Becker RT6512 User manual

Becker Avionics GmbH •Baden-Airpark B108 •77836 Rheinmünster •Germany
+49 (0) 7229 / 305-0 •Fax [phone] / 305-217
http://www.becker-avionics.com •E-mail: [e-mail]
Remote-Controlled
VHF-AM Transceiver
RT6512
Installation and Operation
Manual DV17501.03
Issue 07 November 2019
Article-No. 0645.702-071

Installation and Operation
Becker Avionics
2 RT6512 DV17501.03 Issue 07 November 2019
Approved Production and Maintenance Organization
Certificates see: http://www.becker-avionics.com/certification/ →Certificates
Contact data for:
Europe, Asia,
Oceania and
Africa
Becker Avionics GmbH
Baden-Airpark B108
77836 Rheinmünster (Germany)
Tel.: + 49 (0) 7229 / 305-0
Fax: + 49 (0) 7229 / 305-217
Internet: www.becker-avionics.com
Email: [e-mail]
Customer Service:
Email: [e-mail]
Contact data for:
America,
Australia, Japan
Becker Avionics Inc.
Email: [e-mail]
WARNING - USER RESPONSIBILITY
FAILURE OR IMPROPER SELECTION OR IMPROPER USE OF THE PRODUCTS DESCRIBED
HEREIN OR RELATED ITEMS CAN CAUSE DEATH, PERSONAL INJURY AND PROPERTY
DAMAGE.
This document and other information from Becker Avionics provide product or system options for
further investigation by users having technical knowledge.
The user is responsible for making the final selection of the system and components. The user has to
assure that all performance, endurance, maintenance, safety requirements of the application are met
and warnings be obeyed.
For this the user has to include all aspects of the application to be compliant with the applicable
industry standards and the requirements of the responsible aviation authority. The product
documentations from Becker Avionics have to be obeyed.
To the extent that Becker Avionics provide component or system options based upon data or
specifications provided by the user, the user is responsible for determining that such data and
specifications are suitable and sufficient for all applications and reasonably foreseeable uses of the
components or systems.
Term definition: User in the sense of user, installer, installation company.

Becker Avionics
Installation and Operation
DV17501.03 Issue 07 November 2019 RT6512 3
Preface
Dear Customer,
Thank you for purchasing a Becker Avionics product. We are pleased that you have chosen our
product and we are confident that it will meet your expectations.
For development of our products, the guidelines for highest quality and reliability have been borne in
mind, supplemented by selection of high-quality material, responsible production and testing in
accordance to the standards.
Our competent customer support department will respond on any technical question you may have.
Please do not hesitate to contact us at any time.
Remote-Controlled VHF-AM Transceiver*
RT6512 (Remote Transceiver)
without mounting tray
* design depends on variant.
* Some figures in this manual are for basic
understanding and can be different to the actual design.

Installation and Operation
Becker Avionics
4 RT6512 DV17501.03 Issue 07 November 2019
List of Effective Pages and Changes
Only technical relevant modifications are described in this table.
Document: DV17501.03 / issue 07 Article Number 0645.702-071
Cover Page 11/2019
Introduction 11/2019
Chapter 1 – 4 11/2019
Issue Page No.: Section /
Chapter Description
07 1-64 all Updated: Editorial adjustments.
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1.8
1.8.10 Updated: Technical data and certifications.
-- 1.9.2 Updated: Accessories.
2 Added: Information about installation.
-- 2.7 Updated: Aircraft Wirings.
--
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© by Becker Avionics GmbH / all rights reserved

