Park Air Systems T6T User Documentation

T6T VHF 100 W Transmitter

User Documentation

Page ii T6T VHF 100 W Transmitter

Handbook Title: T6T VHF 100 W Transmitter User Documentation
Handbook Part Number: 31-3T6T100V
Handbook Version: 2.0
Date of Issue: February 2005
Equipment Modification Level 7
Published By: Park Air Systems

Northfields
Market Deeping
Peterborough PE6 8UE
England

Telephone: From UK, 01778 345434

From outside UK, 44 1778 345434

Fax: From UK, 01778 342877

From outside UK, 44 1778 342877

www.parkairsystems.com

Errata

Any errors found in this handbook are promulgated through the Park Air FTP network. Any
user can access this information by logging on to:

ftp.parkairsystems.com

When logged on, select the public (Pub) folder, then the Handbook Errata Sheets folder,

and then select the required equipment model.

[Adobe Acrobat™ must be loaded on your PC to use this facility]

T6T VHF 100 W Transmitter Page iii

Health and Safety

Warnings

A warning is used to indic ate possibl e danger to per sonnel. Th roughout Par k Air hand books, warni ngs
are indicated by the following symbols:

Cautions

A caution is used to indicate possible danger to the equipment.

Trademarks

The following tradenames are used in this handbook.

IBM This is a registered trademark of International Business Machines.
Microsoft This is a registered trademark of Microsoft Corporation in the USA and other

countries.

Windows This is a registered trademark of Microsoft Corporation in the USA and other

countries.

Indicates electrical danger to personnel.WARNING

Indicates a hazardous material.

WARNING

Indicates a non-ionizing radiation hazard.

WARNING

Indicates a specified danger to personnel.

WARNING

Indicates the presence of electrostatic sensitive devices (ESSD). Caution

Indicates a specified danger to the equipment. Caution

Page iv T6T VHF 100 W Transmitter

List of Abbreviations

ac alternating current
AGC automatic gain control
AM amplitude modulation
ATC air traffic control
BER bit error rate
BIT built-in test
C celsius
CD compact disk
dB decibel
dc direct current
DSB double sideband
E-BIT external bit signal
ESSD electrostatic sens iti ve devi ces
Fig figure
FM frequency modulation
Hz hertz
IF intermediate frequency
kg kilogramme
kHz kilohertz
LCD liquid crystal display
mmetre
mA milliamp
MARC multi-access remote control
mm millimetre
mW milliwatt
MHz megahertz
MSK minimum shift keying
PA power amplifier
PC personal computer
PCB printed circuit board
pk-pk peak-to-peak
ppm parts per million
PSU power supply unit
PTT press to transmit

RF radio frequency
ROM read-only memory
RSE2 remote site equipment
RSSI receiver signal strength indication
Vvolt
VFP virtual front panel
VHF very high frequency
VOGAD voice-operated gain adjusting device
VSWR voltage standing wave ratio
Wwatt

Approvals and Standards T6T VHF 100 Watt Transmitters

Approvals:

The equipment is designed to meet the essential requirements of Directives
1999/5/EC, 89/336EEC as amended by Directive 93/68/EEC, and 72/23/EEC.

Standards:

The following standards are applied:

EMC EN 301 489-1; EN 301 489-22.

Health & Safety, EN 60950, CAN/CSA-C22.2 No. 60950, UL 60950.

Radio EN 300 676, IC RSS141, FCC part 15 and 87.

Telecom CS-03.

FCC Statement:

This device has been tested and found to comply with the limits for a Class B digital
device, pursuant to part 15 of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference in a residential installation.
This equipment generates, uses and can radiate radio frequency energy and, if not
installed and used in accordance with the instructions, may cause harmful
interference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation.
If this equipment does cause harmful interference to radio or television reception,
which can be determined by turning the equipment off and on, the user is
encouraged to try to correct the interference by one or more of the following
measures:

-Reorient or relocate the receiving antenna.

-Increase the separation between the equipment and the receiver.

-Connect the equipment into an outlet on a circuit different from that to which the
receiver is connected.

-Consult the supplier or an experienced radio/TV technician for help.

Operation on 8.33 kHz channel spacing is restricted to European customers.

Page vi T6T VHF 100 W Transmitter

About This Hard Copy

This document, apart from th e preface, is a hard copy of the files contained on the CD and co mprises
the following parts:

Preface (not on CD)
Introduction
Specification
Operation
Installation
Maintenance.

