Axnes Polycon MP20-00U, Polycon MP20-01U, Polycon MP20-02DB-414 Installation And Operation Manual

Axnes Aviation AS

Polycon MP20 Series

Hand Held Radio

Installation and Operation

Document number:

AX-PSB-UMAN-0027

Revision:

Issue E

Date:

2015-03-05

Axnes Aviation AS

Document number

Revision

Date

AX-PSB-UMAN-0027

Issue E

2015-03-05

Page ii

Revision history

Revision

Date

Description

List of effective pages

Issue A

2011-06-30

First release of Installation
and Operation manual.
Replaces Operation manual
PUBL041-00 Issue 3

New document

Issue B

2011-09-07

Edit 1.6.3. Headset interface

1-6 ,1-7,1-8

Issue C

2011-12-05

Corrected date and issue
statement on first page and
all footers

First page and all footers

Issue D

2012-07-09

Added MP20-02DB-456
Updated for SW version 3

Page 1-5
Section 2
Section 3

Issue E

2015-03-05

Document title change
Added MP20-01U in text and

removed p/n list (table 1-1).
Charge time changed to 2-3H
Interchanged TX and RX

frequencies.
Channel separation corrected

to 25KHz only.
Added colour codes.

Front page
Page 1-5

Page 1-6: Charge time
Page 1-6: Frequency

Page 1-7: UHF xx frequency
Page 1-7: Channel separation

Page 1-7: Colour

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Page iii

Table of contents

SECTION 1: GENERAL INFORMATION ................................................................................. 1-1

1.1 Introduction .......................................................................................................... 1-1

1.2 Mechanical description ......................................................................................... 1-2

1.3 Connectors and Control Functions ....................................................................... 1-3

1.4 Electrical and functional description ..................................................................... 1-4

1.5 Identification of article ........................................................................................... 1-5

1.6 Technical data ................................................................................................ ...... 1-6

1.6.1 Operation ...................................................................................................... 1-6

1.6.2 Power supply ................................................................................................ 1-6

1.6.3 Headset interface .......................................................................................... 1-6

1.6.4 Helmet/headset Connectors .......................................................................... 1-7

1.6.5 Radio characteristics ..................................................................................... 1-7

1.6.6 Dimensions ................................................................................................... 1-7

1.6.7 Material ......................................................................................................... 1-7

1.7 Type approvals and records ................................................................................. 1-8

1.7.1 Type approvals.............................................................................................. 1-8

1.7.2 Type Records ................................................................................................ 1-8

1.8 Accessories .......................................................................................................... 1-8

SECTION 2: INSTALLATION .................................................................................................. 2-1

2.1 General ................................................................................................................ 2-1

2.2 Inspection before installation ................................................................................ 2-1

2.3 Recommended maintenance ................................................................................ 2-1

2.4 Mechanical installation ......................................................................................... 2-2

2.5 Installation wiring consideration ............................................................................ 2-2

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2.6 Dimensions Polycon MP20 series hand held radio ............................................... 2-2

2.7 Location of connectors and pin assignment .......................................................... 2-3

2.7.1 Helmet/headset connection pin assignment .................................................. 2-3

2.8 Microphone compatibility ...................................................................................... 2-3

2.9 Post installation calibration ................................................................................... 2-4

SECTION 3: OPERATION ...................................................................................................... 3-1

3.1 MP20 series charging ........................................................................................... 3-1

3.2 Power Up/Down Sequence .................................................................................. 3-1

3.3 Change channel ................................................................................................... 3-2

3.4 Walkie-Talkie mode .............................................................................................. 3-2

3.5 Helmet/Headset connection ................................................................ ................. 3-2

3.6 NIVOX/Push to Talk (PTT) Operation ................................................................... 3-3

3.7 Person to Person / Casualty Communication mode ............................................. 3-3

3.8 Display orientation ................................................................................................ 3-4

3.9 Output Power Settings ......................................................................................... 3-4

3.10 Pressure Equalizing Actuator ............................................................................... 3-5

3.11 Default Settings .................................................................................................... 3-5

3.11.1 Select NIVOX or PTT default. ........................................................................ 3-5

3.11.2 Squelch ......................................................................................................... 3-6

3.11.3 Automatic Gain Control (AGC) ...................................................................... 3-6

3.11.4 Analogue Trigger Level (NIVOX Threshold) .................................................. 3-6

APPENDIX A CALIBRATION PARAMETERS ................................ ...................................... A

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Section 1: General information

1.1 Introduction

The Polycon system is a wireless extension of an aircraft’s ICS. The system consist of one
base station and one or more handheld radios. The base station is connected to the aircraft’s
ICS and the handheld radios are connected to a headset. The headset can be incorporated
in the helmet of the users. The base station works as a repeater station; both between the
wireless crew, as well as between wireless crew connected through Polycon and crew
connected to the wired ICS onboard the aircraft.