Becker Avionics
Installation and Operation
DV17501.03 Issue 07 November 2019 RT6512 5
Table of Contents
1General Description .................................................................................................................... 11
1.1 Introduction.................................................................................................................................. 12
1.2 Purpose of Equipment................................................................................................................. 13
1.3 Variants Overview ....................................................................................................................... 13
1.4 Associated Devices..................................................................................................................... 13
1.5 Scope of Functionality................................................................................................................. 14
Receive Mode ................................................................................................................... 14
Transmit Mode .................................................................................................................. 14
Emergency Mode.............................................................................................................. 14
Audio Inputs and Outputs ................................................................................................. 15
1.5.4.1 Microphone Input ......................................................................................................... 15
1.5.4.2 Audio Input LINE IN ..................................................................................................... 15
1.5.4.3 Audio Output LINE OUT .............................................................................................. 16
Control Inputs.................................................................................................................... 16
1.5.5.1 /ON (Unit Power ON/OFF Control) .............................................................................. 16
1.5.5.2 /PTT (Push-To-Talk) .................................................................................................... 16
1.5.5.3 /COM2 (Com Addressing Line) ................................................................................... 16
1.5.5.4 /SEL422 (Serial Interface Selection Line).................................................................... 16
1.5.5.5 /RX_ATT (External RX Attenuation Control) ............................................................... 17
1.5.5.6 /SERV_EN (Enabling the Setup Modes) ..................................................................... 17
1.5.5.7 /TX-ENABLE (Enabling the TX)................................................................................... 17
1.5.5.8 /EMERG (Enabling the Emergency Mode).................................................................. 17
Status and Control Outputs .............................................................................................. 18
1.5.6.1 /FAILURE..................................................................................................................... 18
1.5.6.2 RX_AGC (AGC Voltage of the RX-RF-AGC) .............................................................. 18
1.5.6.3 /SQL_EVAL ................................................................................................................. 18
Digital Interfaces to the Control Unit ................................................................................. 19
1.5.7.1 Interface ARINC 429.................................................................................................... 19
1.5.7.2 Interface RS422........................................................................................................... 19
1.6 Safety-Conscious Utilization ....................................................................................................... 20
1.7 Restriction for Use....................................................................................................................... 20
1.8 Technical Data ............................................................................................................................ 21
General Characteristics .................................................................................................... 21
Typical Power Consumption ............................................................................................. 21
Receiver Data ................................................................................................................... 22
Transmitter Data ............................................................................................................... 23
Dimensions & Weight........................................................................................................ 23
Software ............................................................................................................................ 24
Hardware .......................................................................................................................... 24
Continued Airworthiness ................................................................................................... 24
Environmental Conditions ................................................................................................. 25
Certifications ..................................................................................................................... 26
1.8.10.1 RT6512 meets the Requirements of:........................................................................... 26
1.8.10.2 Guidelines followed for Design and Development....................................................... 26
1.8.10.3 FCC Approval .............................................................................................................. 27
1.9 Order Code.................................................................................................................................. 28
RT6512 ............................................................................................................................. 28
Accessories....................................................................................................................... 28
2Installation.................................................................................................................................... 29
2.1 Packaging, Transport, Storage ................................................................................................... 29
2.2 Device Assignment ..................................................................................................................... 30
Scope of Delivery.............................................................................................................. 30
State of Delivery................................................................................................................ 30
Additional Required Equipment (optional) ........................................................................ 30
Type Plate ......................................................................................................................... 31
Software/Firmware Status – Functionality ........................................................................ 31
Meaning of Status LEDs ................................................................................................... 31
2.3 Installation Requirements............................................................................................................ 32
Mounting Distance ............................................................................................................ 33
Mounting Tray MT6512..................................................................................................... 33
Grounding ......................................................................................................................... 33