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Introduction

This topic gives a brief introduction to the T6T VHF 100 W Multimode Transmitter.

T6T VHF 100 W Transmitter Page 2 Introduction

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Purpose

The T6T VHF multimode 100 W transmitter i s intended for use in fix ed ground environm ents such as
airports and en-route centres. The transmitter operates in voice and ICAO defined data modes at
frequencies between 118 and 136.975 MHz.

Dependent on the software loaded into the radio, the following operating modes can be selected:

❑ AM-Voice. All transmitters have this mode
❑ AM-MSK (optional)
❑ Mode 2 (optional)
❑ Mode 3 (optional).

Fig 1 T6T VHF 100 W Transmitter

Models and Part Numbers

The following table identifies the T6T VHF 100 W transmitters:

Mechanical Installation

The transmitter fits i nto a n i ndu st rial st andard 19 inch (483 mm) e qui pme nt c ab inet and occupies 4U of
space.

Description Part Number Frequency Range Channel

Spacing

(AM-Voice)

Special

Applications

T6T 100 W standard
frequency coverage high
stability transmitter

B63100HS/NB 118 to 136.975MHz 25 kHz or

8.33 kHz

Supports 5-offset
carrier operation

T6T VHF 100 W Transmitter Page 3 Introduction

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Frequency Selection

T6 radios operate with 8.33 kHz and 25 kHz channel spacing. The radios recognize frequencies entered
in ICAO format and automatic ally ad just to t he correc t channe l spacing. For m ultichan nel operati on up
to 100 preset frequency cha nnels can be stored in the radio for immediate recall; any combina tion of

8.33 kHz and 25 kHz channel spacing can be stored. Any valid operating frequency can be selected from
the radio’s front panel or a compatible remote control equipment.

Operating Parameters

The transmitter’s o perat ing parameters are set usi ng th e fr on t pa nel mu lti -pur po se Sc r oll/S ele ct switch,
or by using the Park Air Virtual Front Panel (VFP) software in conjunction with a Personal Computer (PC).

Virtual Front Panel

The Virtual Front Panel (VFP) software supplied on CD with the radio is compatible with any PC or laptop
running Windows 2000™ or Windo ws XP ™. T he VFP allo ws ch ang es to a rad io’s setti ngs and cha nnel
information, it dis plays the current B IT state, display s BIT history, allo ws security lo cks to be set, and
provides maintenance facilities. A typical VFP presentation is shown in Fig 2. Usi ng th e VFP has s ever al
advantages over setting a radio from the front panel; these are:

❑ A profile of the operationa l setti ngs an d chann el inform ation c an be crea ted, sto red on di sk, and

then recalled to download into other radios.

❑ A print out of the radio’s profile can be made from the VFP.
❑ The front panel controls can be locked. Front Panel Lock is available only when using the VFP.

Fig 2 Typical VFP Presentation

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Intentionally Blank

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Specification

This section gives the specification applicable to the T6T VHF 100 W Multimode Transmitter
operating in AM modes, Mode 2 and Mode 3.

All radios operate in AM-Voice mode. Additional software must be loaded to allow AM-MSK,
Mode 2 and Mode 3 operation.

T6T VHF 100 W Transmitter Page 2 Specification

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General Specification

The general specific ation app lies to the T6T 100 watt transm itter irre spective of the sele cted oper ating
mode. Separate listings are given for AM modes, Mode 2 and Mode 3. One model of the T6T VHF 100 W
Multimode Transmitter is available as detailed in Table 1.

Frequency accuracy

The frequency accuracy is better than 0.3 ppm.

Number of Channels

The transmitter has a multichannel capability. 100 channels can be stored and recalled.

Power Requirements

The transmitter operates from an ac mains supply, or a dc input supply. When both supplies are
connected, the dc input acts as an automatic backup for the ac mains.

ac input supply The transmitter opera tes from a 48 to 62 Hz single-phase ac supply

and automatically adjusts to operate from any supply voltage ranging
from 110 Vac to 230 Vac ±10%. The power consumption figures are
given in Table 2.

dc input supply The transmitter operates from a dc input supply between 21.6 and

32 V (measured at the radio’s input). Current loading is given in
Table 2.

Table 1 100 Watt T6 Transmitter

Description Part Number Frequency Range Special Applications

100 watt, high stability, standard
frequency coverage transmitter

B63100HS/NB 118 to 136.975MHz Supports 5-offset carrier

operation

Table 2 Power Consumption

Requirement 100 Watt Trans mitte r Normal Operation

ac dc

Maximum 1000 VA 24 A
Typical 600 VA 17 A
Not Transmitting 90 VA 1.5 A

T6T VHF 100 W Transmitter Page 3 Specification

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Dimensions and Weight

The dimensions and weight of the 100 watt transmitter are:

Width 483 mm (19 inches).
Height 177.8 mm (7 inches). The height occupies 4U of equipment cabinet

space.