The system allows the users equipped with Polycon wireless radios to communicate with the
rest of the crew as if he/she was connected to the wired part of the ICS. Due to purpose built
technology and utilizing the UHF radio band the wireless users may leave the aircraft and still
retain robust and dependable communication over long distances, and to some extent even
when the radio is submerged.

Both the base station and the handheld units operate with Axnes Patented None Interrupted
Voice activated transmission (NIVOX) solution, securing optimal VOX control of the
communication. Noise cancelling electronics incorporated makes VOX operation achievable
even inside or in close vicinity of the aircraft, on ground or in hover mode.

The MP20 series hand held radio is a portable waterproof radio for wireless communication
with the aircraft crew while operating inside or outside of the aircraft. The MP20 series hand
held radio can be connected to the winch man’s helmet/headset, or used as a hand held
Walkie-Talkie. The system provides two-way voice communications between the helicopter
crew and SAR winch man, whilst the winch man is either outside the aircraft during winching
operations or remote from the aircraft.

The system has been designed for minimum weight, size and power consumption, combined
with the ruggedness and functionality required to meet the demanding environmental
conditions typical for its operational use.

The MP20 series hand held radio is designed for functional integrity, providing ease of
operation, while at the same time safeguarding against interruptions caused by unintentional
operation.

The MP20 series hand held radio will interface with the winch man’s helmet/headset to
permit hands free communication.

The MP20 Series hand held radio offers casualty communication - allowing the winchman to
communicate through the MP20 internal microphone with the injured person without
removing the helmet/headset.

The system can be programmed with up to 16 channels in the ranges of 408,600 – 409,600
MHz (Rx of base station) and 418,600 – 419,600 MHz (Tx of base station), and in the
maritime VHF band for dual band radios. To accommodate for individual customer
requirements, or national radio licensing authority regulations, other frequencies outside this
range may be supplied as a customization with some limitations inside the 406 to 470 MHz
frequency band.

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This manual describes the installation and operation of the Polycon MP20 series hand held
radio. The Polycon MP20 series hand held radio will hereafter be referred to as MP20

1.2 Mechanical description

The outline of the mechanics is found in Figure 1-1.
The chassis is made out of painted saltwater resistant milled aluminium, and consist of two

main parts, a main body and a back plate.
Helmet/headset connection is located at the top of the MP20 together with a small display,

antenna and a pressure equalizer.
The channel selection buttons, a large Push to Talk (hereafter named PTT) button used

when connected to the helmet/headset, as well as integral microphone and loudspeaker is
located at the front of the MP20. Volume up/down and walkie talkie PTT is located at the left
hand side of the MP20.

Charging connector is located in the bottom of the radio.
The mechanics are designed to withstand the robust operating environment typical

demanded by winch/SAR operation.
The MP20s are designed with all control buttons flush mounted to the cabinet, protecting

them from both damage and accidental operation, whilst the form and position of the front
PTT key enables it to be operated with a wide variety of grip positions.

The MP20 consists of the following main circuit board modules and electronic components:

 Radio module
 Interface processing module
 Display module
 Side key module
 Charger connector module
 Battery

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Figure 1-1: MP20 outline

1.3 Connectors and Control Functions

Electrical connections to the MP20 are located on the top and bottom of the MP20. The
electrical connections consist of:

 Waterproof 10 pin Fisher connector for helmet/headset connection.
 Plate connector for charging

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The control functions are as follows:

 Display for channel indication, and configuration menu (located on top).
 Channel selector (located on front).
 Volume and power on/off (located on the left hand side).
 Large PTT button for helmet/headset operation (located on front)
 PTT button for walkie talkie operation (located on left-hand side)
 Loudspeaker for walkie talkie operation (located on front)
 Microphone for walkie talkie and casualty communication (located on front)

1.4 Electrical and functional description

The MP20 is the handheld unit in a wireless extended ICS system and interacts with the
Polycon 004RLI base station. A MP20 is typically connected to a winchman helmet/headset,
and implements the following features:

 Wireless extension of aircraft’s intercom system with significant range and

robustness.

 Range up to 10 nm line of sight over water, and good ability to penetrate into

structures.