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6 RT6512 DV17501.03 Issue 07 November 2019
Antenna Cables................................................................................................................. 34
2.3.4.1 Attenuation: Cable length versus coax cable type....................................................... 34
Antenna Installation........................................................................................................... 35
2.3.5.1 Required Antenna Type ............................................................................................... 35
2.3.5.2 Antenna Mounting Location ......................................................................................... 35
2.3.5.3 Recommendation for Installation of two RT6512 in one Aircraft ................................. 36
2.3.5.4 Radio Setting and Wiring for dual installation .............................................................. 36
2.4 Dimensions.................................................................................................................................. 37
RT6512.............................................................................................................................. 37
RT6512 with Mounting Tray MT6512................................................................................ 38
2.5 Connector Pin Assignments ........................................................................................................ 39
Connector P1 (RT6512) .................................................................................................... 39
Connector J2 (RT6512)..................................................................................................... 40
2.6 Equipment Configuration Samples.............................................................................................. 41
RT6512 with RCU6512 ..................................................................................................... 41
RT6512 with RMU5000..................................................................................................... 41
RT6512 with ARINC 429 Controller .................................................................................. 41
2.7 Aircraft Wiring .............................................................................................................................. 42
RT6512-(XX0) with RCU6512 as Primary Controller........................................................ 43
RT6512-(XX0) with ARINC 429 Controller........................................................................ 44
RT6512-(XX1) with ARINC 429 Controller........................................................................ 45
RT6512-(XX0) with Controller G7610 ............................................................................... 46
2.8 Post Installation Tests ................................................................................................................. 47
Mechanical Installation and Wiring Check ........................................................................ 47
Power Supply .................................................................................................................... 47
Receiver / Transmitter Operation ...................................................................................... 47
Antenna Check.................................................................................................................. 47
Interference Check............................................................................................................ 47
Flight Test Check .............................................................................................................. 49
3Operation ...................................................................................................................................... 51
3.1 General ........................................................................................................................................ 51
3.2 Device Description....................................................................................................................... 51
Device Assignment ........................................................................................................... 51
3.3 Operation with RCU6512 ............................................................................................................ 52
3.4 Operation with RMU5000 ............................................................................................................ 52
3.5 Operation with OEM Controller ................................................................................................... 52
3.6 Start-Up ....................................................................................................................................... 53
Built In Tests (BIT) ............................................................................................................ 53
3.6.1.1 Initiated Built In Test (IBIT) .......................................................................................... 55
3.6.1.2 Power On Built In Test (PBIT)...................................................................................... 55
3.6.1.3 Continuous Built In Test (CBIT) ................................................................................... 55
Device Status - Error Indication ........................................................................................ 56
3.6.2.1 Audible Error Announcement....................................................................................... 56
3.6.2.2 Status & Error Indication .............................................................................................. 56
3.6.2.3 No Error........................................................................................................................ 56
3.6.2.4 Test in Progress ........................................................................................................... 56
3.6.2.5 Internal Failure Indication............................................................................................. 57
3.6.2.6 External Failure Indication ........................................................................................... 57
3.6.2.7 Failure Indication when an "Internal" or "External" Failure is found ............................ 57
3.6.2.8 Error History Flags in the Service Set up..................................................................... 57
3.7 RS422 Protocol supported by RT6512 ....................................................................................... 58
3.8 ARINC 429 Protocol supported by RT6512 ................................................................................ 58
3.9 Read Out and Reset Error/Failure Flags..................................................................................... 58
3.10 Warning and Failure Indications.................................................................................................. 58
3.11 Contact Data................................................................................................................................ 60
4Index.............................................................................................................................................. 64

Becker Avionics
Installation and Operation
DV17501.03 Issue 07 November 2019 RT6512 7
List of Figures
Some figures in this manual are for basic understanding and can be different to the actual design.
Figure 1: Standard Microphone Input Schematic................................................................................................... 15
Figure 2: LINE_IN Schematic................................................................................................................................. 15
Figure 3: LINE_OUT .............................................................................................................................................. 16
Figure 4: /FAILURE Output Schematic .................................................................................................................. 18
Figure 5: Type Plate (Example) ............................................................................................................................. 31
Figure 6: RT6512 with MT6512 - mounting area.................................................................................................... 33
Figure 7: RT6512 Dimensions (without and with Main Connector applied)............................................................ 37
Figure 8: RT6512 with Mounting Tray MT6512...................................................................................................... 38
Figure 9: RT6512connectors ................................................................................................................................. 39
Figure 10: RT6512 with RCU6512......................................................................................................................... 41
Figure 11: RT6512 with RMU5000......................................................................................................................... 41
Figure 12: RT6512 with ARINC 429 Controller ...................................................................................................... 41
Figure 13: RT6512-(XX0) with RCU6512 as Primary Controller ............................................................................ 43
Figure 14: RT6512-(XX0) with ARINC 429 Controller............................................................................................ 44
Figure 15: RT6512-(XX1) with ARINC 429 Controller............................................................................................ 45
Figure 16: RT6512-(XX0) with Controller G7610 ................................................................................................... 46
Figure 17: Thermal Behavior for TX Function ........................................................................................................ 54
List of Abbreviations
List of Abbreviations
A3E
Amplitude modulation double-sideband with full carrier
AGC
Automatic Gain Control
AM
Amplitude Modulation
AOC
Air Operations Centre
ARINC
Aeronautical Radio Incorporated
ARINC 429
Data bus for commercial aircraft
ATS
Air Traffic Services
BIT
Built In Test
BNC
Bayonet Neill Concelman (connector)
CBIT
Continuous Built In Test
CU
Control Unit
DAL
Design Assurance Level
DC
Direct Current
EUROCAE
European Organization for Civil Aviation Equipment
EASA
European Aviation Safety Agency
FAA
Federal Aviation Administration
IBIT
Initiated Built In Test
LED
Light Emitting Diode
MISE
Ministero dello Sviluppo Economico (Ministry of Economic Development, Italy)
n/a
not applicable
OEM
Original Equipment Manufacturer
PBIT
Power On Built In Test
PSB
Power Supply Board
PTT
Push To Talk
RCU
Remote Control Unit
RMU
Radio Management Unit
RX
Receiver
SSW
Service Software
Std
Standard

