Gigawave US RFXENG2029 User Manual
RACK MOUNT TRANSMITTER (RFX-RMT)
OPERATORS MANUAL
Copyright 2005 RF Central
RFX-RMT Issue 1.1 Page 1 of 38
CONTENTS
1 GENERAL SAFETY INFORMATION............................................................................3
1.1 Health and Safety......................................................................................................4
1.2 Maximum RF Power Density Limits ..........................................................................5
1.3 Issue Status ..............................................................................................................5
2 INTRODUCTION ..........................................................................................................6
3 SPECIFICATIONS........................................................................................................7
4 OVERVIEW OF RFX-RMT TRANSMITTER.................................................................8
5 FRONT PANEL CONTROLS......................................................................................10
6 REAR PANEL CONNECTIONS .................................................................................11
6.1.1a Video for digital transmit section (BNC connectors)......................................11
6.1.1b Video for Analog transmit section (BNC connector)......................................11
6.1.2 Analog audio for Digital Transmit section (XLR connectors).........................11
6.1.3 Digital audio for Digital Transmit section (XLR connectors)..........................12
6.1.4 Analog audio for Analog Transmit section (XLR connectors) .......................12
6.1.5 Power Connector ..........................................................................................12
6.1.6 RF O/P..........................................................................................................12
6.1.7 User Data .....................................................................................................13
6.1.8 Remote Monitoring and Control....................................................................13
7 CIRCUIT DESCRIPTIONS .........................................................................................14
7.1 Audio / Video Encoder ............................................................................................14
7.2 COFDM Modulator ..................................................................................................16
7.3 Analog Transmitter Module .....................................................................................16
7.4 Power Amplifier .......................................................................................................21
8 CONFIGURING THE TRANSMITTER........................................................................22
8.1 Status Monitoring ....................................................................................................22
8.2 Top Level Menu ......................................................................................................22
8.3 Operational menu - MPEG2 mode..........................................................................23
8.4 Engineering Menu – MPEG2 mode.........................................................................24
8.5 Operational Menu – ASI mode................................................................................25
8.6 Engineering Menu – ASI mode ...............................................................................26
8.7 Operational Menu – Analog mode...........................................................................27
8.8 Engineering Menu – Analog mode..........................................................................27
9 PREPARING FOR OPERATION................................................................................34
10 System Remote Monitoring and Setup .......................................................................36
Appendix A - RFX-RMT MPEG Encoder Parameter Sets..................................................37
Appendix B - Table of non-hierarchical bit rates ................................................................38
The information contained in this manual remains the property of RF Central and may not be used; disclosed or
reproduced in any other form whatsoever without the prior written permission of RF Central.
RF Central reserves the right to alter the equipment and specification appertaining to the equipment described in this
manual without notification.
RFX-RMT Issue 1.1 Page 2 of 38
1. GENERAL SAFETY INFORMATION
The information that follows, together with local site regulations, should be studied
by personnel concerned with the operation or maintenance of the equipment, to
ensure awareness of potential hazards.
WARNING- RF Power Hazard: High levels of RF power are present in the unit. Exposure
to RF or microwave power can cause burns and may be harmful to health.
Switch off supplies before removing covers or disconnecting any RF cables, and before
inspecting damaged cables or antennas.
Avoid standing in front of high gain antennas (such as a dish) and never look into the open
end of a waveguide or cable where RF power may be present.
Users are strongly recommended to return any equipment that requires RF servicing to RF
Central.
WARNING- GaAs / BeO Hazard: Certain components inside the equipment contain
Gallium Arsenide and Beryllium Oxide that are toxic substances. Whilst safe to handle
under normal circumstances, individual components must not be cut, broken apart,
incinerated or chemically processed. In the case of Beryllium Oxide, a white ceramic
material, the principal hazard is from the dust or fumes which are carcinogenic if ingested,
inhaled or entering damaged skin.
Please consult your local authority before disposing of these components.
CAUTION- Tantalum Capacitors: When subjected to reverse or excess forward voltage,
ripple current or temperature these components may rupture and could potentially cause
personal injury.
CAUTION: This system contains MOS devices. Electro-Static Discharge (ESD)
precautions should be employed to prevent accidental damage.