 Operating in half-duplex mode and utilizes the UHF band.
 Support for selected Maritime VHF channels (MP20 dual band only)
 Programmable with up to 16 channels.
 NIVOX – Polycon patented VOX operation. Conventional Voice Operated

transmission (VOX) operates by opening transmission when input has reached a
certain level over a given period of time. This will normally cause ‘clipping’ of the first
word in the transmission, and may cause difficulty in differentiating between words

such as ‘No’ and ‘Go’. Polycon implements a Non Interrupted Voice Activated

transmission (NIVOX). Polycon NIVOX will ensure non-clipped transmission of all
input, and full words are transmitted, without the drawback of traditional VOX.

 Adaptive NIVOX trigger level. The NIVOX will monitor the ambient noise, and through

this process avoid triggering transmission based on high background noise levels. A
given voice overlay to the noise is needed to trigger transmission. This functionality
secures that the intercom is not flooded with the background noise.

 Easily available PTT button (designed for elbow operation)
 Protected channel select buttons.
 Protected Volume/power on/off buttons
 “Low profile” antenna
 Built-in loudspeaker and microphone for MP20 operation (Walkie-Talkie).
 Intercom from integral microphone to helmet/headset earphones for casualty

communication.

 Side mounted PTT key for MP20 operation (Walkie-Talkie)
 Side-Tone function.
 Rugged and salt water resistant aluminium enclosure.
 Waterproof to 1 meter

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1.5 Identification of article

The MP20s are labelled with a part number. A standard unit operates in the UHF band at
419/409 MHz Rx/Tx, and will be labelled MP20-00U or MP20-01U for single band and MP20­02DB-414 for the dual band. Other frequency combinations may be configured at customer
request and will be labelled MP20-00U-xxx or MP20-01U-xxx for single band and MP20­02DB-xxx for dual band, where xxx denotes the centre frequency of the antenna.

Note: Some early units deviate from the product numbering scheme and a combination of the
product number and the antenna label must be used to identify the customer configuration.

Note: Some customer configured units deviate from the product numbering scheme and use
MP20-00U-xxx, were xxx represent an alphanumeric customer id. For those units the
combination of Tx and Rx is found in the datasheet supplied with the unit.

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1.6 Technical data

1.6.1 Operation

Radio:

Half duplex, dual frequency Rx/Tx

Frequency:

Tx:409±0.5 MHz Rx:419±0.5 MHz

VOX operation:

Axnes’ patented NIVOX, ensures no loss and operation in
high noise environment

Number of wireless users:

Unlimited

Number of Radio channels:

Up to 16

Encryption:

None

Operating temperature:

-25°C to 55°C

Storage temperature:

-40°C to 85°C

Water resistance

IEC EN60529 Edition 2.1.2001:02 IPX7 Category 1 (1
metre)

Pressure to activate front PTT:

0.5 to 1.0 Kg (Withstands a temperature drop of at least
20°C).

1.6.2 Power supply

Supply voltage:

Battery operated at 4.8V (1460mAH NiMh)

Operating time:

10 hours standby

8 hours receive

1.3 hours transmit (400mW)

Charge time:

2-3 hours

Charger:

CHG1236 M/S

1.6.3 Headset interface

Microphone sensitivity:

MP20-02DB: 0.1 – 60mVrms (0.3 – 180mVpp)

MP20-00U: 0.1 – 5mVrms (0.25 – 15mVpp)
MP20-00U: S/N 020765, 020781 and after as MP20­02DB.

Microphone input impedance:

136 Ω impedance balanced

Microphone bias:

4.1V through 2,7K series impedance (Mic+)

Power supply in connector:

MP20-02DB: 4.8V up to 40 mA

MP20-00U: Battery power through 1,5KΩ series resistor
MP20-00U: S/N 020765, 020781 and after as MP20­02DB.

Headset output (mV rms):

Vol:

0 3 6 9

Open:

170

610

1030

1780

9 Ω:

105

385

650

1150

150 Ω:

160

590

995

1720

600 Ω:

167

605

1020

1770

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1.6.4 Helmet/headset Connectors

Connector on MP20:

Fisher DBEU1031A010-130

Compatible cable mount :

Fisher SE1031A010-130

1.6.5 Radio characteristics

UHF Tx frequency:

409 MHz (other frequencies as customer configurations)

UHF Rx frequency:

419 MHz (other frequencies as customer configurations)

UHF Duplex separation:

10 MHz

VHF Frequency band:

156-159 MHz (only MP20-02DB series)

Channels:

16

Channel separation:

25 KHz

Modulation:

FM

Frequency stability:

25 KHz +/- 5 ppm

Receiver sensitivity

<0.9 μV at 12 dB SINAD (single band)

Output power:

400 mW (other output power as customer configurations)

Deviation:

5 KHz

Antenna impedance

50 Ω

1.6.6 Dimensions

Physical dimensions:

112 x 65.5 x 35 mm

Weight:

395g

1.6.7 Material

Material:

