Park Air Systems B63300HS User Manual
T6T 300 Watt VHF Transmitter
User Documentation
Errata
US
Any errors found in this handbook , or associated equipment h andbooks, are promulga ted
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.]
Handbook Title: T6T 300 Watt VHF Transmitter User Documentation
Handbook Part Number: 31-3T6T300V
Handbook Version: 1.1
Date of Issue: June 2006
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
Page 2
Health & Safety, EN 60950, CAN/CSA-C22.2 No. 60950, UL 60950.
Operation at greater than 200W is subject to FAA approval
Radio IC RSS141, FCC part 15 and 87
.
Declaration of Conformity
We, the undersigned,
Company
Address, City
Country
Phone number
Fax numbe r
certify and decla re under our sole resp onsibility that the following equipment:
Product description / Intended use
EU / EFTA member states intended
for use
Member states with restrictive use None
Manufacturer
Brand
Type
are tested to and conform with the essential requirements for protection of health and the safety of the user and any other person and
Electromagnetic Compatibility, as included in following standards:
Standard Issue date
EN60950-1:2002 2002
EN60215 1989
EN301 489-1, EN301 489-22 06/2005, 11/2003
and is tested to and conforms with the essential radio test suites so that it effectively uses the frequency spectrum allocated to terrestrial/ space
radio communication and orbital resources so to as to avoid harmful interference, as included in following standards:
Standard Issue date
EN 300 676 V1.3.1 03/2003
and therefore complies with the essential requirements and provisions of the Directive 1999/5/EC of the European Parliament and of the
council of March 9, 1999 on Radio equipment and Telecommunications Terminal Equipment and the mutual recognition of their conformity and
with the provisions of Appendix IV (Conformity Assessment procedure referred to in article 10).
The following Notified Body has been consulted in the Conformity Assessment procedure:
Notified Body number
0336 TNO Certification B.V., PO Box 15, 9822 ZG Niekerk, The Netherlands
The technical documentation as required by the Conformity Assessment procedure is kept at the following address:
Company
Address, City
Country
Phone number
Fax numbe r
Park Air Systems Limited
Northfields, Market Deeping, Peterborough PE6 8UE
England
+44 1778 345434
+44 1778 342877
Ground to air communications in the VHF aeronautical band
All countries
Park Air Systems Limited
PAE
T6T HS 300 , T6T HS 200
Name and address
Park Air Systems Limited
Northfields, Market Deeping, Peterborough PE6 8UE
England
+44 1778 345434
+44 1778 342877
TCF/TF reference nr. TCF-124-008
Drawn up in
Northfields, Market Deeping, Peterborough PE6 8UE
Date 10 October 2005
Name and position
A. Horsfield consultant Engineer
Page 4
Health and Safety
T6T 300 Watt VHF Transmitter
The T6T 300 watt VHF transm itter op erates from a low vol tage dc input suppl y, or a st andard m ain s ac
input supply. When using a mains supply, dangerous voltages are present on the rear panel ac connector
and within the equipment. For this reason, only suitably qualified personnel should install and maintain
the equipment.
Antenna Radiation WARNING
In use, an antenna is connected to the transmitter. During installation, consideration must be
given regarding the resultant field strength in areas accessible to personnel. The formula to
determine the field strength is given in the Installation topic.
Beryllium Hazard WARNING
The output transistors used in the power amplifier (PA) of this transmitter contain the toxic
material beryllium. Beryllium oxide dust is toxic if inhaled.
Although no procedures in this documentation instruct component removal, users should be
aware that there could be a hazard if a PA’s output transistors become physically damaged.
Lifting the Transmitter WARNING
The transmitter weighs approximately 79 kg. When lifting a transmitter, especially when
fitting into an equipment cabinet, a minimum of two people should be used. Failure to do so
can result in personal injury.
Disposal
This product is covered by the European Directive 2002/96/EC.
It must not be disposed of in domestic waste.
Disposal should be made using designated collection facilities appointed by the
government or the local authorities in your area.
Page 5
Warnings and Cautions
The following warnings and cautions are used in Park Air documentation.
