Nautel AMPFET 50, 50 KW AM Transmitter Specifications

Configuration -48-1.25 kW Power Amplifier/Modulator subsystem modules, (each with integral cooling fan) Main and Standby Exciters with Audio and RF Drivers, Dual Power Supplies

 Power Output -(Rated) 50,000 watts (Capable) 60,000 watts. Three preset power levels between 10,000 and 60,000 watts are selectable via LOCAL or REMOTE control Output level stabilized against ac supply voltage variation

 RF Frequency Range-531 kHz to 1 620 kHz, prefitted to one frequency as ordered

 RF Terminating Impedance-50 ohms unbalanced, 3-1118 inch EIA O/P Flange

 Audio Frequency Response- + 0.5 dB, dc -10,000 Hz Audio input low pass filter selectable between Butterworth and Bessel response

 Square Wave Overshoot-2% or less at 400 Hz (typical with Bessel filter active)

 Square Wave Tilt -3% or less at 40 Hz

Audio Harmonic Distortion-Better than 1% (THD) at 95% modulation 30-    10,000 Hz, 50 kW (Reduced antenna bandwidth may degrade specification)

Audio Intermodulation-1.5% or less at 50 kW 60/7000 Hz 4:1 ratio

Distortion -SMPTE Standards at 85% modulation

AM Stereo (RF Phase Shift)-Incidental Quadrature Modulation (lQM) 35     dB or better below 95% modulation 1 kHz

 Modulation Capability-125% positive peak modulation capability to    55,000 watts

 Carrier Shift- Not exceeding 1%

 RF Harmonics-80 dB or more below 50 kW output

 Spurious Outputs-80 dB or more below 50 kW output

 Noise and Hum (Unweighted)-60 dB or more below 100% modulation at 50    kW

 Frequency Stability- + 5 Hz or + 5 ppm whichever is greater over     temperature range

 Audio Input-600 ohms active balanced + 10 dBm nominal  Adjustable 0 to +12 dBm for 100% modulation

 Power Input-Standard  48OV 60 Hz three phase WYE source

or

 416V 50 Hz three phase WYE source other voltages/source configurations available Separate 120/240V 50/60 Hz single phase supply required for Exciter and Cooling Fans

 Permissible Power

Supply Variation-  + 5% voltage + 5% frequency

Power Consumption-66.7 kW at 50 kW, 0% modulation, 100 kW at 50 kW, 100% continuous sine wave modulation

Power Factor-0.98 typical

Overall Efficiency- Better than 75%

Metering-Forward Output Power, Reflected Output Power, DC Input Current and Voltage to each Power Amplifier Rack

Test Meters, each Exciter

DC Current Meters, each 1.25 kW Power Amplifier/Modulator Subsystem

 Remote Control- Transmitter ON/OFF

Selection of Exciter A or B

Output Power Level selection

Power Trim

 Remote Monitoring - Forward Power Output

Reflected Power Output

Status of Critical Parameters

 Ambient Temperature -10º to 500ºC (derates 3ºC per 500 meters or 2ºC per 1000 feet above sea level)

 Humidity Range -  0-95%

 Altitude - 0-3,000 meters (0-10,000 feet)

Size-4 Power Amplifier Racks and Master Control Rack each 57 x 61 x 183 centimeters (22.5 x 24 x 72 inches)

2 Power Supply and Output Filter Racks each 57 x 76 x 183 centimeters (22.5 x 30 x 72 inches)

 Total floor space 2.6 square meters (28.2 square feet)

 Weight-2270 kilograms (5,000 pounds) approximately