Aluminium 5052 (Salt Water Resistant)

Paint:

Layer1: 2 comp. Wash primer CR, Sikkens/Akzo Nobel

Layer2: 2 comp. Auto Nova – None Sanding.
Sikkens/Akzo Nobel

Layer3: 2 comp. Cooler Polyurethane Sikkens BT,
Sikkens/Akzo Nobel

Colour

BT429DS(yellow)/BT499G3(grey)

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1.7 Type approvals and records

1.7.1 Type approvals

The Polycon MP20 series MP20s have been tested against general radio terminal
specifications, as defined in:

 ETSI EN301 843-2 V1.1.1 Electro Magnetic Compatibility (EMC) standard for marine

radio equipment and services; Part 2: Specific conditions for radiotelephone
transmitters and receivers

 ETSI EN 300 720-2 V1.2.1 Ultra-High Frequency (UHF) on-board vessels

communications systems and equipment; Part 2: Harmonized EN under article 3.2 of
the R&TTE Directive

 ETSI EN 300 178-1 V1.3.1 Portable Very High Frequency (VHF) radiotelephone

equipment for the maritime mobile service operating in the VHF bands (for non­GMDSS applications only)

 IEC EN 60529 Edition 2.1 2001-02 Degrees of Protection Provided by Enclosures (IP

code): IPX7 Category 1

 IEC EN 60950-1:2006 Information technology equipment – Safety

1.7.2 Type Records

The Design Authority will submit a Declaration of Design Performance (DDP).
The DDP will reference the following:

 Design Specification.
 Equipment Specification Number and Issue Number.
 General Assembly Drawings and Aircraft Equipment installation information.
 Master Record Index.
 List of Type Test Reports.

1.8 Accessories

Article

Part no:

Battery charger CHG1236M/S

AX-CHG-0010

Battery charger CHG1236M/S, power supply w/AUS plug

AX-CHG-0020

Battery charger CHG1236M/S, power supply w/EU plug

AX-CHG-0030

Battery charger CHG1236M/S, power supply w/UK plug

AX-CHG-0040

Battery charger CHG1236M/S, power supply w/US plug

AX-CHG-0050

Table 1-1: Accessories

Axnes Aviation can supply a number of accessories related to MP20 series handheld radios,
ranging from adaptor cables to helmets. For details please visit:

http:\\www.axnes.com\products

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Section 2: Installation

2.1 General

The MP20 series handheld radios do not require any installation, but depending on aircraft,
operational environment and microphone configuration, some radio parameters may need
adjustment to ensure optimal performance.

Care should be taken when selecting helmet/headset microphone to ensure Polycon MP 20
compatibility.

2.2 Inspection before installation

Before taking MP20 radios into use, carry out visual inspection for any transport damage,
paying particular attention to the following:

- Dirt, dents, scratches, corrosion, broken attaching parts on the housing and housing parts.

- Dirt and scratches on the identification plate, and marking.

- Dirt, bent or broken pins, cracked connector inserts.

- Missing screws or pressure relief pin.

2.3 Recommended maintenance

The MP20 should be serviced by an Axnes Aviation certified service centre according to the
recommended maintenance schedule. Recommended according to service letter published
at Axnes resource website:

http://www.axnes.com/resource-center/service-letters/
Axnes Aviation certified service centres are found at:
http:\\www.axnes.com\support
or contact Axnes Aviation A/S at:
Phone: [phone]
FAX: [phone]
E-mail: [e-mail]
The MP20 hand held radio should always be thoroughly cleaned and stored in a dry and

ventilated location. After use, immersion in salt water or exposure to salt laden or dusty
atmosphere, the hand held radio must be washed in clean running water and dried off with a
soft cloth.

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Plug connections should be blown dry with clean dry air (low pressure) and protected with
acid-free Silicone grease Type “NOVA G624” or similar after drying. Always recharge the
hand held radio after use.

Although the connector arrangement is a waterproof type, under certain circumstances it is
possible for water to seep between the plug and the socket, causing undesirable
interference. This may be avoided by liberal application of silicone grease.

Do not carry the radio by the helmet/headset connecting lead.
Do not try to disconnect the helmet/headset connector by snatching or pulling the lead.
The radio should be secured to the vest or pocket by means of a lanyard connected to the

dedicated lanyard ring on the radio back plate.
If the MP20 is not operating normally, check indicator lights and channel settings. Check also

connectors for proper attachment.
A malfunction may also be corrected by switching the system OFF for a few seconds and

then ON again.
If you have trouble making the MP20 operate and before declaring the unit unserviceable, it

is recommended to go through the reset procedure found in the document “AX-SVS-PRC­0002 Reset Procedure”. This procedure will restore the unit to factory defaults and possibly
clear any setting made accidentally, causing the unit not to operate properly. The reset
document can be downloaded from:

http:\\www.axnes.com\support
All repairs are to be undertaken by Axnes Aviation A/S certified repair centres only.

