Park Air Systems T6T Operator's manual

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 indicate possible danger to personnel. Throughout Park Air handbooks, warnings
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 sensitive devices
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 the preface, is a hard copy of the files contained on the CD and comprises
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 is intended for use in fixed ground environments 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 into an industrial standard 19 inch (483 mm) equipment cabinet 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 136.975 MHz 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 automatically adjust to the correct channel spacing. For multichannel operation up
to 100 preset frequency channels can be stored in the radio for immediate recall; any combination 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 operating parameters are set using the front panel multi-purpose Scroll/Select 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 Windows XP™. The VFP allows changes to a radio’s settings and channel
information, it displays the current BIT state, displays BIT history, allows security locks to be set, and
provides maintenance facilities. A typical VFP presentation is shown in Fig 2. Using the VFP has several
advantages over setting a radio from the front panel; these are:
❑A profile of the operational settings and channel information can be created, stored on disk, 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 specification applies to the T6T 100 watt transmitter irrespective of the selected operating
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 operates 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 136.975 MHz Supports 5-offset carrier operation
Table 2 Power Consumption
Requirement 100 Watt Transmitter 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 operate in AM-Voice mode (standard) and AM-MSK mode (optional). The following
specifications apply to both modes unless stated otherwise.
Transmitter RF Characteristics
RF Power Output
The RF carrier output power is adjustable in 2 W steps from 10 W to 100 W.As an option, the maximum
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 control characteristics are as follows:
Audio Inputs
Voice can be connected to the transmitter via the front panel microphone connector. Voice can also be
connected via the line inputs. Line level setting from -30 to +10 dBm.
PTT Time Out
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 transmitter specification applicable to Mode 2 operation. Mode 2 parameters are
identical to AM-Voice mode parameters with the following exceptions:
RF Power Rise Time
The transmitter produces more than 90% of full power output within the first 2 symbols of the 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 bits per symbol transmitted as changes in phase rather than
absolute phase. The data stream is divided into groups of 3 consecutive data bits, least significant 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 transmitter specification applicable to Mode 3 operation. Mode 3 parameters are
identical to AM-Voice mode parameters with the following exceptions:
RF Power Rise Time
The transmitter produces more than 90% of full power output within the first 2 symbols of the 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 divided into groups of 3 consecutive data bits, least significant 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.

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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 shows the operating frequency, the channel number (if the
channel store facility is used), the carrier offset (if used), and displays a graphical representation of
instantaneous peak power.
The example LCD screen above shows the transmitter operating on 118.000 MHz; the frequency 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 been detected. BIT indications are
classified as either Alarms or Alerts.
If an ‘alert’ condition is detected, the Alarm indicator flashes, the Ready indicator remains lit, and the
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 condition results in an alarm. When detected, the Alarm indicator lights 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