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NX Advanced User Interface (AUI)
The NX25 features a 17 inch color LCD screen with a wide range of configurable displays. The AUI can be controlled by touch screen, or via a mouse and keyboard.
Some of the features of the AUI include:
Real-time Impedance locus measurement
Instrument grade spectrum analyzer
IBOC modulation analyzer
Module level monitoring and control
Logging of all functions
Screens are easy to set up and read, and clearly display the parameters you need to see.
100% Remote Access
No matter where you are, youre only moments away from ensuring your NX25 transmitter is operating optimally. Pull up a web browser, enter your transmitters IP address, and youre connected. The complete local NX25 display functionality is available via the internet. Users can access status, controls, alarms, logs and reports.
Control Redundancy
The touch screen interface is implemented as a non-critical functional unit and may be completely removed from the system without affecting transmitter operation.The NX25 also supports SNMP and traditional direct wired contact closure capability for local or remote control.
Real-Time Impedance Measurement
The NX25 uses Nautels patent-pending real-time impedance measurement technology which compares the transmitted voltage and current waveforms to measure the load impedance over the operational frequency range. Because this system can measure impedance without requiring artificial swept tones, the antenna system impedance locus can be measured without taking the station off-air. Impedance is measured at the combiner so no correction for harmonic filter phase is required. This capability allows the antenna system load impedance can be optimized and monitored while the transmitter is operating normally.The NX25 also includes a built in directional coupler for spectrum measurement.Traditionally transmitters have utilized a voltage or current sensor. The directional coupler increases the accuracy of spectrum measurement into a real antenna load which is quite important when measuring adjacent channel emissions.
Class Leading Space Efficiency:
The NX25 is smaller than any other transmitter in its class. Yet even with such a compact footprint the NX25 offers easy and spacious access to all major serviceable components and modules.
On-Air Serviceability
NX25 transmitters are ruggedly engineered to provide easy on-air service and maintenance. In the NX25, 10 amplifiers combine to deliver up to 37.5 kW of average power (carrier plus modulation). At all power and modulation levels, all modules contribute equally to the final output. If an amplifier fails, no stress is imposed on the remaining modules and spectral integrity is
never compromised. Maintenance can be performed whenever it is convenient. Generous ventilation is provided by redundant brushless DC ball bearing fans mounted in removable trays below the power modules. Airflow is unaffected by AC supply variations, further ensuring cool operation and long term reliability.
Automatic Standby
The most critical part of a transmitter is the exciter section, which provides the RF carrier and modulation control signals to the
power modules. A unique feature of Nautel transmitters is the complete duplication of these circuits. Should a failure occur in the RF drive or modulator drive, the transmitter automatically switches over to the built-in standby exciter. This dramatically enhances the already high operational reliability inherent in the modular solid-state design.
Unattended Operation
The NX25 transmitter is built to stay on the air without human supervision. The NX25 was designed with a high VSWR threshold of 1.5:1 at rated power with 100% modulation. With more extreme VSWR values, power is automatically reduced to a safe level. A unique circuit also dynamically stabilizes power against AC line voltage variations. After an AC power loss, over voltage or RF overload, prior operating status is automatically restored.
Powerful Building Blocks
The building block of the NX25 is an integrated RF amplifier/modulator with a carrier power capability of 2500W. These power modules plug into the front of the transmitter, making service easy. The Class-D RF amplifier uses four transistors that can be replaced without soldering using only a screw driver. Due to advances in amplifier technology, this amplifier is so efficient (96%) that it is capable of operating at over 10kW continuously. This power capability results in very low transistor junction temperatures assuring reliable operation even in the highest ambient temperatures.
Redundant Architecture
Redundancy features and protection systems help you maintain operation without a site engineer, reducing your operating costs even further.
The NX25 offers:
Redundant Exciters
Redundant Modulators
Parallel/redundant fans
Redundant low voltage power supplies
Redundant amplifier control power supplies
Failsafe manual and remote control
Technical Specifications:
27.5 kW RF maximum output power
90% efficiency at 25 kW typical
140% positive peak modulation at 25 kW
1.5:1 VSWR threshold at 25 kW, 100% modulation
Frequency Agile
10 RF power modules each with:
Digital optimized linear design
Integrated RF amplifier/modulator
Microcontroller for protection and monitoring
Short circuit protection
Hot pluggable Dual exciters
AM precorrection
2.7 mega-samples/second Direct Digital Modulation
Dynamic carrier control system included
Integrated AM stereo
Audio filtering with pre-emphasis and low pass
Automatic changeover
Integral Digital Broadcast Support options
HD-Radio
Two AES-EBU inputs supporting analog or digital I,Q inputs
DRM 4.5/5/9/10/18/20 kHz and simulcast modes
DRM SFN Support
Control and Monitoring
17/436mm LCD touch screen
Web based remote access/control
SNMP and contact closure remote
Redundant back-up control interface
Module level monitoring
Power, current, voltage, RF spectrum, RF impedance, Modulation, heat sink, fan RPM
Voltage: 350-510 Vac 3 phase @ 50/60Hz or to customer specifications
NX25 Dimensions
1.84 m H x 0.96 m W x 1.12 m D
72.5 H x 37.75 W x 44 D
Weight: 505kg/ 1110lbs
Note: Specifications are subject to change without notice
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