2.4 Mechanical installation

No mechanical installation of MP 20 is required.
The radio, including the batteries, is capable of immediate use even after storage in its

original packing for up to 2 years at temperatures within the range -40°C to +50°C. However
the equipment should first allow being acclimatised to within the operational temperature
range (-25°C to +55°C).

2.5 Installation wiring consideration

No aircraft wiring is needed for the installation of the MP20 series radio.

2.6 Dimensions Polycon MP20 series hand held radio

Please Refer to Figure 1-1: MP20 outline.

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2.7 Location of connectors and pin assignment

MP20 series has two connectors, one for helmet/headset and one for charging.
Charging connector is located in the bottom of the unit and is of the plate type. The

helmet/headset connector is located at the top of the unit. Both connections are water proof.

2.7.1 Helmet/headset connection pin assignment

The helmet/headset connector pin-out is listed in Table 2-1: 10 Pin waterproof
helmet/headset connector. For electrical specification of the pins, please refer to 1.6.3
Headset interface.

Pin

Function

1

Mic+

2

Mic-

3

Speaker +

4

Speaker -

5

GND

6

Manufacturing use

7

Manufacturing use

8

Manufacturing use/PTT1

9

DC out

10

Manufacturing use

Table 2-1: 10 Pin waterproof helmet/headset connector

The connector on the Polycon MP20 is:
Water proof Fisher 10 Pin, panel mount, part no.: AX-CON-0010 (alt. part no.:

DBEU1031A010-130).
The compatible connector for helmet/headset wiring:
Water proof Fisher 10 Pin plug, cable mount, part no.: AX-CON-0010 (alt. part no.:

SE1031A010-130).

2.8 Microphone compatibility

Care should be taken when selecting a microphone to be used with the MP20s. The MP20
input levels are specified in technical data section 1.6.3. It should be noted the supply
voltage to bias the microphone is limited.

1

Valid for units with software version 3.0 or higher. Units with software version 3.0 or higher will show

the software version as two digits in the display at startup.

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The MP20 will detect a headset/helmet connection through a change of the impedance over
the microphone terminals. The DC resistance trough the microphone line is required to be
less than 10 kΩ.

Note: Some types of electret microphones change their DC resistance when subjected to
very high sound input. This can cause the impedance to go over the threshold of the
headset/helmet operation mode (10K).

2.9 Post installation calibration

When the MP20 is taken into use, normally no adjustments are needed, and factory values
can be used. In some cases adjustment might be needed as listed below:

White noise in headset. Adjust the squelch – Pre software version 3.02:To adapt the
squelch on the Polycon MP20, press the large front PTT button and simultaneous operate
‘volume up’ or ‘volume down’. Squelch setting is displayed in the display.

Software version 3.02and higher: Press the Volume up and Channel down once
simultaneously to enter menu mode. To browse through the menu press channel up/down.
Select option ‘’ SL’’ – the display will change to display the value of the set squelch level. The
squelch level can be adjusted by using the Vol up / down buttons to set as required.

When optimal level is found press the side PTT button to save and exit.
It is recommended to note down the optimal level for future reference in the calibration

parameter sheet found in Appendix A.
Factory squelch level: Individual values, normally between 18-21.

NIVOX transmission from Polycon MP20 series hand held radio not triggered or
triggered by noise. Adjust Analogue trigger level – Analogue trigger level is the level of the

voice on top of the background noise needed to trigger VOX transmission. Lowering the
analogue trigger level will make the VOX operation of the radio more sensitive to rapid
changes in the background noise, and will require a lower voice overlay level to trigger
transmission. Increasing the setting will make the radio VOX operation more robust to rapid
changes in the background noise, but will require higher levels of voice overlay to trigger
transmission.

Note: The when the noise environment or analogue level change the radio needs a few
seconds to adapt the new noise level. It is recommended to adjust the analogue level in a
noise environment similar to the operational environment.

To adjust the analogue trigger level, press the Volume up and Channel down once
simultaneously to enter menu mode.To browse through the menu press channel up/down.

Select option ‘’AL’’ – the display will change to display the value of the set analogue level.
The analogues level can be adjusted by using the Vol up / down buttons to set as required.

2

Units with software version 3.0 or higher will show the software version as two digits in the display at

startup.

