MFJ -998 Instruction Manual
  1. Manuals
  2. Brands
  3. MFJ Manuals
  4. Tuner
  5. MFJ-998
  6. Instruction manual

MFJ -998 Instruction Manual

Automatic antenna tuner
Hide thumbs Also See for MFJ-998:
Table of Contents

Advertisement

Quick Links

Download this manual
Legal Limit IntelliTuner
TM
Automatic Antenna Tuner
Model MFJ-998
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
C
COPYRIGHT
2007-2010 MFJ ENTERPRISES, INC.
VERSION 1E

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the MFJ-998 and is the answer not in the manual?

Questions and answers

Related Manuals for MFJ MFJ-998

Summary of Contents for MFJ MFJ-998

  • Page 1 Legal Limit IntelliTuner Automatic Antenna Tuner Model MFJ-998 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 COPYRIGHT 2007-2010 MFJ ENTERPRISES, INC. VERSION 1E...
  • Page 2 Customers using this manual should report errors or omissions, recommendations for improvements, or other comments to MFJ Enterprises, 300 Industrial Park Road, Starkville, MS 39759. Phone: (662) 323-5869; FAX: (662) 323-6551. Business hours:...

  • Page 3: Table Of Contents

    MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual Contents THE BASICS Introduction............................1 Features............................2 Specifications........................... 2 Transceiver Protection ........................3 Amplifier Protection ........................3 Fast Start ............................4 Front Panel............................5 SWR/Wattmeter........................5 Wattmeter Zero Scale Adjustment..................5 Wattmeter Full Scale Adjustment..................
  • Page 4 MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual Tuner Indicators ..........................16 Antenna..........................16 Radio Interface........................16 Amp Relay Enable ......................16 Memory..........................17 LC Limit ........................... 17 Auto Range ........................17 Auto/Semi ......................... 17 StickyTune ........................17 Setup Mode Menus ........................18 Target SWR Menu ......................
  • Page 5 MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual Alinco Radio Interface........................32 Connections ........................32 Operation .......................... 32 Icom Radio Interface........................33 Connections ........................33 Operation .......................... 33 Kenwood Radio Interface ......................34 Connections ........................34 Operation .......................... 34 Yaesu Radio Interface/MFJ-5114Y ....................
  • Page 6 MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual Figure 17. Tuner Indicators......................17 Figure 18. Power-On Operations ....................26 Figure 19. MFJ-998 Circuit Block Diagram................. 43 TABLES Table 1. Memory Resolution ......................19 Table 2. Tuner Beeps ........................23 Table 3.

  • Page 7: The Basics

    Full Legal Limit automatic antenna tuning center with an internal SWR/wattmeter and an antenna switch for two antennas. The MFJ-998 lets you rapidly tune almost any unbalanced or single-wire antenna automatically. Balanced feedlines may be used with an MFJ-912 1.5 kW 4:1 balun connected to the MFJ-998 antenna output.

  • Page 8: Features

    (for Icom), MFJ-5114K (for Kenwood), and MFJ-5114Y/Y3/Y4 (for Yaesu) are available from MFJ Enterprises, Inc. The MFJ-998 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.

  • Page 9: Transceiver Protection

    When interfaced to your transceiver with the appropriate cable, the MFJ-998 automatically puts your transceiver into a low power CW tune mode when tuning is initiated. More details are provided in the “Radio Interface” section of this manual.

  • Page 10: Fast Start

    ● Never exceed tuner specifications. Connect the MFJ-998 to the transceiver, the amplifier, and the antenna as shown in Figure 1 and per the following directions: 1. Connect the MFJ-998 to a 12-15 VDC voltage source capable of supplying at least 1.4 amps.

  • Page 11: Front Panel

    SWR/Wattmeter: The cross-needle meter measures forward power, reflected power, and SWR. It operates whenever the MFJ-998 is powered on. Full-scale readings are 300 watts forward and 60 watts reflected power. The meter can be set to a high power range of 3000 watts forward and 600 watts reflected.

