Super-Compact IntelliTuner Automatic Antenna Tuner TM Model MFJ-925 INSTRUCTION MANUAL CAUTION: Read All Instructions Before Operating Equipment MFJ ENTERPRISES, INC. 300 Industrial Park Road Starkville, MS 39759 USA Tel: 662-323-5869 Fax: 662-323-6551 VERSION 1A COPYRIGHT C 2006-2010 MFJ ENTERPRISES, INC.
DISCLAIMER Information in this manual is designed for user purposes only and is not intended to supersede information contained in customer regulations, technical manuals/documents, positional handbooks, or other official publications. The copy of this manual provided to the customer will not be updated to reflect current data.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Contents THE BASICS Introduction...................................................................................................................................... 1 Features............................................................................................................................................ 2 Specifications..................................................................................................
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual APPENDICES Resetting the Tuner ........................................................................................................................ 15 Factory Defaults................................................................................................................ 15 Delete Entire Antenna Memory ........................................................................................
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual FIGURES Figure 1. Typical Installation Block Diagram ................................................................................ 3 Figure 2. MFJ-925 Front Panel....................................................................................................... 4 Figure 3. Button Action .................................................................................................................. 5 Figure 4.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual THIS PAGE IS LEFT BLANK INTENTIONALLY iv © 2006-2010 MFJ Enterprises, Inc.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual The Basics Introduction The MFJ-925 IntelliTunerTM lets you rapidly tune any unbalanced or single-wire antenna automatically. MFJ's exclusive InstantRecallTM, IntelliTuneTM and AdaptiveSearchTM algorithms give you fast automatic tuning with more than 20,000 non-volatile VirtualAntennaTM memories. The antenna has eight banks of memory; with over 2500 non-volatile memories for tuner settings.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Features • • • • • • • • • • • • • Automatically matches antennas from 6 to 1600 ohms impedance (SWR up to 32:1) Handles 200 watts SSB/CW Tunes in less than 15 seconds, usually less than 5 seconds Over 20,000 non-volatile memories for tuner settings Eight memory banks with over 2500 memories per bank Highly efficient switching L-network matching circuit 1.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Fast Start WARNING ● ● ● ● ● Never operate the tuner with its cover removed. Contact with the components inside the tuner while transmitting will result in painful RF burns. Locate the tuner so that the rear terminals are not accessible during operation. The single wire connection may have high voltage while transmitting. Disconnect all antennas from the tuner during lightning storms. Always tune with low power (2-20 watts).
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Front Panel TUNE MFJ IntelliTunerTM ALT POWER SWR TUNE AUTOMATIC ANTENNA TUNER 200 Watts SSB / CW MODEL MFJ-925 Figure 2. MFJ-925 Front Panel. • SWR LED: A green LED that illuminates when the SWR is 1.5 or less. • TUNE LED: A red LED that illuminates when the automatic tuning is in progress. • TUNE Button: Has three different functions based on the length of time you press and hold it before releasing.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Automatic/Semi-Automatic Tuning Mode Pressing [TUNE] and [ALT] simultaneously toggles between automatic and semi-automatic tuning mode. One beep indicates automatic mode and two beeps indicate semi-automatic mode. In automatic mode, the tuning routine is automatically started when at least two watts of power is applied and the SWR is greater than 2.5.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Back Panel POWER 12VDC 750mA MFJ ENTERPRISES, INC. STARKVILLE, MS USA RADIO INTERFACE + TRANSMITTER GROUND ANTENNA Figure 4. MFJ-925 Back Panel. • Power: This jack accepts a standard 2.1 × 5.5 mm coaxial plug with positive center and negative sleeve. The tuner requires 12-15 volts DC at up to 750 mA. The use of a regulated supply is not mandatory but is recommended for best performance. An optional 12 volts DC 1.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Jumper JP2 Jumper JP2, located behind the front panel circuit board, selects the radio to be connected to the Radio Interface connector. Set this jumper to the “I” position to interface with radios that are compatible with the Alinco EDX-2 tuner, Icom AH-3 and AH-4 tuners, Yaesu FT-1000MP series, FT-2000 series, FTDX-9000 series, and any radios that are compatible with Yaesu FH-1 or FH-2 remote control.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual The MFJ-5114I interface cable provides control signals between an Icom radio and the MFJ automatic tuner. Supported Icom radios are IC-706, IC-707, IC-718, IC-725, IC-728, IC-736, IC-738, IC-746, IC-756, IC-7000, and any Icom radio that supports the Icom AH-3 or AH-4 tuner. Push and hold the radio’s [TUNER] button for two seconds to start the tuning process. Push [TUNER] quickly to bypass the tuner.