Installation and Operation
Becker Avionics
8 RT6512 DV17501.03 Issue 07 November 2019
List of Abbreviations
TX
Transmitter
VDC
Volts Direct Current
VHF
Very High Frequency
VSWR
Voltage Standing Wave Ratio
TufLok®
Registered trademark. Thread locking patch
ELASTOSIL®
Registered trademark. Silicon products.
Units
Units
A
Ampere
mA
Milliampere
°C
Degree Celsius
dBm
Power ratio in Decibel referenced to 1 mW
dB
Decibel
ft
Foot
g
Gram
in
Inch
kHz
Kilohertz
MHz
Megahertz
mm
Millimeter
NM
Nautical Mile
kΩ
Resistance kilo Ohm
Ohm (Ω)
Resistance
ppm
Part per million
s
Second
V
Volt
mV
Millivolt
W
Watt
mW
Milliwatt

Becker Avionics
Installation and Operation
DV17501.03 Issue 07 November 2019 RT6512 9
General Safety Instructions
Indicates a hazardous situation which, if not prevented, will result in death or
serious injury.
Indicates a hazardous situation which, if not prevented, could result in death or
serious injury.
Indicates a hazardous situation which, if not prevented, could result in minor or
moderate injury.
Is used to address practices not related to physical injury.
Safety instructions (or equivalent) signs indicate specific safety-related
instructions or procedures.

Installation and Operation
Becker Avionics
10 RT6512 DV17501.03 Issue 07 November 2019
Disposal
The packaging material is inflammable, by burning, toxic fumes may develop.
This product contains materials that fall under the special disposal regulation. We recommend the
disposal of such materials in accordance with the current environmental laws.
•Dispose circuit boards by a technical waste dump which is approved to take on e.g.
electrolytic aluminium capacitors. Do under no circumstances dump the circuit boards with
normal waste dump.
Warranty Conditions
The device(s) may be installed on an aircraft only by an approved aeronautical
company (e.g. Part 145) which shall also examine the installation.
Any change made by the user excludes any liability on our part (excluding the work described in this
manual).
•The device must not be opened.
•Do not make any modifications to the device, except for those described in the manual.
•Make connections to the inputs, outputs and interfaces only in the manner described in
the manual.
•Install the devices according to the instructions.
We cannot give any guarantee for other methods.
Conditions of Utilization
With this device you bought a product which was manufactured and tested before delivery with the
utmost care.
Please take your time to read the notices which you ought to follow closely during installation and
operation.
Otherwise all claims under the warranty will become void and a decreased service life or even
damages must be expected.
The user is responsible for protective covers and/or additional safety measures in
order to prevent damages to persons and electric accidents.
Additional Conditions of Utilization
Please refer to "Safety-Conscious Utilization", page 20.
Non-Warranty Clause
We checked the contents of this publication for compliance with the associated hard and software. We
can, however, not exclude discrepancies and do therefore not accept any liability for the exact
compliance. The information in this publication is regularly checked, necessary corrections will be part
of the subsequent publications.