Depth 430 mm (16.9 inches) measured from front panel to rear panel.

465 mm (18.3 inches) measured from front panel to rear RF
connectors.

Weight 25 kg (55 pounds).

Environmental

Temperature range The transmitter operates to specification across the temperature

range of -20°C to +55°C.
The transmitter can be stored at temperatures ranging from

-30°C to +70°C without causing any damage.

Humidity The transmitter operates to specification at a relative humidity

between 5% and 90% non-condensing.

Altitude The transmitter operates to specification up to 15,000 feet.

Additionally it is capable of storage at altitudes up to 50,000 feet
without damage.

Shock and vibration The transmitter complies with shock and vibration protection

MIL-STD-810E, method 516.4, procedure VI - Bench Handling.

Ventilation The transmitter is cooled by integral fans, which normally runs at half

speed. At an RF PA temperature of 45°C this is increased to full speed
and at 40°C it reduces to half speed again.

The transmitter power supply units also use internal fans.

Warm up time The transmitter is fully operational within 20 seconds but can take up

to 10 minutes to achieve frequency accuracy for offset carrier.

T6T VHF 100 W Transmitter Page 4 Specification

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AM Modes

The transmitter can operat e in A M- Vo ice mo de ( st anda rd) and A M-MS K mo de ( opti on al). T he fo ll owing
specifications apply to both modes unless stated otherwise.

Transmitter RF Characteristics

RF Power Output

The RF car rie r ou t p ut po we r i s ad j us t ab le in 2 W steps from 10 W t o 1 0 0 W.As an option, the ma ximu m
selectable power can be limited. Output power is automatically controlled under the following conditions:

Frequency range Variations in power remain within 0 to +1 dB over the operational

frequency range.

Low supply voltage Variations in power remain within ±1 dB for supply voltages between

24 Vdc and 32 Vdc.

High VSWR Loop error can reduce power progressively by up to 3 dB. Variations

in power remain within ±1 dB into a VSWR of up to 2.5:1. At a VSWR
greater than this the output power may be reduced by 10 dB ±1 dB.

High RF PA temperature If the RF PA temperature sensor exceeds 80°C the output power is

reduced by 3 dB ±1 dB. If the RF PA temperature sensor exceeds
90°C the transmitter is de-keyed and automatically re-keyed at 70°C.

PA Module Failure If one of the two PA modules fails, the transmitter will continue to

operate at half power, 50 watts.

Duty Cycle

Both modes 100% continuous operation.

Channel Spacing

AM-Voice mode The transmitter is capable of both 25 kHz channel spacing and

8.33 kHz channel spacing.

AM-MSK mode 25 kHz.

Offset Carrier

AM-Voice mode The transmitter is capable of offsetting the carrier frequency to provide

2, 3, 4 and 5-carrier offset.

AM-MSK mode Offset carrier is not available.

Harmonic Outputs

Both modes Second harmonic outputs are less than -36 dBm, third harmonic

outputs are less than -46 dBm and fourth harmonic outputs and above
up to 4 GHz, are less than -56 dBm.

T6T VHF 100 W Transmitter Page 5 Specification

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Spurious Outputs

Both modes The spurious outputs are less than -46 dBm for modulation depths up

to 90%, measured at greater than 500 kHz from carrier in the
frequency range 9 kHz to 4 GHz. There are no coherent spurious
outputs above the spectral mask at less than 500 kHz.

Intermodulation

Both modes Intermodulation products, caused by an interfering signal with the

same power as the transmitter isolated by 30 dB, are at least -40 dBc
at ≥±150 kHz and -50 dBc at ≥±500 kHz.

Transmitter Modulation Characteristics

The transmitter modulation characteristics are as follows:

Mode

AM-Voice AM-Voice mode uses Double Sideband (DSB) Amplitude Modulation

(AM) full carrier; emission designator 6K80A3EJN for 25 kHz
channels and 5K00A3EJN for 8.33 kHz channels.