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual 1 Pin 1 (TX INH) connects to pin 7 of Radio Interface Plug. 2 Pin 2 is not connected. Yaesu Rear Panel View 3 Pin 3 (SENSE) connects to pin 5 of Radio Interface Plug. 4 Pin 4 (TX) connects to pin 6 of Radio Interface Plug. 1 2 3 4 5 6 7 8 5 Pin 5 (RX) connects to pin 8 of Radio Interface Plug. 6 Pin 6 (Ground) connects to pin 4 of Radio Interface Plug. 7 Pin 7 is not connected. 8 Pin 8 (+13.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual • Transmitter: SO-239 connector for coax cable from transmitter or transceiver. There is a bias tee connected to this connector so 12 volts DC can be sent down the coax to power the tuner for remote operation. An optional bias tee DC power injector, the MFJ-4116 or MFJ-4117, is available from MFJ Enterprises, Inc. • Ground: Wing-nut terminal for RF ground wire connection.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Miscellaneous Antenna Memory The “memory resolution” is the width of frequency spectrum that the tuner recognizes as being the same as a tuned frequency already in memory. The memory resolution is approximately 0.1 percent of the lower frequency of each amateur band.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Morse Code and Beeps If insufficient power is applied for tuning (less than two watts), “QRO” (dah-dah-di-dah di-dah-dit dahdah-dah) will be sent on CW. Increasing the input power above two watts ends this message. When input power is too high, the tuner enters a self-protection mode. The tuner will not allow any of its relays to change to prevent damage to your tuner.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Grounding Hints To minimize RFI, single wire feedlines (such as used with Windom or longwire antennas) should be kept away from other wiring. Radiation will be minimized if the single wire feeder runs parallel and reasonably close to the wire that connects the tuner to the outdoor ground. The antenna feed wire should be adequately insulated to prevent arcing or accidental contact.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual a half-wavelength. The half-wavelength line repeats the very high antenna impedance at the tuner. Incorrect feedline and antenna lengths can make an otherwise perfect antenna system very difficult or impossible to tune. One example where this problem occurs is on 80 meters when an odd quarter-wave (60 to 70 feet) open wire line is used to feed a half-wave (100 to 140 feet) dipole.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Appendices POWER-ON OPERATIONS (Press and hold buttons while turning on the power.) Press and hold TUNE Press and hold TUNE + Press and hold ALT + POWER then press TUNE 1 time to reset factory defaults. Press and hold ALT + POWER then press TUNE 2 times to delete current memory bank. Press and hold ALT + POWER then press TUNE 3 times to perform total reset.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual To reset the tuner to these defaults: 1. Turn off the power to the tuner. 2. Press and hold only the [ALT] button while turning the power on. Both LEDs will blink until the button is released. 3. Within four seconds of releasing [ALT], press the [TUNE] button once. 4. After releasing [TUNE] for four seconds, beep three times and resume normal operation.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Self Test A self-test routine will check the functions of the MFJ-925. This routine checks the LEDs, the frontpanel buttons, the internal memory, the audio circuitry, and the power-down circuitry. During the selftest, you may stop the test by turning off the unit; however, this should NOT be done during the memory test or the memory could be corrupted. The self-test can be completed in approximately 10 seconds.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Power-Down Circuit Test When the 12 VDC power to the tuner is turned off, the tuner saves all settings to non-volatile memory. The Power-Down Circuit Test checks the power-down detection circuitry. It is recommended that this test be done immediately after the regular self-test described above. Note: The tuner must be reset to factory defaults before performing this test. Here is the test procedure: 1.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Frequency Counter Calibration To calibrate the frequency counter, you will need a transmitter, a 50-ohm dummy load, two 50-ohm SO239 coax cables, a Phillips screwdriver, and a tuning tool or small flat blade screwdriver. WARNING: Do not touch anything inside the tuner during operation! Serious, painful RF burns can result.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual SWR Bridge Calibration To calibrate the SWR Bridge, you will need a transmitter capable of 100 watts output, a precise calibrated wattmeter, a 50-ohm dummy load, three 50-ohm SO-239 coax cables, a Phillips screwdriver, a tuning tool or small flat blade screwdriver, and a cross-needle wattmeter (available only at MFJ factory). Therefore, this calibration can only be done at MFJ factory.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Alinco Radio Interface The MFJ-5114A radio interface allows users of EDX-2 compatible Alinco transceivers to connect to the MFJ-925 IntelliTuner™ Automatic Antenna Tuner. With this interface, control signals are connected between the radio and the tuner. The operator can then control the tuner with a single push of the [TUNE] button on the front panel of the radio.