Becker Avionics
General Description
Introduction
DV17501.03 Issue 07 November 2019 RT6512 11
1 General Description
In this chapter you can read about:
1.1 Introduction.................................................................................................................................. 12
1.2 Purpose of Equipment................................................................................................................. 13
1.3 Variants Overview ....................................................................................................................... 13
1.4 Associated Devices..................................................................................................................... 13
1.5 Scope of Functionality................................................................................................................. 14
Receive Mode ................................................................................................................... 14
Transmit Mode .................................................................................................................. 14
Emergency Mode.............................................................................................................. 14
Audio Inputs and Outputs ................................................................................................. 15
Control Inputs.................................................................................................................... 16
Status and Control Outputs .............................................................................................. 18
Digital Interfaces to the Control Unit ................................................................................. 19
1.6 Safety-Conscious Utilization ....................................................................................................... 20
1.7 Restriction for Use....................................................................................................................... 20
1.8 Technical Data ............................................................................................................................ 21
General Characteristics .................................................................................................... 21
Typical Power Consumption ............................................................................................. 21
Receiver Data ................................................................................................................... 22
Transmitter Data ............................................................................................................... 23
Dimensions & Weight........................................................................................................ 23
Software ............................................................................................................................ 24
Hardware .......................................................................................................................... 24
Continued Airworthiness ................................................................................................... 24
Environmental Conditions ................................................................................................. 25
Certifications ..................................................................................................................... 26
1.9 Order Code.................................................................................................................................. 28
RT6512 ............................................................................................................................. 28
Accessories....................................................................................................................... 28
This manual describes the Becker Avionics remote-controlled VHF-AM transceiver RT6512-(XXX).
The type plate on your device shows the part number for identification purposes (see "Type Plate",
page 31).
Before starting operation of the device(s) please read this manual carefully, with particular attention to
the description referring to your device(s).

General Description
Becker Avionics
Introduction
12 RT6512 DV17501.03 Issue 07 November 2019
1.1 Introduction
The technical information in this document applies to the described product and variants of
RT6512-(XXX).
•We use also the term RT6512 for descriptions instead writing the complete model number.
•If a description refers to only one of the product variants its full name is used.
The manuals Maintenance & Repair (M&R) and Installation & Operation (I&O) contain the sections:
Section DV 17501.04
M&R
DV 17501.03
I&O
General Description X X
Installation X X
Operation Instructions X X
Theory of Operation X N/A
Maintenance and Repair X N/A
Illustrated Parts List X N/A
Modification and Changes X N/A
Circuit Diagrams X N/A
Certifications X N/A
Attachments X N/A

Becker Avionics
General Description
Associated Devices
DV17501.03 Issue 07 November 2019 RT6512 13
1.2 Purpose of Equipment
The remote-controlled VHF-AM transceiver RT6512 is made for installation with the related mounting
tray in the avionics compartment (non-pressurized and not temperature controlled) in all types of
aircraft.
The RT6512 is a simplex voice communication system in the standard avionics VHF frequency range
118.000...136.975 MHz (136.9916 MHz with 8.33 kHz channel spacing) or optional with extended
frequency range up to 155.975 MHz and uses standard amplitude modulation (A3E).
It can be operated by the Becker RCU6512 or RMU5000 using the RS422 control bus, or any OEM
control device using the ARINC 429 control bus with standard label format.
•The RT6512 can operate in 25 or 8.33 kHz channel spacing and is primarily for
aeronautical operational control (AOC) and air traffic services (ATS) safety
communications.
•The RT6512 uses ARINC 429 and RS422 interfaces for communication with a control
device.
•The RT6512 supplies frequency and mode control, either with the Becker RCU6512 or
RMU5000 controller using the RS422 communication port, or with any OEM product using
the standard ARINC 429 communication bus.
•The RT6512 has a high transmit power of 20 Wand can be used for communication over a
range of 200 NM direct line of sight.
1.3 Variants Overview
RT
6512
-
(
X
X
X
)
Type Identifier
0 – Standard
1 – with Emergency Mode
Model Number
0 - Standard
1 – Std. Freq. Range 118...136.975 MHz
2 – Ext. Freq. Range 118...155.975 MHz
1.4 Associated Devices
Following devices can operate with RT6512-(XXX):
Device
Function/Manufacturer
RCU6512
Becker Avionics Remote Control Unit
RMU5000
Becker Avionics Radio Management Unit
Control unit
Gables G7610 (Control unit for VHF-COMM only)
Control unit
Universal RCU
Glass cockpit
Genesys IDU680