AM-MSK AM-MSK mode uses Double Sideband (DSB) Amplitude Modulation

(AM) full carrier; emission designator 13K0A2DJN.

Modulation Depth

Both modes The transmitter is capable of modulation depths up to 95%.

Hum and Noise

Both modes The hum and noise is more than 45 dB below the signal level for line

input levels <-13 dBm, and more than 50 dB below the signal level for
line input levels ≥-13 dBm, for a carrier modulated by a 1 kHz signal
with a modulation depth of 90%.

Frequency Response

25 kHz channel spacing AM-Voice and AM-MSK: The variation in frequency response with

reference to a 1 kHz signal is within +0.5 dB and -1.5 dB across the
frequency range 300 to 3400 Hz. The response is also less than

-20 dB at 100 Hz and below, and less than -30 dB at 4 kHz and above.

8.33 kHz channel spacing AM-Voice only: The variation in frequency response with reference to
a 1 kHz signal is within +0.5 dB and -1.5 dB across the frequency
range 350 Hz to 2500 Hz. The response is also less than -10 dB at
100 Hz and below, and less than -30 dB at 3200 Hz and above.

Distortion

25 kHz channel spacing The total harmonic distortion is less than 5% due to signals with a

modulation depth of 90%, within the frequency range 300 Hz to
3400 Hz.

8.33 kHz channel spacing AM-Voice only: The total harmonic distortion is less than 5% due to
signals with a modulation depth of 90%, within the frequency range
350 Hz to 2500 Hz.

T6T VHF 100 W Transmitter Page 6 Specification

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Residual FM

Both modes For a test signal of 1 kHz set at 80% modulation depth applied to the

line input of the transmitter, the unwanted peak frequency modulation
does not exceed ±500 Hz.

VOGAD

AM-Voice The VOGAD has an operational range of 30 dB. The VOGAD can be

disabled.

AM-MSK The VOGAD is disabled.

Mute

AM-Voice The mute level is set at 15 dB below the average speech line level

setting. The mute can be disabled.

AM-MSK The mute is disabled.

Differential Group Delay

AM-MSK There is less than 60 µs differential group delay for signals in the

range 1200 to 2400 Hz.

Transmitter Control

Transmitter cont rol characteristics are as follows:

Audio Inputs

Voice can be connected to the tr ansmitter via the front pan el micr ophon e connec tor. Vo ice can als o be
connected via the line inputs. Line level setting from -30 to +10 dBm.

PTT Time Ou t

The time out period is adjustable from 2 to 510 seconds in 2 second steps or it can be disabled.

T6T VHF 100 W Transmitter Page 7 Specification

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Mode 2

This section gives the tran smitt er spe cificati on appl icable to Mo de 2 oper ation. Mo de 2 paramete rs are
identical to AM-Voice mode parameters with the following exceptions:

RF Power Rise Time

The transmitter pr oduces more than 90% of ful l power output within the first 2 symbols of th e power
stabilization segment, which is the first segment of the training sequence and consists of 4 symbols each
representing 000.

RF Power Decay Time

The output power decays by more than 20 dB within 2.5 symbols of the middle of the final symbol.

Channel Spacing

25 kHz channel spacing only.

Transmitter Modulation Characteristics

Mode 2 uses Carrier Sense Multiple Access (CSMA) differentially encoded 8-phase shift keying
(D8PSK), using a raised cosine filter with α=0.6 (nominal value), emission designator 14K0G1DE.
Information is differentially encoded with 3 bi ts p er symb ol transmitted as changes i n pha se ra ther th an
absolute phase. Th e data stream i s divided into g roups of 3 con secutive data bit s, least signi ficant bit
first. Zeros are padded to the end of transmissions if needed for the final channel symbol.

Modulation Rate

The symbol rate is 10,500 symbols/second (±0.005%), resulting in a nominal bit rate of 31,500 bits/s.

RMS Phase Error

The RMS phase error is less than 3°. The error vector magnitude is less than 6%.

Phase Acceleration

The total frequency change during the transmission of the unique word is less than 10 Hz. After this, the
phase acceleration is less than 500 Hz/s.