RFX-RMT Issue 1.1 Page 3 of 38
1.1 Health & Safety
Exposure to Non-Ionizing (RF) Radiation/Safe Working Distances
The safe working distance from a transmitting antenna may be calculated from the
relationship:
PT. GR
D =
√
In which D = safe working distance (meters)
PT = transmitter or combiner power output (watts)
GR = antenna gain ratio = anti log (gain dBi ÷10)
w = power density (watts/square meter)
The RF power density value is determined by reference to safety guidelines for exposure
of the human body to non-ionizing radiation. It is important to note that the guidelines
adopted differ throughout the world and are from time-to-time re-issued with revised
guidelines. For RF Central use, a maximum power density limit of 1w/m² is to be applied
when calculating minimum safe working distances.
Important Note: It must be remembered that any transmitting equipment radiating power
at frequencies of 100 kHz and higher, has the potential to produce thermal and athermal
effects upon the human body.
To be safe:
a) Operators should not stand or walk in front of any antenna, nor should they allow
b) Operators should not operate any RF transmitter or power amplifier with any of its
Worked examples
Antenna Transmitter Power
Type Gain (dBi) Gain Ratio 2W 4W 10W 30W
OMNI
HELIX
PARABOLIC
DISH
4π.w
anyone else to do so.
covers removed, nor should they allow anyone else to do so.
4 2.5 1 1 1.5 2.5
20 100 4 5.6 9 15.5
35 3,162 22.5 32 50 87
MINIMUM SAFE DISTANCE (METERS)
RFX-RMT Issue 1.1 Page 4 of 38
1.2 Maximum RF Power Density Limits
The RF Radiation Power Density limit figure recommended by RF Central is based upon
guideline levels published in:
a. IEEE standard C95.1 1999 - IEEE Standard for Safety Levels with respect to
Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz.
b. Guidelines for Limiting Exposure to Time-varying Electric, Magnetic &
Electromagnetic Fields (up to 300 GHz) published in 1998 by the Secretariat of the
International Commission on Non-Ionizing Radiation Protection (ICNIRP).
Both documents define guideline RF power density limits for "Controlled" and
"Uncontrolled" environments. An uncontrolled environment is defined as one in which the
person subjected to the RF radiation may be unaware of and has no control over the
radiation energy received. The uncontrolled environment conditions can arise, even in the
best-regulated operations and for this reason the limits defined for the uncontrolled
environment have been assumed for the RF Central recommended limit.
Documents a) and b) also show the RF power density guidelines to be frequency
dependent. Different power density / frequency characteristics are presented in the two
documents. To avoid complexity and to avoid areas of uncertainty, RF Central
recommends the use of a single power density limit across the frequency range 100 kHz to
300 GHz. The 1w/m² power density limit we recommend satisfies the most stringent of the
guidelines published to date.
Footnote: The IICNIRP document may be freely downloaded from the internet at
www.icnirp.de/documents/emfgdl.pdf (PDF file).
1.3 Issue Status
Issue Date Changes
Issue 1.0 30th September 2005 first issue
Issue 1.1 27th October 2005 second issue – revised menu drawings
RFX-RMT Issue 1.1 Page 5 of 38
2. INTRODUCTION
This manual is to be used in conjunction with the RFX-RMT rack-mount switchable
Analog/digital transmitter. When in digital mode the RFX-RMT offers significant features
including ASI and component video inputs together with 4 audios (Analog, AES digital, or
SDI embedded).
The RFX-RMT transmitter is designed for permanent rack-mounted applications, such as
ENG truck/vehicle or fixed link applications. The unit features a comprehensive range
COFDM modulation formats (QPSK 16QAM, and 64QAM) and the MPEG coding format
may be set directly from the front panel control keys and LCD display.
The transmitter comprises a 19” inch rack mount (2 ‘U’) unit that contains both a digital and
an Analog section, with common power supplies and an RF power amplifier.
The digital section of the transmitter comprises an audio encoder, video encoder and
COFDM modulator. The Analog section comprises an integral FM modulator for one video
channel with two associated audio channels.
The RFX-RMT transmitter is most commonly used with a separate power amplifier for high
power ENG applications.
