NX 100 Transmitter's Technical Summary:

PAKISTAN BROADCASTING CORPORATION Forums High Power Transmitters Multan HPT NX 100 Transmitter's Technical Summary:

This topic contains 0 replies, has 1 voice, and was last updated by  Ch. Zeshan Yousaf 4 years, 10 months ago.

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    Ch. Zeshan Yousaf

    Transmitter Type:
    Medium Wave, AM, 100% Solid State

    40 RF power modules, each including a single integrated RF amplifier / modulator.
    No frequency dependent parts in Rf module.
    Each module is hot pluggable and has internal micro controller for protection and monitoring over a serial bus.
    Short circuit protection at the module level offers an added layer of protection.
    Dual redundant digital single board exciters utilizing FPGA/DSP technology with automatic changeover.
    Pre-correction utilized specifically to improve digital performance.
    Redundant low voltage power supplies.

    RF Output Power :
    Maximum150 kW RMS
    Peak Power: 552 kW
    Carrier Power Range: 0 to 110 kW
    Up to 62 preset levels, presets may include other operational parameters such as DRM vs Analog and different program inputs
    Output level stabilized against AC supply voltage variations
    Built in Dynamic Carrier Control
    Built in AM stereo

    RF Output Connection
    3 1/8 EIA female standard, other outputs on request
    RF Output Impedance
    50 ohms, unbalanced
    90% typical at 100 kW

    RF Load VSWR
    16,000 peak reflected watts (1.5:1 VSWR @ 100 kW, 100% modulation) results in instantaneous power shutback
    4000 reflected watts RMS (1.5:1 VSWR @ 100 kW, 0% modulation) results in a graceful power reduction

    Frequency Range 531 kHz to 1,620 kHz.
    “Quick frequency change capability”

    Frequency Stability
    ±2 ppm over temperature range
    Optional 300 ppb ovenized source with GPS option

    Modulation Type 6 phase direct digital modulation
    1.8 MHz modulation sample rate

    Modulation Capability
    135% positive peak modulation to 100 kW
    120% positive peak modulation to 110 kW

    Spurious and Harmonic
    Meets ITU-R SM.328-10
    Meets ITU-R SM.329-9

    340 V to 440 V, 3 phase or to customer specifications
    Power Supply Variation ±10% voltage, 47 Hz to 63 Hz
    Power Consumption 111 kW typical at 100 kW, 0% modulation
    167 kW typical at 100 kW, 100% modulation
    Power Factor / Cos (theta)
    0.95 typical

    Temperature Range 0°C to + 50°C
    Derate 3°C per 500 m above sea level (2°C per 1,000 ft)

    Humidity Range
    0% to 95% non-condensing

    Altitude 0 m to 4,000 m (0 ft to 13,000 ft)

    Cooling Air Requirements
    2,550 m3/hr (1,500 CFM)

    Meets EN60215: 1976 Safety Requirements for Radio Transmitting Equipment

    Transmitter Cabinet 184 cm H x 95.7 cm W x 120 cm D (72.4″ H x 37.7″ W x 47.2″ D)
    External Transformer Cabinet 116.8 cm H x 113 cm W x61 cm D (46″ H x 44.5″ W x 24″ D)

    Main transmitter cabinet with modules installed: 567 kg (1250 lbs)
    Power transformer: 753 kg (1659 lbs)

    Analog Broadcast Inputs
    Dual AES-EBU Digital Audio inputs* adjustable from -30dBFS to 0dBFS for 100% modulation

    600 ohms balanced analog audio input +10 dBm nominal for 100% modulation, adjustable from -10 to +12 dBm

    Digital Broadcasting Inputs
    I,Q over AES-EBU, SRC available* with sample rate converter
    I,Q over LVDS, 3 pairs, Clock, Data, frame sync
    *Two AES-EBU inputs provided and may be used for either analog audio or digital I,Q inputs
    Optional Embedded DRM Generator/Content Server
    Optional Embedded HD Radio Generator (Exgine™)

    Frequency Response
    +0.2 dB/-0.8 dB, 30 Hz to 10,000 Hz.
    Optional audio input filters available to meet regional bandwidth restrictions

    Total Harmonic Distortion
    Better than 0.8% (THD), 30 Hz to 10,000 Hz at 95% modulation (typical)

    Intermodulation Distortion
    SMPTE 1:1 Ratio, 60Hz/7kHz, 95% Mod Peak – 0.5% @ 100kW (typical)
    DIM-B, 2.96kHz/9kHz, 80% Mod Peak – 0.5% @ 100kW

    Carrier Shift
    0.5% or less
    Hum and Noise -65 dB or better below 100kW, 100% modulation


    Extensive Control/Monitoring/Troubleshooting system through 17″ front panel LCD touchscreen. Touch panel control system is non-critical and may be removed from the system without affect- ing transmitter operation or remote control/ monitor via direct wired connections. Redundant back-up control interface provides control in case of front panel computer system failure. Built in instrumentation providing detailed spectrum/im- pedance and modulation analysis.

    DC Voltages (B+, PA and 15V)
    DC Current
    Sample Levels (PDM and RF Drive)
    Fan Speeds
    Heat Sink Temperature

    DC Voltage levels (15V, 5V, 30V, 48V and B+)
    Rectifier Fan Speeds
    DC Current
    Rectifier Heat Sink Temperature
    AC Voltage

    Output Current (RMS, Peak, Carrier)
    Output Voltage (RMS, Peak, Carrier)
    Forward Power (RMS, Peak, Carrier)
    Reflected Power (RMS, Peak, Carrier)
    Audio/Modulation Levels (RMS and Peak – Positive/Negative)
    Load Impedance

    PDM and RF Drive Levels Ambient Temp

    RF Monitor
    RF monitor is a power sample (using a directional coupler) that will allow for accurate audio performance measurements

    Easy access to current transmitter operating state, past and present alarm conditions and historical trends of both digital and analog channels

    Schedule Intuitive easy to read built in scheduler
    Up to 144 yearly rules can be defined by user

    Remote Control/ Monitoring
    Three Remote interfaces:
    • Direct wired optically isolated inputs and open collector outputs
    • Web interface – All locally available control is available over TCP/IP web interface • SNMPv1

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