  • Page 12: Wattmeter Full Scale Adjustment

    MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual • Analog Meter Full Scale Adjustment: Two trimpots, located to the left of the LCD display, calibrate the full scales of the forward and reflected needles. The small hole on the top adjusts the forward needle and the small hole on the bottom adjusts the reflected needle.

  • Page 13: Tune Button

    (straight through from TRANSMITTER to ANTENNA 1 and WIRE) and the amplifier bypass control line is uninterrupted by the MFJ-998. When power is turned on, the tuner powers-up bypassed, but will revert to the last stored matching values or begin tuning on application of RF power when the [TUNE] button is pressed.

  • Page 14: Figure 3. Mode Button Flow Chart And Button Action

    MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual MODE BUTTON FLOW CHART MAIN MODES SETUP MODES 14.100MHz TARGET SWR Digital MODE FWD=1000 REF=5.0 Wattmeter AUTO TUNE SWR For 2 sec. 14.100MHz Power AMP BYPASS SWR 1000 Bar Meter METER RANGE MODE 14.100MHz...

  • Page 15: Back Panel

    12345678 +13.8 V DC input (1.4 A) tuner interface connector, a separate power Ground supply is necessary to power the MFJ-998 due Ground to its 1.4 amp power requirement. The MFJ- Key/TT/TX 998 should be powered on first (for certain...

  • Page 16: Jumper Jp1

    Jumper JP1 There is a jumper JP1 inside the MFJ-998 that must be configured properly when interfacing to the various radios. Normally this jumper is installed and is the factory default. Remove this jumper when interfacing to an Icom IC-7000.

  • Page 17: Figure 8. Kenwood Interface Cable

    This cable plugs into the REMOTE jack on the rear panel of the Yaesu radios, and keys the Yaesu radios in the CW tune mode whenever the MFJ-998’s [TUNE] button is pushed. MFJ recommends that the Yaesu CW tune setting be set to 10 watts (Yaesu MP menu selection 4-3) during the tune process when an amplifier is not used.

  • Page 18: Serial Port

    Figure 10. Yaesu Interface Cable (MP/2000/9000 series). While the MFJ-5114Y3 works with the FT-2000, the FT-2000 also has a TX REQ input that can be used. If you prefer to use the TX REQ input, the MFJ-5114Y4 interface provides control signals between the Yaesu FT-2000 and FT-2000D radios and the MFJ automatic tuner.

  • Page 19: Installation

    Note: Route all random wire antennas safely to prevent a RF burn hazard. • For balanced feedlines, connect an MFJ-912 1.5 kW 4:1 balun to the appropriate antenna connector output of the MFJ-998. 4. A GROUND post is provided for an RF ground connection. See “Grounding Hints” on page 24.

  • Page 20: The Menus

    SWR sensitivity adjustments are required with this meter. Figure 12 shows an SWR of approx. 1.2. The MFJ-998 also includes an SWR bar meter and an audio SWR indicator. It also has bar meters for forward and reflected power.

  • Page 21: Swr Bar Meter Menu

    MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual For low-power tuning, meter range of 300 watts is available. When in the low power range, each vertical bar segment consists of two dots. Below 100 watts, each bar segment represents two watts; above 100 watts, each bar segment represents 20 watts.

  • Page 22: Tuner Indicators

    MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual 2 3 4 Frequency Indicators: Antenna, Amp Relay , Interface Indicators: Memory, LC Limit, Auto Range 2 3 4 Indicators: Auto/Semi, StickyTune Forward power in watts Reflected power in watts 2 3 4...

  • Page 23: Memory

    MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual • Memory: A small “A”, “B”, “C” or “D” appears to indicator the selected memory bank when Memory is ON (23-26); nothing appears when Memory is OFF. • LC Limit: When LC Limit is OFF, a bar appears on top of the Memory indicator (27).