At the receive site a range of RF Central Analog/digital receivers may be used. For
example the RFX-MVRX is a two box rugged portable systems offering the features of
triax remote. Alternatively, the RFX-RMR switchable Analog/digital rack mounted receiver
may be used. Please consult the separate manual for information detailing the operation of
receivers.
RFX-RMT Issue 1.1 Page 6 of 38
3. SPECIFICATIONS
Frequency Band
Frequency Selection
Transmit Power
Digital Specifications
Modulation
Modulation Modes
Data Rate
Bandwidth
Encoding Options
Latency
Video Input
Audio Input
ASI Data Input
Aux Data Input
Analog Specifications
Modulation
Deviation
Spurious
Bandwidth
Video Input
Audio Input
Audio Sub-carriers
General
Power Requirement
Size
Weight
Environmental
Specifications may alter at the discretion of RF Central or to meet customer specific requirements.
1.97 – 2.50GHz band
As per US BAS allocation (current and future plans)
500mW nominal
COFDM DVB-T 2k
QPSK, 16QAM, 64QAM
1
/2 2/3 3/4 5/6 7/
FEC:
Guard interval:
8
1
/32 1/16 1/8 1/
4
4.98 to 31.7 Mbit/s
8MHz (7 & 6MHz options available)
MPEG 2: 4:2:0/4:2:2 high quality video (DVB standard)
Selectable to less than 2 frames minimum, Tx to Rx
Digital: SDI 270Mbit/s
Analog: YUV, Y/C
or Composite (NTSC/PAL)
Digital AES/EBU 2 x stereo
Digital SDI embedded
Analog 2 x stereo / 4 x mono inputs, mic/line selectable
ASI transport stream, 188/204/byte, automatic selection of burst,
byte or packet mode
Aux. RS232 data
FM
Adjustable to current and future BAS channel plans
Better than –60dBm
8MHz (7 & 6MHz options available)
Analog: Composite (NTSC)
Analog: 1 x stereo / 2 x mono inputs, line level
Factory pre-set to 4.83 and 5.80MHz. Programmable +/- 100kHz via
front panel
11-18VDC (Digital mode = 3A at 12VDC, Analog mode = 2A at
12VDC)
19 inch rack mount x 2’U’. Depth = 14 inches
14 lbs.
Temperature: -4° to +122°F
Altitude: 14,500 ft.
Humidity: 95% long term
RFX-RMT Issue 1.1 Page 7 of 38
4. OVERVIEW OF RFX-RMT TRANSMITTER
Motherboard
SHF Power
Amplifier
RF switch
Analog
Transmitter
Module
Modulator
Module
Encoder
Module
Front Panel
Module
The RFX-RMT transmitter comprises seven main modules or assemblies:-
1. Motherboard. This board accommodates the digital encoder and modulator
boards, as well as providing DC, signal and I2C communications routing to/from all
other modules.
2. Encoder module. This module accepts all signals provided for digital transmission
and uses MPEG2 encoding/multiplexing techniques to produce a digital transport
stream for the modulator module
3. Modulator module. This module accepts the digital transport stream from the
encoder module and uses digital COFDM modulation techniques to produce a
digital RF signal and the required RF frequency
4. RF switch. This switch is controlled via the front panel and is used to select either
the RF signal from the digital modulator module or from the Analog transmitter
module.
RFX-RMT Issue 1.1 Page 8 of 38
5. Power Amplifier. This module accepts the Analog or digital RF signal at a level of
–10dBm (nominal) and amplifies the signal to a level of 500mW (+27dBm) nominal.
6. Analog transmitter module. This module accepts an Analog composite video
signal (NTSV) plus up to 2x Analog audio signals (line level) and uses conventional
FM modulation techniques to produce an RF signal complete with audio subcarriers at the required RF frequency.
7. Front panel module. This module contains a microprocessor plus six push buttons
and an LCD display for overall monitoring and control of the RFX-RMT transmitter.
RFX-RMT Issue 1.1 Page 9 of 38
5. FRONT PANEL CONTROLS
Front panel view of the RFX-RMT
The front panel of an RFX-RMT transmitter comprises quantity 2x 2-way switches (On/Off
and Analog/Digital), 1x 10-way rotary switch (BAS channel number), six push button
switches (used to navigate the various RFX-RMT menus) and an LCD display.