Warnings
A warning is used t o indicate possible danger to personn el. Throughout Park Air user documentation,
warnings are indicated by the following symbols:
Indicates electrical danger to personnel.WARNING
Indicates a hazardous material.WARNING
Indi ca t es a non-ioniz i ng radia t ion haz ard. WARNING
Indicates a specified danger to personnel. WARNING
Cautions
A caution is used to indicate possible danger to the equipment. Throughout Park Air user documentation,
cautions are indicated by the following symbols:
Indicates the presence of electrostatic sensitive devices (E SDs ). Caution
Indicates a specified danger to the equipment. Caution
Page 6
Customer Support
Contacting Park Air
Customer support is available using email, telephone or fax. If you require help in configuring, installing
or maintaining equipment supplied by Park Air, use any of the contact methods listed below.
Email
Address: support@uk.parkairsystems.com
Telephone
During normal UK office hours: +44 1778 381557
Outside normal UK office hours: +44 7733 124457
Fax
Fax number: +44 1778 381556
Mail
Address: C ustom er Services Departme nt
Park Air Systems
Northfields
Market Deeping
Peterborough PE6 8UE
England
Web Site
Web address: www.parkairsystems.com
Fault Report ing
To ensure that Park Air continues to offer the highest level of after sales service, it is necessary to gather
as much information as possible about equipment faults. If any equipment supplied by Park Air becomes
unserviceable, please complete a copy of the fault report shown on the next pag e, and return it to the
Customer Services department at Park Air.
Page 7
Fault Report
Customer: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Address: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Telephone: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Email: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fax: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment Details
Park Air works order number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment serial number. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Details
Commissioning date. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Failure/repair date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Software version (if known) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Supply voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment environmen t: Office area / dedicated equipment room / heated / air-conditioned
(delete as applicable)
Fault Detail
Symptoms of fault: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Results of any tests: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Any repairs carried out: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comments/action requested: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 8
Abbreviations
The following list gives the standard abbreviations used in Park Air user documentation.
Aampere
ac alternating current
AGC automatic gain control
AM amplitude modulation
ATC air traffic control
BER bit error rate
BIT built- in tes t
C celsius
CAS channel associated signalling
CCE control centre equipment
CD compact disk
CSMA carrier sense multiple access
dB decibel
dBm decibels relative to 1 mW
dc direct current
DSB double sideband
LED light emitting diode
LRU line replaceable unit
mmetre
mA milliamp
MARC multi-access remote control
Mbits/s megabits per second
MHz megahertz
mm millimetre
ms m illisecond
MSK minimum shift keying
mV millivolt
mW milliwatt
PA power amplifier
PC personal computer
PCB printed circuit board
PCU protocol conversion unit
D8PSK differentially encoded 8-phase shift
keying
E1-RIC E1-radio interconnect
E-BIT external bit signal
EMF electromagnetic force
ESD electrostatic sensitive device
ETSI European Telecommunications
Standards Institute
Fig figure
FM frequency modulation
ggramme
HPA h igh power amp lifier
Hz hertz
ICAO international civil aviation
organization
IF intermediate frequency
kbits/s kilobits per second
kg kilogramme
kHz kilohertz
LCD liquid crystal display
pk-pk peak-to-peak
ppm parts per million
