Axcera | Visionary - High Power IOT Transmitters, Depressed Collector MSDC IOT Transmitters

Whether your requirement is a single or multi-collector IOT, air, water or water/glycol cooling, digital or analog, the Visionary Series transmitter is your high power UHF solution for today and tomorrow. By accommodating multiple tube styles from various manufacturers all in the same transmitter design, the Visionary DT ensures that the power amplifier will be supported for the life of the transmitter, as it can even be converted from one technology to another in the field.

The Visionary Series is already the most full-featured and best-engineered line of IOT transmitters available, and the addition of analog and digital high efficiency multi-collector amplifiers, with the flexibility to choose the technology and tube vendor, takes it another step beyond other transmitter offerings.

With every standard analog configuration comes a dedicated upconverter and broadband LDMOS driver amplifier for each IOT final amplifier. This design provides independent correction for each tube, optimizing performance while providing excellent redundancy and ensuring on-air reliability. For the ultimate in digital output performance, the Axciter and companion upconverter replace the analog exciter configuration, offering the advantage of continuous linear and non-linear adaptive pre-correction.

Dual modulators or exciter/drivers with automatic switchover are also available to suit the highest redundancy requirements. Available precise frequency control, which is especially critical in adjacent channel applications, allows the exciter to be locked to any precision 10MHz standard for a ±2Hz frequency stability. Control and monitoring is provided through Axcera's Advanced Control System (ACS™), designed to provide straightforward control and monitoring functionality for the complete transmitter system, both locally and remotely.

Like all Axcera products, every Visionary and Visionary DT transmitter is backed by our world-class customer service organization. This ensures the highest level of product support available, and protects your investment into the future.

For analog broadcasting, Visionary transmitters combine nearly 20 years of Axcera RF design experience with proven IOT amplifier technology, resulting in a world class transmitter system.

Designed to meet the needs of the most demanding full service broadcasters, this product line is available in many configurations. Single tube air-cooled units provide up to 30 kW peak visual power, while multi-tube air-cooled designs are available up to 120 kW. If your preference is liquid cooling, power levels to 70 kW can be achieved with a single tube, while multi-tube configurations provide up to 420 kW. Additionally, our versatile design ensures that conversion of the Visionary to digital operation is very straightforward and cost effective, protecting your investment into the future.

The Visionary DT benefits from Axcera's extensive digital broadcasting experience. Exceptional performance is ensured with highly stable and low noise carrier generation, along with precise digital filtering. Like the analog version, this unit is available in many configurations. Single tube air-cooled transmitters are available up to 12.5 kW average power with multi-tube air-cooled units available to 50 kW. Choose liquid cooling and a single tube can provide up to 30 kW average power, while 180 kW can be achieved in multi-tube configurations. Because it was designed for operation in the U.S. and abroad, the Visionary DT is available in either 8VSB or COFDM configurations, and can be easily converted between the two.

For digital operation, Visionary DT transmitters include the new Axciter digital television modulator, the most advanced ATSC exciter available today. Building on the field proven hardware platform of Axcera's digital exciter family, the Axciter offers terrestrial broadcasters the most flexible solution available. Because it operates using 100% digital signal processing, the Axciter can evolve as broadcast requirements change, helping to protect your investment for many years to come.

This unit utilizes a patented VSB modulation technique which makes it possible to generate a virtually perfect 8VSB IF signal. Since the Axciter is a completely reprogrammable digital television exciter, it can be easily upgraded in the field with new software versions through the convenient front panel USB port. Critical parameters can conveniently be set and queried directly on the color LCD screen or through an interface to a personal computer.

The DSP circuitry also handles frequency offsets allowing an unlimited number of user selectable offsets. In addition, asynchronous resampling techniques compensate for errors in the SMPTE-310M input sample rate, ensuring the best possible signal generation.

The companion upconverter accepts the standard 44 MHz IF output of the digital VSB modulator and produces on-carrier RF for any TV channel. The upconverter, which is based on proven frequency-agile dual-conversion technology using low noise PLL sources, requires no fixed channel filter in its signal path. This allows any channel to be selected directly from the front panel display with no tuning or hardware changes required, enabling a single broadband transmitter to back up multiple channels. This also simplifies spare parts stock as the hardware is the same for all channels.

Both the upconverter and the 8VSB modulator can be locked to an external 10 MHz reference for synchonization or precise frequency offset control. Non-volatile operation is achieved through flash-RAM, which instantaneously stores all digital settings for the entire exciter-modulator system. this ensures that, in case of power loss, the system will return to the previously selected settings when power is restored, saving time by eliminating the need to re-enter operating parameters.

For DVB-T and DVB-H applications, the Visionary DT is available with Axcera's DVB-compliant DVB1A-R COFDM modulator. This unit offers digital linear and non-linear pre-correction for a high quality output signal. Other available features include DVB-H and SFN modes, hierarchical modulation and more. As with ATSC operation, the modulator feeds the Axcera digital upconverter for excellent performance.

For analog broadcasting, Visionary transmitters offer a precision Axcera exciter/modulator using combined visual/aural processing. Drawing on the experience of hundreds of Axcera exciter retrofit systems in television stations everywhere, this exciter has unequaled stability, performance, and signal corection capability. Differential phase correction is achieved in the modulator stage while the upconverter section provides the necessary signal correction for linearity, ICPM and frequency response distortions. Multi-tube configurations include dedicated upconverters, providing independent correction for each final amplifier, optimizing performance and providing excellent redundancy.