Also fitted are three LEDs – ‘DC’ (Green), ‘Status’ (bi-color green/red), and ‘Local’ (bi-color
green and amber)
On/Off Switch Down for Off, up for On
Digital/Analog switch Down= Analog transmission, Up = Digital transmission. Please
note that this function can also be controlled via the push buttons and RFX-RMT menus.
Channel Rotary, 0-10. 1= BAS channel 1, 2 = BAS channel 2, etc to 0 =
BAS channel 10. Please note that the BAS channels can be switched between the
‘current’ plan and the ‘new’ plan via the push buttons and RFX-RMT menus. The exact
frequency selected by either method is shown on the top menu page on the LCD display.
‘DC’ LED Lit green whenever a correct DC voltage is presented to the
RFX-RMT transmitter. This LED will be lit irrespective of whether the unit is switched ‘on’
or ‘off’.
Status LED Stable Green indicates that the RFX-RMT is functioning
correctly. A flashing green light indicates that the RFX-RMT is functioning correctly but that
no video signal is present whilst the unit is switched into ‘digital transmission’ mode. A
stable red light indicates that the unit has an alarm condition.
Local LED Indicates whether the ‘channel’ and ‘Analog/digital’ switching
controls are being accepted from the front panel rocker switches or from the push button
menu. Green light = rocker switch operation, amber light = push button menu operation.
Full details of the push button menu structure can be found in section 8.
RFX-RMT Issue 1.1 Page 10 of 38
6. REAR PANEL CONNECTIONS
Rear Panel view of RFX-RMT showing all connections
6.1.1a Video for Digital Transmit Section (BNC connectors)
Connectors for either SDI digital, composite Analog or component Analog (Y/C or YUV)
video or ASI transport stream. Selected via front panel keypad.
75Ω BNC connectors (female)
6.1.1b Video for Analog Transmit Section (BNC connector)
Connector for composite video input.
75Ω BNC connector (female)
6.1.2 Analog Audio for Digital Transmit Section (XLR connectors)
Line / Mic Hi Z
The four channels of Analog audio are connected via four 3pin XLR Female connectors.
The connectors are designated Ch1, Ch2, Ch3, and Ch4. These inputs can be
independently selected for Line or Mic level inputs with adjustable gain, via the front panel
keypad
Pin
1 Analog Ground
2 Ch1/ A / Left +
3 Ch1/ A / Left -
RFX-RMT Issue 1.1 Page 11 of 38
6.1.3 Digital Audio for Digital Transmit Section (XLR connectors)
The two channels of AES EBU stereo digital audio are connected via two 3pin XLR
Female Connectors. The connectors are designated Ch1 and Ch2.
Pin
1 Ground
2 Hot/ +
3 Return/ -
6.1.4 Analog Audio for Analog Transmit Section (XLR connectors)
Line Level/ 600Ω balanced Z
The two channels of Analog audio are connected via two 3pin XLR Female connectors.
The connectors are designated Ch1 and Ch2.