General Description
Becker Avionics
Scope of Functionality
14 RT6512 DV17501.03 Issue 07 November 2019
1.5 Scope of Functionality
•The RT6512 is for AM (amplitude modulation) voice communication.
•The RT6512 does not include a control panel.
•Mechanics:
oThe case serves as heat sink:
oThe front side contains the main connector for connection to the aircraft wiring system,
and the antenna jack.
•Three front panel LEDs show basic information about overall equipment status.
Receive Mode
The RT6512 has a high-quality Class C, E and H2 receiver:
•It has a standard sensitivity of 5 µV, high dynamic range, and high blocking rejection.
•It can receive a weak signal while a 2nd VHF-AM transceiver in the same aircraft is
transmitting.
•The RT6512 can operate with offset carrier in 25 kHz and 8.33 kHz channel spacing.
Transmit Mode
The RT6512 has a high-quality Class 3 and 5 transmitters:
•The output power is 20 W under standard operating conditions (VSWR ≤1.5,
118...137 MHz).
•The output power is 18 W under standard operating conditions (VSWR ≤1.5,
137...156 MHz).
•The output power is at least 16 W under the specified environmental operating conditions
(when using antenna with VSWR≤2:1, for VSWR>3:1 output power decrease,
118...137 MHz).
•The output power is at least 14 W under the specified environmental operating conditions
(when using antenna with VSWR≤2:1, for VSWR>3:1 output power decrease,
137...156 MHz).
•The AM depth is >70% - standard value for airborne application.
•During transmission, the transmitter delivers a natural sidetone signal, which is available
on the LINE_OUT output (if enabled).
•The RT6512 has a protective function to prevent from blocking the frequency channel by a
stuck transmit button or a short circuit on the key line.
•The RT6512 supports status information if the device transmits through serial protocol
(RS422 and ARINC 429). This status can be used to inform the crew about stopped
transmission (as required by TSO-C128a/ETSO-2C128).
•The RT6512 transmitter has a protection from overheating. The VSWR on the antenna
connector is also monitored. See "Status and Control Outputs", page 18 for details.
Emergency Mode
•The RT6512-(201) variant supports Emergency Mode in which the device is automatically
tuned to emergency channel 121.500 MHz in 25 kHz channel spacing.
•External control of transceiver is prohibited with remaining device status monitoring.
Notice: Operators Remark
121.5 MHz = International voice aeronautical emergency.
123.1 MHz = International worldwide voice SAR use (e.g. Italy).

Becker Avionics
General Description
Scope of Functionality
DV17501.03 Issue 07 November 2019 RT6512 15
Audio Inputs and Outputs
1.5.4.1 Microphone Input
Figure 1: Standard Microphone Input Schematic
The RT6512can operate with standard microphones:
•Unbalanced,
•DC coupled,
•DC supplied from RT6512.
The bias current for standard microphone is drawn from RT6512 internal source 15 VDC through
series resistor 470 Ohm. The input audio signal is routed to a dynamic compressor keeping the
modulation factor limited over a wide input voltage range. The microphone input uses the cable guard
as ground compensation so microphone input shall be connected exactly as specified on Installation
diagrams.
1.5.4.2 Audio Input LINE IN
Figure 2: LINE_IN Schematic
The RT6512 symmetrical line input has no DC connection to ground. Input impedance is 600 Ω. The
maximum input level without clipping can be set as high as 6 V. The input audio signal is routed to a
dynamic compressor keeping the modulation factor limited over a wide input voltage range.