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When optimal level is found press the side PTT button to save and exit.
The standard factory setting is 78, but this does depend on the type and output of the

microphone used and the noise levels in the operating environment.
Experience has showed that a value between 60 and 80 will work in most cases. When the

optimal level has been found, it should be used as the new default setting. It is
recommended to note down the optimal level for future reference in the calibration parameter
sheet found in Appendix A.

Factory setting AL: 78.

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Section 3: Operation

3.1 MP20 series charging

Please make sure to fully charge the MP20 before using the unit the first time. The MP20 is
equipped with NiMh batteries and a charge cycle will normally take approximately 3 hours
from when the battery is empty.

The MP20 will indicate a low battery condition at approximately 10% remaining battery
capacity. This will be indicated with a low battery warning tone in the helmet/headset or
loudspeaker.

The MP20 must be charged using the Polycon CHG 1236 M/S charging unit. The charging
cradle is designed to fit the radio and to keep the radio stable and secure while charging. A
green indicator in the charger will illuminate during charging, and will start flashing when the
charging cycle is complete, and the radio is fully charged.

MAKE SURE THE MP20 IS SWITCHED OFF DURING CHARGING.
If fully discharged, the charging might needed to be restarted after the unit has been in the

charger for a few minutes. Please do so by lifting the unit out of the charger and putting it
back in again to ensure a correct charge cycle.

3.2 Power Up/Down Sequence

Power ON/OFF and Volume is controlled by two buttons located on the side of the cabinet.
The upper button controls the ON- and Volume-UP functions, while the lower button controls
the OFF and Volume-DOWN functions.

To turn the radio on, press the “On/Volume UP” button. The radio will be switched on, and a
long start-up indication tone will be heard. The unit will then be in stand by mode, set to a
pre-defined Power-Up volume setting. Units with software version 3.0 and higher will do a
display test showing ‘8.8.’ in the display followed by the software version displayed as a two
digit code.

To turn the unit OFF, press the Off/Volume Down button until the volume is at 0 and continue
holding it until a long “beep” tone is heard. The display will be switched off and indicate that
the unit is turned off.

The Volume can be controlled by rapidly pushing the volume buttons step-by-step, or by
holding the button. When adjusting the volume it will be indicated on the unit display as well
as by a corresponding beep tone volume.

Axnes Aviation AS

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Page 3-2

When the unit is switched on it will automatically load the following settings:

 Transmit power level : ‘Normal’3
 Automatic Gain Control: As set at power down4
 Squelch: As set at power down
 Volume: Set to factory programmed power up volume setting
 NIVOX/PTT mode: As programmed by user. Factory default ‘NIVOX’4
 Channel: As set at power down

3.3 Change channel

Up to 16 channels may be pre-programmed and selected stepwise by pressing the channel
up and channel down button on the front of the MP20. On the first operation of the channel
buttons, the display will change mode to show the active channel, and repeated pushes will
let you browse through the pre-programmed channels.

Note: For dual band version of the MP20 it is recommended to configure the UHF channels
with display text 90-99 to be able to differ the UHF channels from the maritime VHF
channels. The display text is defined by customer when ordering the units, but limited to 2
decimal numbers.

Units with software version 3.04 or higher will indicate VHF channel by an illuminated dot in
the display.

3.4 Walkie-Talkie mode

When no headset is connected to the MP20, the unit can be operated in Walkie-Talkie mode.
In this mode the internal microphone and loudspeaker is utilised and the transmission is
controlled by the side PTT button.

3.5 Helmet/Headset connection

Connect the helmet/headset to the 10 pin connector on the MP20 top panel. Align the two
red marks on the plug and receptacle and push until the plug locks.

The plug cannot be removed by pulling the wire, but must be unlocked by pulling the outer
case of the plug, releasing the locking mechanism.

When a helmet/headset is connected, to the MP20 unit, the Walkie-Talkie function is
disabled (MP20 internal microphone and loudspeaker), and the operational mode is set to
NIVOX or PTT according to the selected default mode4.

3

EP transmit power level is only valid for MP20-00U series and should not be altered for MP20-02DB

series.

4

Possibility of changing Automatic gain control, default NIVOX/PTT mode, and display orientation is
not available for software version 3.0 and higher. Units with software version 3.0 or higher will show
the software version as two digits in the display at startup.

Axnes Aviation AS

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Date

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Issue E

2015-03-05

Page 3-3

3.6 NIVOX/Push to Talk (PTT) Operation

When a helmet/headset is connected to the MP20, the NIVOX (Non Interrupted Voice
Operated X-mission) or PTT function is automatically activated according to the default
setting5.

In Axnes’ patented NIVOX mode, transmission will be voice activated, and transmission will
stay open for a pre-programmed hang time after voice audio input has ended. The MP20 will
monitor the ambient noise levels and use this to differentiate voice input from ambient noise.
This feature will allow the Polycon MP20 to adapt and operate in NIVOX mode even in high
noise environments far better than traditional VOX systems.

