MFJ-991B IntelliTuner Automatic Antenna Tuner Instruction Manual
2005-2012 MFJ Enterprises, Inc.
2
The MFJ-991B tuner enters a “sleep” mode when idle and when no transmit signal is present, turning off
the microprocessor clock to avoid the generation of spurious signals.
Features
• Automatically matches antennas with impedances of 6 to 1600 ohms or 6 to 3200 ohms
• Handles 300 watts (match 6 to 1600 ohms) or 150 watts (match 6 to 3200 ohms)
• Tunes in less than 15 seconds, usually less than 5 seconds
• Over 10,000 non-volatile memories for tuner settings
• Four memory banks with over 2500 memories per bank
• Highly efficient switching L-network matching circuit
• 1.8 to 30 MHz continuous frequency coverage
• Selectable target SWR 1.5 or 2.0 (default is 1.5)
• Selectable SWR threshold 0.5, 1.0 or 1.5 (default is 0.5 above target SWR)
• Lighted cross-needle SWR/wattmeter with high, low and auto range options
• Built-in frequency counter for remembering frequency-specific matching values
• SO-239 coax fed antenna connector
• Connector for random wire or single wire antennas
• Optional remote control
• Optional radio interface cables for compatible radios
Specifications
• Impedance matching range : 6 to 1600 ohms (300 watts) or 6 to 3200 ohms (150 watts)
• SWR matching range : Up to 8:1 for < 50 ohms and up to 32:1 for >50 ohms (300 watts)
Up to 8:1 for < 50 ohms and up to 64:1 for >50 ohms (150 watts)
• Minimum power for tuning : 2 watts (optimum SWR tuning accuracy occurs at 10-20 watts)
• Maximum power while tuning : 100 watts with foldback, 20 watts without foldback
• RF power limit : 300 watts SSB/CW
• Frequency range : 1.8 to 30 MHz continuous coverage
•
Frequency counter accuracy : ±1 kHz across HF bands
• Capacitance range : 0 to 3900 pF (256 values)
• Inductance range : 0 to 24 μH (256 values)
• Relay rating : 16 amp 1000 volts
• Relay electrical life : 100,000 operations
• Relay mechanical life : 10 million operations
• Memory endurance : 1 million write cycles
• Memory data retention : > 200 years
• Power supply requirements : 12 - 15 volts DC
• Current consumption : 850 mA or less
• Dimensions (connectors not incl.) : 10.1 × 2.8 × 9.2 in; 257 × 71 × 234 mm (w × h × d)
• Weight : Approx. 3.7 lb; 1.68 kg
† Specifications and design are subject to change without notice.