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Icom Radio Interface The MFJ-5114I radio interface allows users of AH-3 or AH-4 compatible Icom transceivers to connect to the MFJ-925 IntelliTuner™ Automatic Antenna Tuner. With this interface, control signals are connected between the radio and the tuner. The operator can then control the tuner with a single push of the [TUNER] button on the front panel of the radio.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Kenwood Radio Interface The MFJ-5114K radio interface allows users of AT-300 compatible Kenwood transceivers to connect to the MFJ-925 IntelliTuner™ Automatic Antenna Tuner. With this interface, control signals are connected between the radio and the tuner. The operator can then control the tuner with a single push of the [AT TUNE] button on the front panel of the radio.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Yaesu Radio Interface/MFJ-5114Y The MFJ-5114Y radio interface allows users of FC-30 compatible Yaesu transceivers to connect to the MFJ-925 IntelliTuner™ Automatic Antenna Tuners. With this interface, control signals are connected between the radio and the tuner. The operator can then control the tuner with a single push of the (TUNE) key on the front panel of the radio.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Connections for FT-450 1. Turn the tuner off. Set jumper JP2 to the “Y” position. 2. Make sure jumper JP4 inside the MFJ-925 is installed. 3. Before connecting the MFJ-5114Y to your radio, follow the instructions in the radio’s manual for installing the FC-30/-40 automatic antenna tuner. a. Press and hold the [F] button for one second to enter the Menu mode. The “MENU” icon will appear in the display. b.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Connections for FT-857 or FT-897 1. Turn the tuner off. Set jumper JP2 to the “Y” position. 2. Make sure jumper JP4 inside the MFJ-925 is installed. 3. Before connecting the MFJ-5114Y to your radio, follow the instructions in the radio’s manual for installing the FC-30 automatic antenna tuner. For the following, use the [FUNC] key and the [SELECT] knob on the FT-857, or use the [F] key and the [MEM/VFO CH] knob on the FT-897. a.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Connections for FT-950 1. Turn the tuner off. Set jumper JP2 to the “Y” position. 2. Make sure jumper JP4 inside the MFJ-925 is installed. 3. Before connecting the MFJ-5114Y to your radio, follow the instructions in the radio’s manual for installing the FC-40 automatic antenna tuner. a. Press the [MENU] button momentarily to enter the Menu mode. b. Rotate the [SELECT] knob to select Menu item [110 TGEN EXT TUN].
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Yaesu Radio Interface/MFJ-5114Y3 The MFJ-5114Y3 radio interface allows users of Yaesu FT-1000MP series, FT-2000 series, and FTDX9000 series transceivers to connect to the MFJ-925 IntelliTuner™ Automatic Antenna Tuner. With this interface, control signals are connected between the radio and the tuner.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual c. Rotate the [SUB VFO-B] knob to select 20 watts for best SWR accuracy. For the FT-2000D, we recommend that this be set to 50 watts if the user normally operates at 100 watts output power (when power is turned down to 100 watts, the TUNE power will reduce to 25 watts). If the operator normally has his FT-2000D set for the full 200 watts, then this should be set to 20 watts. d.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual Operation for FTDX-9000 series of radios The transceiver is controlled by the MFJ-925. To operate: 1. Press the [TUNE] button on the MFJ-925 for ½-2 seconds to initiate the tuning process. The radio will automatically transmit a low-power carrier and start the tuning process. When tuning is completed, the radio will stop transmitting and you will be ready for operation on this frequency.
MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual In Case of Difficulty If the tuner acts erratic, reset the tuner to factory defaults. If the tuner fails to tune, please double check all connections and follow the tuning procedures again. Be sure you are using enough inductance (through manual adjustment) and minimum capacitance. If the tuner arcs at the rated power levels, please double check all connections and follow the tuning procedures again.
32 Ground Antenna Capacitors 0-3900 pF Z Inductors 0-24 uH LEDs User Interface Push Buttons Microcontroller Frequency Counter Figure 13. MFJ-925 Circuit Block Diagram. Memory Relay Drivers Impedance Sensor Buzzer SWR Sensor RF Radio Interface Voltage Regulator DC Bias Tee Transmitter MFJ-925 Super-Compact IntelliTuner Automatic Antenna Tuner Instruction Manual © 2006-2010 MFJ Enterprises, Inc.
LIMITED 12 MONTH WARRANTY MFJ Enterprises, Inc. warrants to the original owner of this product, if manufactured by MFJ Enterprises, Inc. and purchased from an authorized dealer or directly from MFJ Enterprises, Inc. to be free from defects in material and workmanship for a period of 12 months from date of purchase provided the following terms of this warranty are satisfied. 1. The purchaser must retain the dated proof-of-purchase (bill of sale, canceled check, credit card or money order receipt, etc.
MFJ ENTERPRISES, INC. 300 Industrial Park Road Starkville, MS 39759 MFJ-925 Manual Version 1A Printed In U.S.A.