PSU power supply unit
PTT press to transmit
PVC polyvin y l ch lo r ide
RCMS remote control and monitoring
system
RF rad io frequency
RSE2 remote site equipment
RSSI radio signal strength indication
SINAD signal plus noise plus distortion to
noise plus distortion ratio
S+N/N signal plus noise to noise ratio
TDMA time division multiple access
TS time slot
UHF u ltra high frequency
µW microwatt
Vvolt
VA vol t-ampere
Page 9
VCCS voice control and communication
switch
VFP virtual front panel
VHF very high frequency
VOGAD voice-operated gain adjusting device
Wwatt
Page 10
Table of Contents
Page
Approvals and Standards 3
Health and Safety 5
Customer Support 7
Abbreviations 9
Overview 15
Purpose 16
Models and Part Numbers 18
Mechanical Installation 18
Operating Parameters 19
Frequency Selection 19
Virtual Front Panel 19
Specification 21
General Specification 22
Variants 22
Number of Channels 22
Frequency Accuracy 22
Power Requirements 22
Dimensions and Weight 23
Transmitter 23
Combiner 23
Environmental 23
AM Modes 24
Transmitter RF Characteristics 24
Output Impedance 24
RF Power Output 24
Duty Cycle 24
Channel Spacing 24
Offset Carrier 24
Harmonic Outputs 24
Spurious Outputs 25
Intermodulation 25
Transmitter Modulation Characteristics 25
Mode 25
Modulation Depth 25
Hum and Noise 25
Frequency Response 25
Distortion 25
Residual FM 26
VOGAD 26
Mute 26
Differential Group Delay 26
Transmitter Control 26
Audio Inputs 26
PTT Time Ou t 26
Page 11
Table of Con t ent s ( continued)
Page
Mode 2 27
RF Power Rise Time 27
RF Power Decay Time 27
Channel Spacing 27
Transmitter Modulation Characteristics 27
Modulation Rate 27
RMS Phase Error 27
Phase Acceleration 27
Transmitter Control 27
Time Out 27
Mode 3 28
RF Power Rise Time 28
RF Power Decay Time 28
Channel Spacing 28
Transmitter Modulation Characteristics 28
Modulation Rate 28
RMS Phase Error 28
Phase Acceleration 28
Transmitter Control 28
Operation 29
Overview 30
T6T VHF Am plifier 31
Rear Panel Supply Switch 32
Drive Assembly 33
Front Panel Controls and Indicators 34
Scroll/Select Switch and LCD 34
Ready Indicator 34
Transmit Indicator 34
Alarm Indicator 34
Standby Indicator 35
Reference Connector 35
Microphone/Diagnostics Connector 35
Rear Panel Supply Switch 36
Setting Up and Operation 37
Normal Operation 37
Using the Scroll/Select Switch 37
Screen Protocol 38
Menu System 38
Menu Lock Screen 40
Control Screen 40
Notes for Setting Up the Transmitter 41
Front Panel Display for 25 kHz and 8.33 kHz Channel Spacing 41
Line Level Setting 42
Offset Carrier Operation 42
Changing the Transmitter’s Operatin g Frequency 43
To Store and Recall Frequency Channels 44
To Store a Channel Frequency: 44
To Recall a Stored Frequency Channel: 44
To Initiate a BIT Test 45
Standby Mode 46
To Enter Standby Mode 46
To Exit Standby Mode 46
Settings 47
AM-Voice Settings Procedure 49
AM-Voice Mode Settings Screen 49
Page 12
Table of Con t ent s ( continued)
Page
AM-MSK Mode Settings Procedure 51
AM-MSK Mode Settings Screen 51
Mode 2 Settings Screen 52
Mode 3 Settings Screen 52
Polarities Screen AM-Voice and AM-MSK 53
AM-Voice and AM-MSK Polarity Settings 53
Mode 2 and Mode 3 Polarity Settings 56
AM-Voice and AM-MSK BIT Screen 57
Mode 2 and Mode 3 BIT Screen 59
Software Configuration Screens 60
Band Edges 61
BIT Status Warning Screens 62
Installation 67
Warnings and Cautions 68
Introduction 69
Fuses and Connectors 70
Installing the Transmitter 71
Initial Inspection of the Transmitter 71
Fitting the Correct ac Input Fuses 71
Fitting the Drive Assembly and Amplifiers into an Equipment Cabinet 72
Connecting the Amplifiers to the Drive Assembly 73
Fitting and Connecting the Combiner 74
Fitting 74
Connecting 75
Connecting the Antenna 75
Connecting the Chassis Stud 77
Connecting the DC Input Supply 77
Connecting the AC Input Supply 78
Configuring the Transmitter for Operational Use 79
Front Panel Connectors 86
Microphone/Diagnostics Connector 86
Reference Connector 86
Rear Panel Connectors 87
MARC Connector 88
MARC Audio Connector 89
MARC Data Connector 91
T1/E1 Connector 92
HDLC Connector 93
External Speaker 94
