headphone  
Com 2 Audio Hi  
10  
Communications  
Transceiver #2  
Com 2 Lo  
ground returns MUST be kept  
Com 2 Mic Audio Hi  
Com 2 Mic Key  
H
V
16  
M
J
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  
Com 2 Spr Load  
Com 2 Spr Load  
Com 2 SPR Load  
Com 3 Audio Hi  
Com 3 Lo  
must be isolated from ground.  
Communications  
Transceiver #3  
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.  
Com 3 Mic Audio Hi  
Com 3 Mic Key  
K
15  
J3  
Cellphone A  
Cellphone B  
V
14  
N
Note 10  
W
K
Nav 1 Audio Hi  
NAV 1 Audio Lo  
12  
VHF Nav 1  
11. All shielded wires must be MIL 22750 or 27500.  
12. Connect pilot headphone (L) to top connector, Pin 1,  
using 3-conductor wire.  
Nav 2 Audio Hi  
Nav 2 Audio Lo  
13  
21  
S
VHF Nav 2  
Mkr Audio In Hi  
Mkr Audio In Lo  
Ext. Mkr Audio  
ADF Receiver  
13. Key pin between pin 7 and 8.  
ADF Audio Hi  
ADF Audio Lo  
DME Audio Hi  
DME Audio Lo  
6
DME Receiver  
AUX Audio Hi  
AUX Audio Lo  
11  
AUX Audio  
Unswitched Audio #1  
Unswitched Audio #2  
Unswitched Input #1 Hi  
Unswitched Audio Lo  
T
Unswitched Input #2 Hi  
Unswitched Audio Lo  
17  
Pilot Mic Audio Hi  
8
Y
Pilot Mic PTT  
Pilot Mic Lo  
Pilot Phones (L)  
Pilot Phones (R)  
Pilot Phones Lo  
Pilot PTT  
To Pin 1  
Top Conn.  
See Note 12  
3
Speaker Hi  
Speaker Lo  
W
See Note 3  
22  
Ext. Marker Lamp (White)  
C
5
4
2
White Lamp Output  
Ext. Marker Lamp (Blue)  
Ext. Marker Lamp (Amber)  
Blue Lamp Output  
Amber Lamp  
MM Sense  
MM Sense Output  
MKR Ant.  
RG-400A/U Coax  
B
A
F
D
E
28 Volt Lights Hi  
14 V Lights Hi  
Lights Lo  
See Note 7  
PA Mute Trigger  
18  
11-33 VDC  
20  
2A (14VDC)  
3A (28VDC)  
See Note 4, 9  
Ground  
See Note 4, 9  
1
Z
Airframe Ground  
006-10565-0000  
Appendix B  
Rev. 0, Sept. 2000  
 
Bendix/King  
KMA28  
Audio Amplifier/Intercom/Marker Beacon Receiver  
Appendix C Top Connector Interconnect  
J2 TOP CONNECTOR  
Pilot Phones (L) -see bottom connector.  
1
2
3
B
Copilot Phones (L)  
Copilot Phones (R)  
Copilot Phones Lo  
Pass. Phones (L)  
Pass Phones (R)  
Pass. Phones Lo  
12  
11  
N
Pass. 1 PhonesJack  
Pass. Mic Hi  
Pass. Mic Lo  
4
D
Pass. 1 Mic Jack  
Pass. 2 Mic Jack  
Pass. Mic Hi  
Pass. Mic Lo  
5
E
Pass. 2 Phones Jack  
Notes 2, 4  
Pass. Mic Hi  
Pass. Mic Lo  
6
F
Pass. 3 Phones Jack  
Pass. 3 Mic Jack  
Pass. 4 Mic Jack  
Pass. Mic Hi  
Pass. Mic Lo  
7
H
Pass. 4 Phones Jack  
Copilot Mic Audio  
8
9
K
Copilot Mic Jack  
Copilot Mic PTT  
Copilot Mic Lo  
Ent. #1 Audio (L)  
Ent. #1 Audio (R)  
Ent. #1 Audio Lo  
16  
15  
T
14  
13  
R
Ent. #1 Input  
Notes:  
1. Pin C is reserved  
Ent. #2 Audio (L)  
2. All shields should be grounded at audio panel only.  
Other end remains floating.  