The extensive correction capability of the exciter, along with the excellent performance of out LDMOS driver amplifiers, provides intermodulation performance better than 60dB below visual carrier. Stability is also enhanced with an automatic level maintaining consistent performance over environmental variations.

Every Visionary Series transmitter uses broadband solid state LDMOS driver amplifiers, yielding exceptional performance with low power consumption. The advanced design provides high efficiency and excellent linearity performance, minimizing in-band beat products and simplifying out-of-band filtering. These amplifiers are fully broadband across the entire UHF band, minimizing spare parts stock for multi-station operators, and simplifying channel changes.

The amplifiers are housed in slide-out modules with hinged front panels, providing convenient access for easy amplifier maintenance. An independent power supply, cooling system, circulator and protection circuitry are integral to each amplifier tray. Additionally, status LEDs and metering are prominently located on the front panel for simple monitoring of critical operating parameters.

Visionary Series transmitters are designed to accept single or multi-collector IOTs, air, water or water/glycol cooling, and multiple sources of IOTs and circuit assemblies for both analog and digital service. This gives the users the flexibility to choose the technology and the security that the power amplifier will be supported for years to come.

The Visionary Series IOT final amplifier is easily accessed through the front of the transmitter. The roomy cabinet interior was designed for convenient component access and all wiring is dressed in conduit for long-term reliability. A low level output coax breakaway is included to further ease tube maintenance while protecting the output cavity during tube removal and replacement. Designed to IEC-215 safety standards, all high voltage components associated with the IOT are located in a separate compartment within the final amplifier cabinet. Access to the separate high voltage compartment is obtained only through a key interlock system.

Standard on all Visionary DT transmitters, our exclusive Axcera Adaptive Correction Technology (AXACT) provides dynamic digital pre-correction which automatically tracks and corrects for distortions, both linear and non-linear, in the complete transmitter system. All adaptive operations are performed in the high-speed processor, which is capable of equalizing a complete transmitter system in just sixty seconds, and completing a full system optimization in about two minutes.

The continuous, real-time, non-linear component of AXACT is by far the most critical element of the correction system. Since the majority of linear distortions are caused by factors external to the transmission system, ATSC set-top boxes are designed to correct for large amounts of linear distortions. However, since DTV recievers cannot correct for non-linear distortions, this must be handled in the transmitter system or coverage will be affected in the fringe areas.

To obtain the necessary data, AXACT continuously samples the transmitter system output, both before and after the mask filter, through a downconverter integral to the upconverter tray. The modulator processes the data and the necessary digital pre-correction is applied to the modulator output signal, resulting in consistent transmitter system performance, independent of environmental changes.

The Axciter also performs over fifteen safety tests upon each adaptive correction run to confirm that the new correction values are appropriate before applying them to the on-air signal. This ensures that the signal will not be negatively affected by a failure of an RF component in the sample path, such as an RF coupler, connector, relay or cable.

Available on Visionary DT transmitters is Axcera's exclusive DTVision digital signal analysis and test system. Designed to replace expensive DTV test equipment at a fraction of the price, this system samples the transmitter output, measures critical transmitter performance parameters. The information is then displayed in high-resolution graphical format on the modulator's full VGA front panel display - no external PC is required.

Available performance parameters include digital SNR, error vector magnitude (EVM), eye diagram, graphs of adaptive equalizer performance and RF spectrum, constellation diagram, and more.

Every Visionary and Visionary DT includes Axcera's Advanced Control System (ACS). ACS is a user-friendly, full-featured system controller with an intuitive, straightforward graphical user interface (GUI).

The GUI is accessed through a transmitter mounted flat panel color display or an Ethernet connection to a local PC. Control is also available remotely through an Ethernet connection or standard telephone line (POTS), offering all of the functionality of the local screen

ACS provides access to all system control and monitoring through soft-keys and nested block diagrams with "drill-down" capability. Simply select the desired control or monitoring function on the full-color touch screen LCD panel, and ACS clearly displays the requested information in both graphical and text formats, with no distracting 3D graphics. Integral to the system is a fault logging feature which records critical system parameters at user selectable intervals and stores all fault events for system evaluation.

In addition to ACS, each PA cabinet includes separate front panel analog meters, which provide a quick read on critical IOT parameters, along with numerous status indicators and a digital LCD text display, providing a comprehensive view of other important parameters. Distributed control of multiple amplifiers provides independent operation for maximum reliability.

For added reliability, microprocessor control can be bypassed for emergency operation, without losing critical metering and protection functionality.

Analog Power	30-480 kW
Digital Power	12.5-180 kW

Axciter Digital Exciter-Modulator
Axcera is the industry leader in ATSC exciter technology. The Axciter operates using 100% digital signal processing allowing it to evolve as broadcast requirements change.

DC IOTs
Visionary Transmitters are designed to accept single or multi-collector IOTs helping you keep your energy costs down.

Upgradable to Digital
Transmitter parts are interoperable whether analog or digital, helping to eliminate spare parts stock. Analog transmitters are also upgradeable to digital with minimal changes required.

Eliminate Obstacles
Broadband driver amplifiers minimize spare parts stock and add simplicity for stations planning on moving DTV channels to current analog frequencies.