  • Page 24: Setup Mode Menus

    Instruction Manual Setup Mode Menus The setup mode menus allow you to customize how the MFJ-998 tuner operates. There are 13 setup mode menus arranged in a “wrap-around” structure. To access these setup menus, press and hold the [MODE] button for two seconds. The setup menu that will display is the one that was last used. When finished, press the [MODE] button for two seconds to go back to the main mode for normal operation.

  • Page 25: Meter Range Menu

    MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual WARNING: Amplifier Bypass Control is a safety precaution; the tuner and amplifier are in danger of being damaged if this function is turned off. Meter Range Menu Allows you to select the meter scale range. In the 300 watts (low) range, the forward full scale is 300 watts and the reflected full scale is 60 watts.

  • Page 26: Intellitune Menu

    MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual To clear an antenna memory bank, select the antenna memory bank with the [ANT] button and turn off the power to the tuner. Then press and hold both [TUNE] and [C-UP] buttons while turning on the power.

  • Page 27: Push Tune <0.5S Menu

    MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual Note: When exiting the setup mode, TURN POWER OFF message will display if the Radio Interface menu setting has changed. Turn the tuner’s power off, connect the new radio interface, then on again to re-initialize the radio interface circuitry.

  • Page 28: Morse Code And Beeps

    MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual Manual tuning of inductance is similarly accomplished, using [L-UP] and [L-DN]. Since the capacitance and inductance are interdependent, some back-and-forth between the two may be needed, just as in a conventional tuner with knobs.

  • Page 29: Transceiver Foldback

    Check your transceiver owner's manual to see if it has a foldback circuit. When an amplifier is used, the amplifier must be bypassed during tuning. Note: MFJ recommends that a transceiver-specific interface cable be used between the MFJ-998 and your transceiver, and that an amplifier enable/bypass connection be used between the MFJ-998 and your amplifier, to ensure that tuning only occurs at low power.

  • Page 30: Grounding Hints

    When the SWR rises, the power handling capability decreases by 1/√SWR and loss also increases. Therefore MFJ recommends that RG-8/U, RG-213, LMR-400 or other high quality coax cables be used between the MFJ-998 output and the antenna. Refer to The Radio Amateurs Handbook and The ARRL Antenna Book for more information.

  • Page 31: Matching Problems

    MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual located as high and clear as possible. While good RF grounds help the signal in almost any transmitting installation, it is extremely important to have good RF grounds with long wire or other Marconi-style antennas.

  • Page 32: Appendices

    MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual Appendices POWER-ON OPERATIONS (Press and hold buttons while turning on the power.) Press and hold TUNE POWER to start the self test. Press and hold to test the relays. C-DN POWER Press and hold to test the power-down circuitry.

  • Page 33: Disable Radio Interface

    DEFAULTS RESET Resume normal operation. WARNING: If the MFJ-998 is not behaving properly or is acting erratically, try resetting the tuner to factory defaults. Disable Radio Interface If the wrong radio interface is selected and the...

  • Page 34: Self Test

    Instruction Manual Self Test A self-test routine will check the functions of the MFJ-998. This routine checks the display, the front- panel buttons, the internal memory, the audio circuitry, and the power-down circuitry. During the self- test, 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.

  • Page 35: Power-Down Circuit Test

    MFJ-998 Legal Limit 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.

  • Page 36: Swr Bridge Calibration

    WARNING: Do not touch anything inside the tuner during operation! Serious, painful RF burns can result. WARNING: Never operate the MFJ-998 with its cover removed; dangerous voltages and currents can be present during operation. Never exceed tuner specifications. 1. Turn off the power to the tuner and the transmitter.

  • Page 37: Frequency Counter Calibration

    WARNING: Do not touch anything inside the tuner during operation! Serious, painful RF burns can result. WARNING: Never operate the MFJ-998 with its cover removed; dangerous voltages and currents can be present during operation. Never exceed tuner specifications. 1. Turn off the power to the transmitter and the tuner.