Facilities Connector 95
Page 13
Table of Con t ent s ( continued)
Page
Maintenance 97
Introduction 98
Configuration 98
Hardware Configuration 98
Software Configuration 99
Replacement Modules 99
Scheduled Maintenance 100
Cleaning and Checking Security of Connectors 100
Setting the Transmitter Internal Reference Frequency 100
Setting a 5-Offset Carrier Frequency 101
To Initiate a BIT Test 102
AC and DC Change-over Check 103
Unscheduled Maintenance 104
Introduction 105
Molex KK Connectors 105
Tools, Materials and Test Equipment Required 105
T6T VHF Amplifier Procedures 106
Top and Bottom Covers 106
Removing and Refitting the Interface Module 106
Removing and Refitting the PSU Regulation Module 108
Removing and Refitting the Power Supply Modules 109
Removing and Refitting the Combiner BIT Module 110
Removing and Refitting the PA Modules 112
Removing and Refitting the Front Panel PCB 114
Removing and Refitting the Cooling Fans 115
T6T VHF Drive Assembly Procedures 116
Removing the Top Cover 116
Removing and Refitting the Processor Module 116
Removing and Refitting the PSU Regulation Module 118
Removing and Refitting the Drive Module 120
Removing the Bottom Cover 121
Removing and Refitting the PA Control Module 121
Removing and Refitting the Power Supply 123
Removing and Refitting the Front Panel PCB 124
Virtual Front Panel (VFP) 126
Installing the VFP Software 127
VFP Features 127
The Menu Bar 127
Settings Window 128
Channels Window 128
BIT Window 128
Status Information Window 128
To Change the Drive Assembly Profile or Save a Profile 129
To Initiate a BIT Test 130
To Calibrate the Transmitter 130
Page 14
Overview
Purpose
The T6T 300 watt VHF 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).
The transmitter, see Fig 1 and Fig 2, consists of a drive assembly, three 100 watt amplifiers and a
combiner. The transmitter is configured as shown in Fig 3. Should any one of th e amplifiers fail, the
transmitter continues to operate at reduced (200 watt) power.
T6T VHF Amplifier
T6T VHF Amplifier
T6T VHF Amplifier
T6T V H F D r ive Assemb ly
Fig 1 T6T 300 Watt VHF Transmitter
T6T 300 Watt VHF Transmitter Page 16 Overview
Fig 2 T6T VHF Combine r
100 W Amplifier
Drive Ass embly
100 W Amplifier
Combiner
100 W Amplifier
Fig 3 300 Watt Transmitter Arrangement
T6T 300 Watt VHF Transmitter Page 17 Overview
Models and Part Number s
Table 1 identifies a T6T 300 watt VHF transmitter.
Fig 4 shows the ident ification labels attache d to each com ponent. Eac h label identifies the model, part
number, serial number and modification level.
Table 1 Model Identification
Description Part Number Frequency Range Channel
Spacing
Special
Applications
(AM-Voice)
T6T 300 watt standard frequency
coverage, high stability, VHF
B63300HS 118 to 136.975 MHz 25 kHz or
8.33 kHz
Supports 5- offset
carrie r op e r at io n
transmitter
PAE
Model:
Part No:
S / No:
Mod Record:
Drive Assembly Identification Label Amplifier Identification Label Combiner Identification Label
T6T VHF Drive Assembly
24-06633001/3
2L0001
X 6 7 8 9 10 11 12 13
Park Air Systems Ltd England
PAE
Model:
Part No:
S / No:
Mod Record:
T6T VHF Amplifier
24-31633001/2
2L0001
X 6 7 8 9 10 11 12 13
Park Air Systems Ltd England
PAE
Model:
Part No:
S / No:
Mod Record:
T6T VHF Combiner
24-33633001/2
2L0001
1 2 3 4 5 6 7 8 9 10
Park Air Systems Ltd England
Fig 4 Identification Label Examples
Mechanical Installation
The transmitter, as shown in Fig 1, fits into an industrial standard 19 inch (483 mm ) equipment cabinet
and occupies, in total, 14U of cabinet space. Additionally, the combiner must be mounted at the back of
the equipment cabinet directly behind the amplifiers’ cooling fans. A bracket provided (shown fitted in
Fig 2) is used to mount the combiner on a cabinet upright.
T6T 300 Watt VHF Transmitter Page 18 Overview
Operating Parameters
The transmitter’s operating parameters are set using the drive assembly’s multi-purpose Sc roll/Select
switch, or remotely from suitable control equipment. Addition ally, the Park A ir Virtual Front Panel (VFP )
software can be used to set up the transmitter.