T6T VHF 100 W Transmitter Page 8 Specification

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Mode 3

This section gives the tran smitt er spe cificati on appl icable to Mo de 3 oper ation. Mo de 3 paramete rs are
identical to AM-Voice mode parameters with the following exceptions:

RF Power Rise Time

The transmitter pr oduces more than 90% of ful l power output within the first 2 symbols of th e power
stabilization segment, which is the first segment of the training sequence and consists of 4 symbols each
representing 000.

RF Power Decay Time

The output power decays by more than 20 dB within 2.5 symbols of the middle of the final symbol.

Channel Spacing

25 kHz channel spacing only.

Transmitter Modulation Characteristics

Mode 3 uses Time Division Multiple Access (TDMA) differentially encoded 8-phase shift keying (D8PSK),
using a raised cosine filter with α=0.6 (nominal value), emission designator 14K0G7WET. Information is
differentially encoded with 3 bits per symbol transmitted as changes in phase rather than absolute phase.
The data stream is div ided into groups of 3 consecutiv e data bits, least significant bi t first. Zeros are
padded to the end of transmissions if needed for the final channel symbol.

Modulation Rate

The symbol rate is 10,500 symbols/second (±0.005%), resulting in a nominal bit rate of 31,500 bits/s.

RMS Phase Error

The RMS phase error is less than 3°. The error vector magnitude is less than 6%.

Phase Acceleration

The total frequency change during the transmission of the unique word is less than 10 Hz. After this, the
phase acceleration is less than 500 Hz/s.

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Operation

This topic describes the transmitter’s operating controls and indicators.

It also details how to set up the transmitter’s operating parameters.

T6T VHF 100 W Transmitter Page 2 Operation

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Controls, Indicators and Front Panel Connectors

This section describes the transmitter’s controls, indicators and front panel connectors.

Front Panel

The transmitter’s front panel is illustrated below.

Scroll/Select Switch and LCD

The Scroll/Select switch is used in conjunction with the LCD to select most of the transmitter's operational
settings. During normal operation, the LCD sh ows the o perating fr equency, the channel number (if t he
channel store facili ty is used), the carrier offset (if us ed), and displays a graphical rep resentation of
instantaneous peak power.

The example LCD s creen above show s the transmitter o perating on 11 8.000 MHz; the fr equency has
been preset as channel 100 and offset at +7.3 kHz.

Ready Indicator

A green indicator that lights when the transmitter is ready for use and no BIT faults have been detected.

Transmit Indicator

An amber indicator that lights when the transmit circuit is keyed and producing output power.

Alarm Indicator

A red indicator that either flashes, or lights, when a BIT fault has be en detected. BIT indications are
classified as either Alarms or Alerts.

If an ‘alert’ conditi on is detected, the Alarm indi cator flashes, the Ready i ndicator remains lit, and t he
transmitter remains operational. A BIT ‘alert’ is indicated if:

❑ The transmitter RF output power has reduced from its setting by more than 1 dB but not more than

3 dB.

❑ The supply volts falls below a pre-defined level.

Any other BIT condit ion results in an al arm. When detected, the Alarm indicator l ights and the Ready
indicator becomes unlit; the transmitter cannot be used.

READY

ALARM

TRANSMIT

STANDBY

SCROLL/

SELECT

MICROPHONE/
DIAGNOSTICS

REFERENCE

F r e q 1 1 8 .0 0 0 M H z
C h 1 0 0 + 7 . 3 k H z

P w r

Scroll/Select SwitchLCD

M o d e A M V o i c e 1

T6T VHF 100 W Transmitter Page 3 Operation

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Standby Indicator

A red indicator that lights whe n the transm itter i s in standby mode. Whe n in stand by mode , most of the
radio's circuits are inactive, the front panel LCD is blanked, and the transmitter cannot be keyed.

Standby mode is selected and deselected using the front panel Scroll/Select switch and LCD, by initiating
an instruction thro ugh a MARC system, th rough a T6 control ler or thro ugh th e VFP. For d etails of front
panel selection and deselection see page 14.

Reference Connector

An SMB jack socke t that allows a freq uency counter to moni tor the transmitter 's reference frequency .
This connector is used onl y for maintenan ce purpos es. The instr uctions for ch ecking and adjusting the
reference frequency are given in the Maintenance section.

Microphone/Diagnostics Connector

A dual purpose conne ctor that a llows either a m icro phone, o r a PC, to be c onnec ted to the transmi tter.
The connector is a 7-pin self-locking DIN socket; the pin-out is shown in Table 1.