In PTT mode the transmission is controlled by pressing the large front PTT. In both PTT
mode and NIVOX mode, transmission is indicated in the display as ‘oo’.

When the MP20 operates in NIVOX mode, pressing the front PTT button will change the MP
20 operational mode from NIVOX to PTT mode. In the PTT mode the large front PTT will
have to be pressed in order to start audio transmission.

To move back to NIVOX mode, the side PTT can be pressed twice. The first press will set
the MP20 to Person to Person mode (indicated in the display with ‘PP’), and the second will
set the MP20 back to NIVOX (indicated in the display with ‘--’ in standby or ‘oo’ if
transmission is triggered).

When default mode is set to PTT, NIVOX can be activated by press and hold side PTT
button and Front PTT button simultaneously for about 5 seconds, until a short beep is being
heard.

Disconnecting and re-connecting the headset will set the MP20 back to default PTT/NIVOX
setting5.

3.7 Person to Person / Casualty Communication mode

Person to Person- or Casualty Communication mode enables the Polycon user wearing a
noise attenuating helmet/headset to hear nearby conversation through the MP20 internal
microphone in the helmet/headset without removing the same.

Setting the MP20 in person to person mode, will disable the NIVOX mode and open the
microphone in the MP20 so that surrounding audio is picked up and transferred to the local
headset. The communication received from the base station in the aircraft, is still audible in
the headset and mixed with the person to person communication.

Any audio picked up in the internal MP20 microphone with the person to person mode
activated is NOT transferred back to the helicopter.

5

Possibility of changing Automatic gain control, default NIVOX/PTT mode, and display orientation is
not available for software version 3.0 and higher. Units with software version 3.0 or higher will show
the software version as two digits in the display at startup.

Axnes Aviation AS

Document number

Revision

Date

AX-PSB-UMAN-0027

Issue E

2015-03-05

Page 3-4

To enable the person to person communication, make sure helmet/headset is connected,
and press the side PTT button once. ‘PP’ will be indicated in the display.

In person to person mode, the transmission from MP20 is disabled, while reception will
continue on the selected channel.

If the front PTT is pressed while in person to person mode, the MP20 is changed to PTT
mode and transmission is activated.

To change back to person to person mode, the side PTT must be pressed once, and ‘PP’ will
be displayed indicating that the person to person mode is active.

To change from PP mode to NIVOX mode, press the side PTT once, and ‘- -‘ will be
displayed indicating the unit is in standby mode.

3.8 Display orientation6

The display orientation may be rotated by pushing the two channel selector buttons
simultaneously. This feature may be used to orient the display according to the operational
needs and enable the user to get the correct orientation independent from how the MP 20 is
carried.

3.9 Output Power Settings

The Polycon MP20 has a standard power output at about 300mW. When the battery is
discharged the output power may be reduced (single band only), and to manually
compensate for this there is an option to enable an “emergency” full power output setting to
ensure maximum range at the end of battery charge cycle.

Emergency power is entered in menu mode by pressing channel up and volume down. Then
press channel up or down until ‘nP’ or ‘EP’ is displayed.

Normal power is indicated as ‘nP’ and emergency power is indicated as ‘EP’.
To change between normal power and emergency power, press volume up or down.
To store the selection and leave menu mode, press the side PTT button.
Note: Under normal operation and charge status, radios should be operated in ‘nP’.
Note: The EP setting should never be set in MP20-02DB series radios. MP20-02DB series

radios has specified output power until end of battery capacity. The EP setting has been
disabled for MP20-02DB series radios with software version 3.06 and higher.

6

Possibility of changing Automatic gain control, default NIVOX/PTT mode, and display orientation is
not available for software version 3.0 and higher. Units with software version 3.0 or higher will show
the software version as two digits in the display at startup.

Axnes Aviation AS

Document number

Revision

Date

AX-PSB-UMAN-0027

Issue E

2015-03-05

Page 3-5

3.10 Pressure Equalizing Actuator

Significant changes in altitude and/or temperature may make the PTT button difficult to press
or may unintentionally activate the transmitter due to over or under pressure within the
MP20. To overcome this the ”Pressure Equalising Actuator” located on the top of the
transmitter should be manually operated by pushing the centre pin to one side with a finger.
The pressure inside and outside of the MP20 will be equalised, see illustration below.

Push sideways to activate the Equalizing.