Frequency Selection
The transmitter is a single frequency synthesised radio th at can operate with 25 kHz and 8.33 kHz
channel spacing. The radio recognizes frequencies entered in ICAO format and automatically adjusts to
the correct channel spac ing. For multichannel operation up to 100 pres et frequency channels can be
stored in the ra dio for immedi ate recall; any combination of 8.33 kHz a nd 25 kHz channel spa cing can
be stored. Valid operating frequencies can be selected from the radio’s front panel or a compatible
remote control equipment.
Virtual Front Panel
The VFP software supplied on CD with the radio is compatible with any PC or laptop running Windows
2000™ or W indows XP™. The VFP allows change s to a radio’s settings and channel informa tion, 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 5. Using the VFP has several
advantages over setting a radio from the front panel; these are:
❑ A profile of the operational settings and chan nel i nformation can be created, s tore d on disk , and
then recalled to download into other radios
❑ A printout 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 5 Typical VFP Presentation
T6T 300 Watt VHF Transmitter Page 19 Overview
Intentio n ally Blank
Specification
General Specification
The general specification applies to the transmitter irrespective of the selected operating mode.
Variants
Only one variant of the T6T 300 watt transmitter is available as detailed in Table 2.
Table 2 300 Watt T6T Transmitter
Description Part Number Frequency Range Special Applic ati ons
300 watt, standa rd frequency coverage,
high stabilit y, VHF trans mitter
B63300HS 118 to 136. 975MHz Supports 5-off set carrier
operation
Number of Channels
The transmitter has a multichannel capability. 100 channels can be stored and recalled .
Frequency Accuracy
The frequency accuracy is better than 0.3 ppm.
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 3.
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 3.
Table 3 Power Consumption
Requirement
Maximum 3000 VA 75 A
Typical 2100 VA 60 A
Not Transmit ti ng 350 VA 3.5 A
T6T 300 Watt VHF Transmitter Page 22 Specification
Normal Operation
ac dc
Dimensions and Weight
The transmitter consists of one drive assembly, three amplifiers and a combiner.
Transmitter
The dimensions and wei ghts qu oted below are for a c om plete trans mitter (that is a drive assem bly pl us
three amplifiers):
Width 483 mm (19 inches).
Height 622.3 mm (24.5 inches). The height occupies 14U 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 79 kg (174 pounds).
Combiner
The dimensions of the combiner, including connectors, are:
Width 205 mm (8 inches).
Height 180 mm (7 inches).
Depth 85 mm (3.4 inches).
Weight 1 kg (2.2 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 six integral fans that normally run 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 op erational within 20 seconds but can t ake up
to 10 minutes to achieve frequency accuracy for offset carrier.
T6T 300 Watt VHF Transmitter Page 23 Specification
AM Modes
The transmitter can operate in AM-Voice mode (st andard) and A M -MSK mo de (opt ional). The following
specifications apply to both modes unless stated otherwise. ETSI test methods specified in EN 300 676
are used where applicable.
Transmitter RF Characteristics
Output Impedance
50 ohm via an N-type connector.
RF Power Outpu t
The RF carrier output power is adjustable in 6 W steps from 30 W to 300 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 -0.5 to +1 dB over the operational
frequency range.
Low supply voltage Variations in power remain within ±1 dB for supply voltages between
27 Vdc and 32 Vdc. For voltages less than 27 Vdc the power
progressively reduces b y up to 3 dB. When the minimum dc v oltage
level is reached, the transmitter dekeys.
High VSWR L oop error can reduce po wer progressively by up to 3 dB. Varia tions
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 temperat ure sensor exceeds 80°C the output powe r 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.
Amplifier failure If one of the three amplifiers fails, the transmitter continues to operate
at 66% of the original set power.
Rise time The power rise time from a keying contact to 90% of full power is less
than 50 ms.
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-offset carrier.
AM-MSK mode Offset carrier is not available.
Harmonic Outputs
All harmonic outputs are less than -80 dBc.
T6T 300 Watt VHF Transmitter Page 24 Specification
Loading...