A microphone is fitted to this c onnec tor to enab le the tra nsmit ter to be ope rated in AM loca l mode. T he
connections are detailed in Table 1. A PC can also be connected to allow the VFP to be displayed. Using
the VFP is detailed in t he Maintenance section. The PC connections at the transmitter are shown in
Table 2 on the following page.

Table 1 Microphone/Diagnostics Connector - Audio Connections

Pin

Number

Signal

Input or

Output

Description

1 Microphone ground - 0 V.
3 Microphone PTT Input 0 V to PTT.
5 Sidetone Output 0 to 3 V pk-pk.
6 Microphone input Input 2 to 35 mV rms on Passive setting and 8 to 140 mV rms on

Active setting to remain in VOGAD range.

7Ground - 0V.

Table 2 Microphone/Diagnostics Connector - PC Connections

Pin

Number

Signal

Input or

Output

Description

2 Transmit data Output RS232, 115200 baud, 8 data bits, 1 stop bit, no parity, no

handshaking.

Viewed from front

T6T VHF 100 W Transmitter Page 4 Operation

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Rear Panel Power Switch

The rear panel power switch is a 2-way rocker switch used to select between power on, and standby.

When the Power switch is set to the Standby position, dangerous voltages are still present
in the transmitter's internal power supply circuitry. To ensure safe working, the transmitter
must be isolated from the ac and dc input supplies.

4 Receive data Input RS232, 115200 baud, 8 data bits, 1 stop bit, no parity, no

handshaking.

7 Ground - 0 V.

Table 2 Microphone/Diagnostics Connector - PC Connections

Pin

Number

Signal

Input or

Output

Description

WARNING

Dangerous Voltages

= Standby= On

T6T VHF 100 W Transmitter Page 5 Operation

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Setting Up and Operation

Introduction

Setting up the transmi tter involves using the front panel Sc roll/Select switch to specify the op erating
parameters.

Operating parameters can also be set using the Virtual Front Panel (VFP), through a Multi-Access
Remote Control (MARC) system , from an associat ed T6 controlle r. VFP operation is described on thi s
disk under Maintenance; MARC and T6 controller functionality is described in separate handbooks.

Table 9 on page 32 details the functions and parameters that can be set from all sources.

No attempt to set up the transmitter should be made until the installation procedures, given in the
Installation topic, are completed.

Normal Operation

During normal operation, the LCD displays the Main screen. This screen shows the operating frequency,
the channel number (if th e channel store facility is used), the car rier offset (if used), and displays a
graphical representation of output power when the transmitter is keyed. If the transmitter has been set to
Standby mode, which is shown by the front panel Standby indicator being lit, the LCD is blanked.

Using the Scroll/Select Switch

The Scroll/Select switch (refe rred to throughout this sect ion as the ‘Switch’) is used to leav e the Main
screen and display the Control screen (see page 8). Furth er use of t he Swit ch d ispla ys va rious s ele ction
menus and allows the r equired parameters to be set. The s witch has three actions: it can be tu rned
clockwise, anti-clockwise, or momentarily pushed in.

READY

ALARM

TRANSMIT

STANDBY

SCROLL/

SELECT

MICROPHONE/
DIAGNOSTICS

REFERENCE

F r e q 1 1 8 .0 0 0 M H z
C h 1 0 0 + 7 . 3 k H z

P w r

Scroll/Select SwitchLCD

M o d e A M V o i c e 1

T6T VHF 100 W Transmitter Page 6 Operation

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Screen Protocol

The following protocol is applicable to all screens described in this document.

Main Screen During normal operation, the Main screen (an example of which is shown below

whilst the transmitter is transmitting) is displayed.

Switch Refers to the front panel Scroll/Select switch. The switch is turned clockwise to scroll

through fields from left to right, and from top to bottom. The switch is turned
anti-clockwise to scroll through fields from right to left, and from bottom to top. The
switch is pressed to make a selection.

Time out If during any setting up procedure the Scroll/Select switch is not operated for

30 seconds, the display returns to the Main screen. If editing any parameter has not
been completed, the transmitter stays on the original setting.

>> Indicates more fields are available other than those currently displayed. To access

those fields, turn the switch clockwise through the last displayed field.

<< Indicates more fields are available other than those currently displayed. To access

those fields, turn the switch anti-clockwise through the first displayed field.