Ent. #2 Input  
Ent. #2 Audio (R)  
Ent. #2 Audio Lo  
3. Reserved  
Swap  
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.  
10  
18  
L
Note 10  
PA Mode  
Copilot hook switch  
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  
Note 9  
U
V
VOX Override  
Ent. #2 Mute  
Note 7  
10. Grounding pin 18 places units into PA mode.  
11. Pin A is pulled low when AUX button pushed.  
M
Passenger Hook Switches  
Reserved  
19  
W
Reserved  
Reserved  
20  
X
21  
Y
22  
Z
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Note 3  
A
Control Output Note 11  
006-10565-0000  
Appendix C  
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  
trical system capacity with the KMA 28 added.  
% of the elec-  
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  
Description  
Installation of audio control panel with integrated marker beacon receiver and  
intercommunications system.  
Installation as described in manufacturer’s installation manual referenced on  
FAA Form 337, including interface with other avionics audio as required.  
See installation and operator’s guide referenced on FAA Form 337.  
None Required  
2
3
4
5
6
Controls  
Servicing  
Maintenance Instructions  
Troubleshooting  
On Condition, no special instructions  
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.  
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!  
Not applicable  
7
Removal and replacement informa-  
tion  
8
Diagrams  
9
Special Inspection Requirements  
Protective Treatments  
Structural Data  
Special Tools  
Not Applicable  
Recommended Overhaul Periods  
Airworthiness Limitations  
Revision  
Not Applicable  
Not Applicable  
Not Applicable  
None  
Not Applicable  
None  
Not Applicable  
To be determined by installer  
10  
11  
12  
13  
14  
15  
16  
006-10565-0000  
Appendix D  
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  
Temperature and Altitude  
Low Temperature  
High Temperature  
In-flight Loss of Cooling  
Altitude  
Section  
4.0  
Conducted Tests  
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  
4.5.1  
4.5.2  
4.5.4  
4.6.1  
4.6.2  
4.6.3  
Decompression  
Overpressure  
Not Applicable  
Not Applicable  
Temperature variation  
Humidity  
Shock  
Operational  
Crash Safety  
5.2  
6.0  
7.0  
7.2  
7.3  
Equipment tested to Category C  
Equipment tested to Category A  
Equipment tested to Operational test only  
Equipment tested to Operational test only  
Equipment tested to Operational test only  
Equipment tested to Category M & N  
Category X, not tested  
Vibration  
Explosion  
8.0  
9.0  
Waterproofness  
Fluids Susceptibility  
Sand and Dust  
Fungus  
Salt Spray  
Magnetic Effect  
Power input  
Voltage Spike  
Audio Frequency Susceptibil-  
ity  
10.0  
11.0  
12.0  
13.0  
14.0  
15.0  
16.0  
17.0  
18.0  
Category X, not tested  
Category X, not tested  
Category X, not tested  
Category X, not tested  
Category X, not tested  
Equipment tested to Category Z  
Equipment tested to Category B  
Equipment tested to Category B  
Equipment tested to Category B  
Induced Frequency Suscepti-  
bility  
Radio Frequency Susceptibil-  
ity  
19.0  
20.0  
Equipment tested to Category B  
Equipment tested to Category T  
Radio Frequency Emission  
Lightning Induced Transient  
Susceptibility  
21.0  
22.0  
Equipment tested to Category B  
Equipment tested to Category K  
Lightning Direct Effects  
Icing  
23.0  
24.0  
Category X, not tested  
Category X, not tested  
006-10565-0000  
Appendix E  
Rev. 0, Sept. 2000  
 

Grandstream Networks IP Phone GXP1100 1105 User Manual
Grizzly Sander G1600 User Manual
Hamilton Beach Slow Cooker 33351 User Manual
Honeywell Digital Camera VDC 350PIV V User Manual
Hotpoint Washer WMFG 631 User Manual
HP Hewlett Packard Computer Hardware D300 DT User Manual
HP Hewlett Packard Server RP7400 User Manual
Hunter Fan Outdoor Ceiling Fan 59009 User Manual
Hyundai Car Satellite TV System H CDM8010 User Manual
iHome Cell Phone IB967 User Manual