  • Page 38: Alinco Radio Interface

    6. Push the [POWER] button on the tuner to the in position and then power on the radio. Operation The operation of the MFJ-5114A radio interface is similar to the operation of the EDX-2 described in the Alinco operating manual.

  • Page 39: Icom Radio Interface

    Push [PWR] to turn power on again. Operation The operation of the MFJ-5114I radio interface is similar to the operation of the AH-3 or AH-4 described in the Icom radio’s operating manual. 1. Push and hold the [TUNER] button on the radio for one or two seconds to initiate automatic tuning process.

  • Page 40: Kenwood Radio Interface

    Press the [CLR] key to return to normal operation. Operation The operation of the MFJ-5114K radio interface is similar to the operation of the AT-300 described in the Kenwood radio’s operating manual. 1. Press and hold the [AT TUNE] button on the radio for one second to initiate automatic tuning process.

  • Page 41: Yaesu Radio Interface/Mfj-5114Y

    8. Push the [POWER] button on the tuner to the in position and then power on the radio. Operation for FT-100 The operation of the MFJ-5114Y radio interface is similar to the operation of the FC-20 described in the Yaesu radio’s operating manual.

  • Page 42: Connections For Ft-450

    8. Push the [POWER] button on the tuner to the in position and then power on the radio. Operation for FT-450 The operation of the MFJ-5114Y radio interface is similar to the operation of the FC-30/-40 described in the Yaesu radio’s operating manual.

  • Page 43: Connections For Ft-857 Or Ft-897

    8. Push the [POWER] button on the tuner to the in position and then power on the radio. Operation for FT-857 or FT-897 The operation of the MFJ-5114Y radio interface is similar to the operation of the FC-30 described in the Yaesu radio’s operating manual.

  • Page 44: Connections For Ft-950

    8. Push the [POWER] button on the tuner to the in position and then power on the radio. Operation for FT-950 The operation of the MFJ-5114Y radio interface is similar to the operation of the FC-40 described in the Yaesu radio’s operating manual.

  • Page 45: Yaesu Radio Interface/Mfj-5114Y3

    With this cable the operator can control the tuner and radio with a single push of the [TUNE] button on the front panel of the MFJ-998. Connections for FT-1000MP series of radios 1.

  • Page 46: Operation For Ft-2000 Series Of Radios

    5. Connect a 12V 1.5 amp DC source to the MFJ-998. 6. Push the [POWER] button on the MFJ-998 to the in position. The radio may be powered on either before or after the tuner is powered on.

  • Page 47: Operation For Ft Dx -9000 Series Of Radios

    (REMOTE) input. If this option is chosen, you must use the MFJ-5114Y4 radio interface cable. With this interface, control signals are connected between the radio and the tuner. With this cable the operator can control the tuner and radio with a single push of the [TUNE] button on the front panel of the MFJ- 998.

  • Page 48: In Case Of Difficulty

    If you have any problem with this unit first check the appropriate section of this manual. If the manual does not reference your problem or your problem is not solved by reading the manual, you may call MFJ Technical Service at 662-323-0549 or the MFJ Factory at 662-323-5869. You will be best helped if you have your unit, manual and all information on your station handy so you can answer any questions the technicians may ask.

  • Page 49: Circuit Block Diagram

    MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual © 2007-2010 MFJ Enterprises, Inc.
  • Page 50 MFJ-998 Legal Limit IntelliTuner Automatic Antenna Tuner Instruction Manual Notes © 2007-2010 MFJ Enterprises, Inc.
  • Page 51 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.
  • Page 52 MFJ ENTERPRISES, INC. MFJ-998 Manual 300 Industrial Park Road Version 1E Starkville, MS 39759 Printed In U.S.A. 02/2010...

This manual is also suitable for:

Legas limit intellituner mfj-998

Table of Contents

Save PDF