Back When Back is selected, you are returned to the previous menu.
Exit When Exit is selected, you are returned to the Main screen.

Menu System

The front panel control of the radio is implemented through a hierarchical menu system as shown on the
following page.

F r e q 1 1 8 . 0 0 0 M H z
C h 1 0 0 + 7 . 3 k H z
M o d e A M V o i c e
P w r I I I I I I I I I I

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Menu System

F r e q 1 1 8 . 0 0 0 M H z
C h 1 0 0
M o d e A M V o i c e
P w r I I I I I I I I I I

Settings

Set the

transmitter

operational

settings

BIT

Initiate a BIT

test and view

results

Standby

Enter or Exit

standby mode

Ref Freq

Adjust the

transmitter

reference

frequency

Band Edges

Set up the

transmitter

band edges

Polarities

Set the active

polarity for

certain hardwire

connections

Backlight

Adjust the

display’s
backlight

AM-Voice Mode

Settings

(see page 17)

AM-MSK Mode

Settings

(see page 19)

Digital Modes
(see page 20)

Mode and

Mode

Settings

Select Mode

Menu Lock Screen

Main Screen

(Example)

Displayed during normal

transmitter operation

Frequency

Set the

transmitter

operating
frequency

Channel

Set or recall up

to 100 preset

frequency

channels

Control Screen

Configure the transmitter

operating parameters, ac cess

the BIT facility or view the

software configuration

.

S/W Config

View the

transmitter

software

configuration

T6T VHF 100 W Transmitter Page 8 Operation

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Menu Lock Screen

A security facility available only from the VFP allows the transmitter front panel to be ‘locked’. When this
facility is active, no oper ational sett ings can be made fr om the front panel u ntil an ‘unlo ck’ command is
sent from the VFP.

The following screen is displayed when ‘lock’ is active, and the front panel switch is pressed.

To exit the system lock screen:

❑ Select OK, then press the switch. You are returned to the Main screen.

or,

❑ Wait for the 30 second time out to expire. You are returned to the Main screen.

Control Screen

The Control screen is ente red from the Main screen by pressin g the switch. The following screen is
displayed:

S E C U R I T Y M E S S A G E

F r o n t P a n e l

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Change the transmitter operating frequency.

Store or recall preset channel frequencies.
Select operating mode and mode se ttin gs .

Initiate a BIT test and view results.

View software configuration.

Enter or exit standby mode.

T6T VHF 100 W Transmitter Page 9 Operation

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Main Page

Notes for Setting Up the Transmitter

The following notes should be read before setting up the transmitter. They advise on the special
frequency display when using 8.33 k Hz channel spacing, and give guidan ce on the optim um line leve l
settings. Note that for operation in the United States of America, this equipment is certified only for
operation using 25 kHz channel spacing.

Front Panel Display for 25 kHz and 8.33 kHz Channel Spacing

When setting the op erating fr equency of the trans mitter and 8.33 kHz channel s pacing is require d, the
displayed frequency differs from the actual channel frequency. Table 3 shows the pattern used for
25 kHz and 8.33 kHz spaced channel frequencies from 118.000 MHz to 118.141 MHz. The pattern is the
same for any frequency within the transmitter's frequency range. The display conforms to ICAO
convention for 8.33 kHz operation.

Table 3 25 kHz and 8.33 kHz Channel Spacing Displays

Actual Frequency

(to 4 decim al places)