General Description
Becker Avionics
Scope of Functionality
16 RT6512 DV17501.03 Issue 07 November 2019
1.5.4.3 Audio Output LINE OUT
Figure 3: LINE_OUT
The audio output LINE OUT is symmetrical and has no DC connection to ground. If volume set to
maximum, the audio output power delivered is 100…125 mW into 600 Ωor 200 mW into 150 Ω.
Control Inputs
1.5.5.1 /ON (Unit Power ON/OFF Control)
/ON signal to set ON/OFF the RT6512.
The /ON line is used to activate an internal electronic switch to power-up the device.
It is active if the level on the /ON pin is less than 4.0 V or a resistance of less than 1 kΩconnects to
ground.
The /ON line is inactive if the level on the /ON pin is higher than 8.0 V or a resistance higher
than 50 kΩ connects to ground.
1.5.5.2 /PTT (Push-To-Talk)
/PTT is used to initiate transmission.
It is active when /PTT-input level is below 4.0 V, or a resistance to ground of less than 1 kΩ.
The /PTT line is inactive if the level on the /PTT-input is higher than 8.0 V, or a resistance higher
than 50 kΩconnects to ground.
1.5.5.3 /COM2 (Com Addressing Line)
/COM2 defines device sub address for ARINC communication.
The device detects a LOW state (Active state) on the /COM2 input when an external resistance of
lower than 1 kΩ is connected to ground.
The device detects a HIGH state (Inactive state) on the /COM2 input when an external resistance of
higher than 50 kΩ is connected to ground.
•Com addressing line bit:
oLOW (Active) state selects COM2.
oHIGH (Inactive) state selects COM1.
1.5.5.4 /SEL422 (Serial Interface Selection Line)
/SEL422 selects RS422 or ARINC 429 communication.
The device detects a LOW state (Active state) on the /SEL422 input when an external resistance of
lower than 1 kΩ is connected to ground.
The device detects a HIGH state on the /SEL422 input when an external resistance of higher
than 50 kΩ is connected to ground.
•Serial interface selection line:
oLOW (Active) state selects RS422.
oHIGH (Inactive) state selects ARINC.

Becker Avionics
General Description
Scope of Functionality
DV17501.03 Issue 07 November 2019 RT6512 17
1.5.5.5 /RX_ATT (External RX Attenuation Control)
/RX_ATT decreases the RF gain of the RX section by 20 dB to decrease cross talk effects.
The /RX_ATT line is used for an optional desensitization of the RT6512 receiver. The desensitization
can be required when a 2nd VHF-AM transceiver in the same aircraft is transmitting. In such case /PTT
line from 1st VHF-AM transceiver shall be connected to /RX_ATT input of 2nd device and /PTT from 2nd
device shall be connected to /RX_ATT input of the 1st device.
The /RX_ATT is active if /RX_ATT-input level is less than 4.0 V, or a resistance less than 1 kΩ
connects to ground.
The /RX_ATT line is inactive if the level on the /RX_ATT-input is higher than 8.0 V, or a resistance
higher than 50 kΩ connects to ground.
1.5.5.6 /SERV_EN (Enabling the Setup Modes)
/SERV_EN enables the setup modes.
/SERV_EN is a read/write access for all setup data, not available for standard user
The device detects a LOW state (Active state) on the /SERV_EN input when an external resistance of
lower than 1 kΩ is connected to ground.
The device detects a HIGH state (Inactive state) on the /SERV_EN input when an external resistance
of higher than 50 kΩ is connected to ground.
1.5.5.7 /TX-ENABLE (Enabling the TX)
/TX-ENABLE enables the transmitter.
The RT6512 detects a low state on the /TX_ENABLE input when an external resistance lower than
1 kΩ connects to ground.
The RT6512 detects a high state on the /TX_ENABLE input when an external resistance higher
than 50 kΩ connects to ground. In such case transmission is permanently blocked.
For an aircraft installation /TX-ENABLE input shall be connected to ground
directly on the main connector. /TX-ENABLE line cannot be routed as part
of installation cable bundle.
Notice: Do not apply DC voltage above 5 Volts to /TX_ENABLE to prevent
device damage!
1.5.5.8 /EMERG (Enabling the Emergency Mode)
/EMERG enables the Emergency Mode for variant –(201) only.
The RT6512-(201) detects a low state on the /EMERG input when an external resistance lower than
1 kΩ connects to ground. In such case transceiver activates Emergency Mode operation.
The RT6512-(201) detects a high state on the /EMERG input when an external resistance higher
than 50 kΩ connects to ground.