3.11 Default Settings

The MP20 is configured with the following default settings:

 Automatic Gain Control: Factory default ‘On’7
 Squelch: Factory default 19
 Power on volume: Factory default 4 (not changeable in field)
 NIVOX/PTT mode: Factory default ‘NIVOX’
 Analogue level: Factory default 78

Changing the defaults is described in the following.

3.11.1 Select NIVOX or PTT default7.

When a helmet/headset is connected to the MP20, the mode of operation will be activated
according to a default setting.

To select PTT as default configuration when a helmet/headset is connected: Press and hold
the front PTT button simultaneously with power up. The MP20 is now set to default PTT
mode.

To select NIVOX as default configuration when a helmet/headset is connected: Press and
hold the side PTT button simultaneously with power up. The MP20 is now set to NIVOX
mode.

7

Possibility of changing Automatic gain control, default NIVOX/PTT mode, and display orientation is
not available for software version 3.0 and higher. Units with software version 3.0 or higher will show
the software version as two digits in the display at startup.

Axnes Aviation AS

Document number

Revision

Date

AX-PSB-UMAN-0027

Issue E

2015-03-05

Page 3-6

3.11.2 Squelch

Per software version 3.08:The squelch can be adjusted by pushing the front PTT button and
simultaneously operate the “Volume-UP” or “Volume-DOWN” buttons.

Software version 3.08and higher: Press the Volume up and Channel down once
simultaneously to enter menu mode. To browse through the menu press channel up/down.
Select option ‘’ SL’’ – the display will change to display the value of the set squelch level. The
squelch level can be adjusted by using the Vol up / down buttons to set as required.

When optimal level is found press the side PTT button to save and exit.
Correct squelch setting is depending on the operation environment. Typically the squelch

setting is set between 20–27.

3.11.3 Automatic Gain Control (AGC)8

The MP20 features an Automatic Gain Control (AGC) on the microphone input, to secure
optimal performance in environments where the background noise varies. The AGC is
central for the MP20 performance in noisy environments and should always be activated.

It is possible to toggle the AGC setting by pressing the Volume up and Volume down once
simultaneously. The display will show either “On” or “OF”, indicating the AGC status. It is not
recommended to turn AGC off.

Note1: Please note that each time you actuate the buttons to check the AGC setting - you
toggle the setting on or off.

Note2: Experience shows that toggling AGC on/off may happen inadvertently. It is
therefore strongly recommended that the users of the equipment know how to check
the AGC status, to secure optimal performance of the equipment.

3.11.4 Analogue Trigger Level (NIVOX Threshold)

Analogue trigger level is the level of the voice overlaid on the background noise needed to
trigger VOX. Lowering the analogue trigger level will make the VOX operation of the radio
more sensitive to rapid changes in the background noise, and will require less voice overlay
to trigger transmission. Increasing the setting will make the radio VOX operation more robust
to rapid changes in the background noise, but will require higher levels of voice overlay to
trigger transmission.

To adjust the analogue trigger level, press the Volume up and Channel down once
simultaneously to enter menu mode. The display should show ‘’AL’’.

8

Possibility of changing Automatic gain control, default NIVOX/PTT mode, and display orientation is
not available for software version 3.0 and higher. Units with software version 3.0 or higher will show
the software version as two digits in the display at startup.

Axnes Aviation AS

Document number

Revision

Date

AX-PSB-UMAN-0027

Issue E

2015-03-05

Page 3-7

Note: To browse through the menu press channel up/down. The menu has two entries, one
for adjusting the power setting, displayed as ‘nP’ or ‘EP’, and one for adjusting the analogue

level displayed as ‘AL’.
Select option ‘’ AL’’ – the display will change to display the value of the set analogue level.

The analogue level can be adjusted by using the Vol up / down buttons to set as required.
When optimal level is found press the side PTT button to save and exit.
The standard factory setting is 78, but the optimal setting will depend on the type and output

of the microphone used and the noise levels in the operating environment. Typically a setting
between 60 and 80 will be used.

Axnes Aviation AS

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Intentionally left blank

Axnes Aviation AS

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Issue E

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Page a

Appendix A Calibration parameters

The MP20 is calibrated and configured with default parameters at the factory. Additional
channels and custom frequencies are available on request, and will be configured as part of
the custom production process.

Some parameters are possible to change in the field and are described further in the table
below.

Changes to parameters should only be done by qualified personnel only

Aircraft: _
MP20 serial number: _

Parameter

Description

Factory
setting

Customer
calibration

Squelch

Squelch setting for receiver [0-99]

18-21

AGC
(Automatic
Gain Control)

Automatic gain control on/off. AGC

‘on’ ensures optimal performance of

MP20 in noisy environments [On/Off]

ON

Analogue
trigger level –
NIVOX

Voice overlay level needed to trigger
NIVOX.

78