Channel Spacing Displayed Frequency

at Transmitter's Front Panel

118.0000 MHz

118.0000 MHz

118.0083 MHz

118.0166 MHz

118.0250 MHz

118.0250 MHz

118.0333 MHz

118.0416 MHz

118.0500 MHz

118.0500 MHz

118.0583 MHz

118.0666 MHz

118.0750 MHz

118.0750 MHz

118.0833 MHz

118.0916 MHz

118.1000 MHz

118.1000 MHz

118.1083 MHz

118.1166 MH z

118.1250 MHz

118.1250 MHz

118.1333 MHz

118.1416 MHz

25 kHz

8.33 kHz

8.33 kHz

8.33 kHz

25 kHz

8.33 kHz

8.33 kHz

8.33 kHz

25 kHz

8.33 kHz

8.33 kHz

8.33 kHz

25 kHz

8.33 kHz

8.33 kHz

8.33 kHz

25 kHz

8.33 kHz

8.33 kHz

8.33 kHz

25 kHz

8.33 kHz

8.33 kHz

8.33 kHz

118.0 00 MHz

118.005 MHz

118.010 MHz

118.015 MHz

118.0 25 MHz

118.030 MHz

118.035 MHz

118.040 MHz

118.0 50 MHz

118.055 MHz

118.060 MHz

118.065 MHz

118.0 75 MHz

118.080 MHz

118.085 MHz

118.090 MHz

118.1 00 MHz

118.105 MHz

118.110 MHz

118.115 MHz

118.1 25 MHz

118.130 MHz

118.135 MHz

118.140 MHz

T6T VHF 100 W Transmitter Page 10 Operation

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Main Page

Line Level Setting

The input line leve l s ett ing di spl ayed on the front panel is equ iv al ent to th e av erage speech level with a
peak-to-average ratio of 13 dB. This corresponds to the level specified for the lines.

When testing the transmitter using a sine wave, the line input level should be set to 10 dB above the line
level setting. The VOGAD and mute thresholds are preset at 10 dB and 15 dB respectively below the line
level setting.

Table 4 shows the relationship between the input line level, VOGAD threshold and mute threshold.

Table 4 Relationship Between Line Level, VOGAD Threshold and Mute Threshold

Line Level Setting

(dBm)

Average Speech

Level (dBm)

Sine Wave Level

(dBm)

VOGAD Threshold

(dBm)

Mute Threshold

(dBm)

+10 +10 +20 0 -5

+5 +5 +15 -5 -10

00+10-10-15

-5 -5 +5 -15 -20

-10 -10 0 -20 -25

-15 -15 -5 -25 -30

-20 -20 -10 -30 -35

-25 -25 -15 -35 -40

-30 -30 -20 -40 -45

T6T VHF 100 W Transmitter Page 11 Operation

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Changing the Transmitter Operating Frequency

The transmitter frequency can be changed in two ways: either from the frequency screen, or by recalling
a preset channel. This procedure details the use of the Frequency screen.

F r e q 1 1 8 . 0 0 0 M H z

C a n c e l O K

(1) From the Control screen, select

frequency to display the Frequency
screen.

(2) Turn the switch to hi ghlight the digit to

be changed, then press the switch.

(3) Turn the switch until the required digit

is shown, then press the switch.

(4) Repeat until the required frequenc y is

shown, then highlight OK and press the
switch.

(5) Only frequencies that fall betwee n the

band edge settings can be selected.

T6T VHF 100 W Transmitter Page 12 Operation

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To Store and Recall Frequency Channels

Up to 100 frequency channels can be stored in the transmitter.

C h 1 0 0
F r e q 1 2 1 . 5 0 0 M H z
R e c a l l
B a c k E x i t

C h 1 0 0
F r e q 1 1 8 . 0 0 0 M H z
S t o r e
B a c k E x i t

C h 1 0 0
F r e q 1 1 8 . 0 0 0 M H z

I n v a l i d f o r M o d e

B a c k E x i t

C h 1 0 0
F r e q 1 1 8 . 0 0 0 M H z
O u t s i d e B a n d E d g e
B a c k E x i t

To store a Channel Frequency:

(1) From the Control screen, select

Channel to display the Channel
screen. Highlight Channel, press the
switch and then turn it until the required
channel number is displayed; press the
switch.

(2) Highlight the MHz frequency value

(see Example 2) press the switch and
then turn it until the required MHz value
is shown. Press the switch.

(3) Highlight the kHz frequency value (see

Example 3), press the swi tch and the n
turn it until the required kHz value is
shown. Press the switch.

(4) Highlight Store and press the switch.

The new frequency is now stored in the
selected channel number.

To recall a Stored Frequency Channel:

(1) From the Control screen, select

Channel to display the Channel
screen.

(2) To make the transmitter operate on

any preset channel frequency,
highlight Channel and press the switch.
Turn the switch until the required
channel number/frequency is
displayed, then press the switch.

(3) Turn the switch to highlight Recall, then

press the switch . Exit the screen. Th e
transmitter now operates on the

recalled channel frequency.
Notes:
If a frequency outs ide the band edge limits is

entered, a message (see Channel Screen ­Example 3) is displayed.

If a frequency not valid for the mode of
operation is entered, a message (see Channel
Screen - Example 4) is displayed.

Channel Screen - Example 1

Channel Screen - Example 2

Channel Screen - Example 3

Channel Screen - Example 4