General Description
Becker Avionics
Scope of Functionality
18 RT6512 DV17501.03 Issue 07 November 2019
Status and Control Outputs
1.5.6.1 /FAILURE
Figure 4: /FAILURE Output Schematic
This /FAILURE output is coupled to the status shown at the status LEDs at the connector side of
RT6512. It agrees to the OR function of the red and the yellow LEDs. When the test function is not
ok, the transistor in the /FAILURE output is ON.
This output is an open collector (drain) type with capability to:
•Pull maximum 100 mA current to ground with a voltage drop of less than 2.5 V (related LEDs
are on).
•Pull maximum 0.1 mA current to ground for output voltage 28.0 V when in "inactive" state
(related LEDs are off).
It can be used to drive an external relay if 100 mA output current limit at the supply voltage 28.0 V is
not sufficient. This /FAILURE output has a protection against spikes produced from a relay. See
"Status & Error Indication", page 56.
1.5.6.2 RX_AGC (AGC Voltage of the RX-RF-AGC)
The AGC output is a DC coupled output of the RF-AGC used in the receiver.
The output voltage varies monotonic in the range of 0...5 V, when the input level at the antenna input
is varied from -105...+13 dBm.
For all antennas input levels from -120...-105 dBm the output voltage is positive and not higher than
the output voltage which can be obtained at -105 dBm.
1.5.6.3 /SQL_EVAL
This digital output shows that the audio signal from the receiver is available on the LINE_OUT.
This output is an open collector type with capability to:
•Pull maximum 100 mA current to ground with a voltage drop of less than 2.5 V (related LED(s)
is on).
•Pull maximum 0.1 mA current to ground for output voltage 28.0 V when in "inactive" state
(related LEDs are off).
•It can be used to drive an external relay, if 100 mA output current limit at the supply
voltage 28.0 V is not sufficient.
•This /SQL_EVAL output has a protection against spikes produced from a relay.
•RX indication inactive (HIGH):
oSquelch ON but no audio goes out on LINE_OUT.
oRT6512 in TX mode.
•RX indication active (LOW), only possible in RX mode:
oSquelch ON and audio goes out on LINE_OUT.
oSquelch OFF (permanent audio out on LINE_OUT).

Becker Avionics
General Description
Scope of Functionality
DV17501.03 Issue 07 November 2019 RT6512 19
Digital Interfaces to the Control Unit
1.5.7.1 Interface ARINC 429
Name
Function / Remarks
ARI429_RX_A1
1st ARINC 429 Interface RX Line A
ARI429_RX_B1
1st ARINC 429 Interface RX Line B
ARI429_TX_A1
1st ARINC 429 Interface TX Line A
ARI429_TX_B1
1st ARINC 429 Interface TX Line B
ARI429_RX_A2
2nd ARINC 429 Interface RX Line A
ARI429_RX_B2
2nd ARINC 429 Interface RX Line B
ARI429_TX_A2
2nd ARINC 429 Interface TX Line A
ARI429_TX_B2
2nd ARINC 429 Interface TX Line B
1.5.7.2 Interface RS422
Name
Function / Remarks
RS422_RX+
RS422 Interface RX Line B (high if idle)
RS422_RX-
RS422 Interface RX Line A (low if idle)
RS422_TX+
RS422 Interface TX Line B (high if idle)
RS422_TX-
RS422 Interface TX Line A (low if idle)

General Description
Becker Avionics
Restriction for Use
20 RT6512 DV17501.03 Issue 07 November 2019
1.6 Safety-Conscious Utilization
The device(s) may be installed on an aircraft only by an approved aeronautical
company (e.g. Part 145) which shall also examine the installation.
•The installation of the device into an aircraft may be carried out only by
an authorized installation company. The country regulations always have
to be obeyed.
•Use the product only within the specified conditions, see "Technical
Data", page 21.
•Power supply:
oDo not connect the device to AC sources.
oMake sure that the device is connected to the mandatory DC source,
see "Technical Data", page 21.
oDo not connect the device with reversed polarity to the DC source.
•Circuit breaker:
oUse the recommended fuse in the power supply line for protection of
the application, see "Technical Data", page 21.
Cleaning:
•Do not use aggressive cleaning agents e.g. Acetone.
oThese cleaning agents can cause damages.
Excessive pulses on the DC bus of the aircraft may cause damage on electrical
circuits of any installed instrument.
Do not power-on the device during engine start or shutdown.
1.7 Restriction for Use
The product is to be used inside the declared limits.