Pin
1 Analog Ground
2 Ch1/ A / Left +
3 Ch1/ A / Left -
6.1.5 Power Connector
Connector Type: 4 pin XLR connector (male)
Input range: 11 to 18V DC nominal
Pin Function
1 +12VDC
2 Not Used
3 Not Used
4 0V
6.1.6 RF O/P
Connector Type: 50Ω ‘N’ type (female)
RFX-RMT Issue 1.1 Page 12 of 38
6.1.7 User data (future option)
Connector Type: 7 pin LEMO connector EGG.1B.307.CLN
User data selectable as RS485 or RS232
(future option)
RS232 CONNECTIONS RS485 CONNECTIONS
Pin
1 Not Used Not Used
2 Not Used Not Used
3 User Data User Data (-)
4 Not Used Not Used
5 Ground Ground
6 Not Used Not Used
7 Not Used User Data (+)
6.1.8 Remote Monitoring and Control (future option)
Connector Type: 9-way ‘D’ type, female
Remote Control and Monitoring interface selectable as RS485 or RS232
(Future option)
RS232 CONNECTIONS RS485 CONNECTIONS
Pin Direction Direction
1 Not Used Not Used
2 Data Tx Out from Unit Data Tx (-) Out from Unit
3 Data Rx Into Unit Data Rx (-) Into Unit
4 Not Used Not Used
5 Ground Ground
6 Not Used Data Tx (+) Out from Unit
7 Not Used Data Rx (+) Into Unit
8 Not Used Not Used
9 Not Used Not Used
RFX-RMT Issue 1.1 Page 13 of 38
7. CIRCUIT DESCRIPTIONS
RFX-RMT Simplified block diagram
DC in
Power supply
Digital Motherboard
SDI (+ embedded audio), or ASI,
or composite video
YUV, or YC video
AES audio 1, 2
AES audio 3, 4
Analogue audio 1, 2
Analogue audio 3, 4
Composite video
Analogue audio 1
Analogue audio 2
Video/
audio
processing
Power
supply
Video Filter/
Pre-emphasis/
Amplifier
Audio Subcarrier
Modulator 1
Audio Subcarrier
Modulator 2
Encoder
I2S
Video/Audio
Combiner
ASI
MPEG coder
Voltage
Controlled
Oscillator
Transport
stream
I2C Communication Bus
Analogue Module
Buffer
Amp
Power
supply
7.1 Audio / Video Encoder
The Encoder board consists of the following main functions:
• SDI to Digital desterilizer. Converts the SMPTE-259M-C serial digital video input
to an 8-bit parallel digital video bus.
• Analog to Digital Video Converter, 10 bit over sampling ADC
Takes either Composite Video (75 Ω, 1v p-p) (CVBS); YC or YUV inputs in
either PAL / NTSC format, and converts to an 8bit parallel digital video bus.
• FPGA selects the required 8-bit parallel digital video bus from either the SDI or
Analog input, packets this data for input to the MPEG2 encoder. A relay is used
to route the input from the BNC (either SDI or CVBS) to either the SDI
desterilizer or the PAL/NTSC decoder.
COFDM modulator
Front panel display
and push button
RF RF
control
RF
Switch
RF
Power
amplifier
Tx RF Out
RFX-RMT Issue 1.1 Page 14 of 38
• Audio Analog to Digital Converter, 48 kHz, 24 bit. Four high impedance Analog
inputs. The channels are first buffered by a variable gain stage to cater for either
Mic or Line level inputs. A switchable 20dB stage is also included to cater for low
level Mic inputs. The audio channels are then converted into digital signals and
passed to the MPEG2 Encoder.
• Audio SDI de-embedder. Extracts digital audio from the SDI stream
• MPEG2 Encoder. Compresses the video and audio. The encoder uses a suite of
MPEG2 compliant compression techniques, where the data bit rate is reduced
by processing over multiple picture frames. The absolute picture ( Intra frame) is
interleaved with pictures that are created using difference data ( Predicted
frame) with Bi-directionally predicted frames (4:2:2 Only) in conjunction with
motion compensation; thus low data rates down to 4 Mbps, can be achieved.
The encoder includes special modes which are optimized for low delay
(latency).
The encoding parameters are loaded into the encoder at power up. These are
selected from one of the ‘preset’ encoder memories. See 0 and Appendix B
• ASI routing.
As an alternative to the internal MPEG encoder an external ASI data stream
may be used. The ASI input to the front panel is converted to parallel, and
automatically selected for 188/204/byte mode inputs, the signal is then
configured for the modulator input format and routed direct to the transport
stream output, bypassing the MPEG2 coder.
• DC Power Supplies
Switching DC/DC converters are used to generate the various supplies from the
incoming 9-18V battery supply. These include 2.5, 3.3V, 5V, 8V and +/-5V
supplies.
There are no field replaceable parts on the Encoder board. If a fault occurs with the board
contact RF Central for technical assistance.
RFX-RMT Issue 1.1 Page 15 of 38
7.2 COFDM Modulator
The normal scheme of COFDM modulation adopted by RF Central for the RFX-RMT is 2k
carriers with 8MHz RF bandwidth.
The COFDM modulator has been designed to take its input from the MPEG2 encoder, or
from an external ASI. This Transport stream is then modulated directly to the output
frequency band (e.g. 2GHz). This method reduces the occurrence of inter-modulated
harmonic frequencies and requires less up-converters
The COFDM modulator RF output is via the SMB connector. This output is then fed, via
the Analog/digital RF switch, into the power amplifier. The nominal RF output level from
the Modulator is –9dBm.
When the traffic being carried by the Tx is video and audio, the modulator is
automatically configured to match the data rate of the MPEG2 Encoder as defined by
the selected parameter set.
When the traffic being carried by the Tx is ASI, the modulator may be set for
modulation, FEC and guard interval, according to the chart in Appendix B
There are no field replaceable parts on the COFDM modulator. If a fault occurs with the
board please contact RF Central for technical assistance.
7.3 Analog Transmitter Module
The RMTX-0101 Analog transmitter module provides the Analog transmitter function of the
RFX-RMT Digital / Analog transmitter system rack assembly. The board facilitates one
(NTSC) video input and two audio inputs. Operation and frequency selection is via front
panel control. The R.F. output of the board is routed to the RF switch, which selects the
Analog or digital operation mode, and is then amplified to a suitable level for transmission
by the common power amplifier. The RMTX-0101 board is disabled during system digital
operation. On-board bi-color LED’s are provided for R.F. and power supply monitor
functions.
Function.
The functions of the board are:
1. Convert the unbalanced NTSC video input to a frequency (FM) modulated carrier
over a frequency band of 1950 – 2500MHz. A bi-color LED is provided ‘on board’ to
indicate ‘lock’ of the R.F. phase locked loop (PLL) synthesizer. The PLL status is
also reported to the front panel display and can be verified by selecting the
appropriate menu.
RFX-RMT Issue 1.1 Page 16 of 38
2. Convert two balanced line level (+9dBm 600 ohms) audio inputs to frequency
modulated sub-carriers at nominally 4.83 and 5.8MHz. The independent operation
of the two sub carriers is available via front panel control. The sub-carrier
frequencies can be adjusted over a +/- 100 kHz range via front panel control, to
facilitate regional and customer requirements.
Video and R.F output circuit operation.
The
75 ohm unbalanced video input is connected via board mounted SMB socket SK1.
The signal is attenuated and matched by the pin attenuator R1, R2, R3, before low pass
filter FL1. The output of the filter is attenuated by pi attenuator then passed to the preemphasis network consisting of R7-R9, C2-C4, and RV2.
The two audio sub-carriers are summed with the video at this point before video amplifier
IC3. The gain of the stage is adjusted as a function of the R.F. VCO (voltage-controlled
oscillator X1) tuning voltage, to compensate variation in modulation sensitivity across the
1950 – 2500MHz band.
The threshold and gain of the compensation is adjusted by RV3, RV4. These adjust the
voltage at TR1 gate, which varies the drain – source ‘ON’ resistance and hence, since this
forms part of the feedback circuit of IC3, adjusts the gain of the stage to maintain a
constant F.M. deviation. NOTE: RV3 and RV4 SHOULD NOT BE ADJUSTED without
access to the appropriate procedure and test equipment.
The second video amplifier IC4 is arranged with video invert switch S1 so that the F.M.
polarity can be set to be positive (i.e. an increase in R.F. output frequency with positive
going video), or negative (i.e. a decreasing R.F. frequency with positive going video). The
gain of this stage is fixed. The F.M. deviation is set by RV1, which varies the amplitude of
the signal which is A.C. coupled via C39 to the VCO tuning port.
The VCO R.F. output is attenuated by 6dB (R32, R33, R34) and then split by the 50 ohm
6dB splitter R35, R37, R38. One output from the splitter provides a sample frequency to
the phase locked loop synthesizer, (IC6), the other the R.F. output. This is attenuated a
further 10dB (R38, R39, R40) which maintains a ‘good’ 50 ohm match to the R.F. output
and high isolation to the VCO output, which is sensitive to changes. The R.F. is then A.C.
coupled via C29 to the on board SMA socket SK2. The nominal output level is –9dBm.
R.F. phase locked loop and lock detect monitoring
The required transmitter RF frequency output band is achieved by varying the tuning
voltage of VCO (voltage-controlled oscillator) X1. As the tuning volts increases, the RF
output frequency increases. The RF output frequency of the transmitter board is set via the
front panel display and control edit functions.
RFX-RMT Issue 1.1 Page 17 of 38
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