MFJ IntelliTuner MFJ-993B User manual

INSTRUCTION MANUAL
CAUTION: Read All Instructions Before Operating Equipment
MFJ ENTERPRISES, INC.
300 Industrial Park Road
Starkville, MS 39759 USA
Tel: [phone] Fax: [phone]
COPYRIGHT 200 MFJ ENTERPRISES, INC.5
C
Model MFJ-993B
VERSION 1A
IntelliTuner
Automatic Antenna Tuner
TM

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
i
Contents
THE BASICS
Introduction...................................................................................................................................... 1
Features............................................................................................................................................ 2
Specifications................................................................................................................................... 2
Fast Start .......................................................................................................................................... 3
Front Panel....................................................................................................................................... 4
SWR/Wattmeter.................................................................................................................. 4
LCD Display ....................................................................................................................... 4
LCD Contrast Control......................................................................................................... 4
ANT Button ........................................................................................................................ 4
MODE Button.....................................................................................................................4
C-UP and C-DN Buttons .................................................................................................... 4
L-UP and L-DN Buttons..................................................................................................... 5
AUTO Button .....................................................................................................................5
TUNE Button...................................................................................................................... 5
VOL Control ....................................................................................................................... 5
POWER Button................................................................................................................... 5
Back Panel ....................................................................................................................................... 7
Power .................................................................................................................................. 7
Remote Port ........................................................................................................................ 7
Radio Interface.................................................................................................................... 7
Transmitter.......................................................................................................................... 8
Ground ................................................................................................................................ 8
Balanced Line ..................................................................................................................... 9
Wire .................................................................................................................................... 9
Antenna 1............................................................................................................................ 9
Antenna 2............................................................................................................................ 9
Installation ....................................................................................................................................... 9
SWR/Wattmeter............................................................................................................................. 10
THE MENUS
Main Mode Menus......................................................................................................................... 11
Digital Wattmeter Menu ................................................................................................... 11
Power Bar Meter Menu..................................................................................................... 11
SWR Bar Meter Menu ...................................................................................................... 12
L-Network Menu .............................................................................................................. 12
Tuner Indicators............................................................................................................................. 13
Antenna............................................................................................................................. 13
IntelliTune......................................................................................................................... 13
Memory............................................................................................................................. 13
Power Level ...................................................................................................................... 13
LC Limit ........................................................................................................................... 14
Meter Range...................................................................................................................... 14

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
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Auto/Semi ......................................................................................................................... 14
StickyTune........................................................................................................................ 14
Setup Mode Menus ........................................................................................................................ 15
Power Level Menu............................................................................................................ 15
Target SWR Menu ............................................................................................................ 15
Auto Tune SWR Menu ..................................................................................................... 15
Meter Range Menu ........................................................................................................... 16
Peak Hold Menu ............................................................................................................... 16
Memory Menu .................................................................................................................. 16
IntelliTune Menu .............................................................................................................. 17
SWR Beep Menu .............................................................................................................. 17
Beep Menu........................................................................................................................ 17
Refresh Menu.................................................................................................................... 17
LC Limit Menu ................................................................................................................. 18
OPERATION
Manual Tuning............................................................................................................................... 18
Meter Codes and Audible Beeps.................................................................................................... 19
Foldback Circuit ............................................................................................................................ 20
Grounding Hints ............................................................................................................................ 21
Antenna System Hints.................................................................................................................... 21
Location ............................................................................................................................ 21
Matching Problems ........................................................................................................... 21
APPENDICES
Resetting the Tuner........................................................................................................................ 23
Factory Defaults................................................................................................................ 23
Delete Antenna Memory................................................................................................... 24
Total Reset ........................................................................................................................ 24
Self Test ......................................................................................................................................... 24
Power Down Circuit Test............................................................................................................... 25
Relay Test ...................................................................................................................................... 26
Firmware Version Number via Meter............................................................................................ 26
Setting the Speaker Volume........................................................................................................... 26
Wattmeter Calibration.................................................................................................................... 27
SWR Bridge Calibration ................................................................................................................ 27
Frequency Counter Calibration...................................................................................................... 28
In Case of Difficulty ...................................................................................................................... 29
Technical Assistance...................................................................................................................... 29
List of Accessories......................................................................................................................... 29
Circuit Block Diagram................................................................................................................... 30

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
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FIGURES
Figure 1. Installation Block Diagram.............................................................................................. 3
Figure 2. MFJ-993B Front Panel .................................................................................................... 4
Figure 3. Mode Button Flow Chart and Button Action .................................................................. 6
Figure 4. MFJ-993B Back Panel..................................................................................................... 7
Figure 5. Alinco Interface Cable..................................................................................................... 8
Figure 6. Icom Interface Cable ....................................................................................................... 8
Figure 7. SWR/Wattmeter ............................................................................................................ 10
Figure 8. Power Bar Meter (High Range)..................................................................................... 12
Figure 9. Power Bar Meter (Low Range) ..................................................................................... 12
Figure 10. SWR Bar Meter ........................................................................................................... 12
Figure 11. Main Mode Menus Display ......................................................................................... 13
Figure 12. Tuner Indicators........................................................................................................... 14
Figure 13. Power-On Operations .................................................................................................. 23
Figure 14. MFJ-993B Circuit Block Diagram .............................................................................. 30
TABLES
Table 1. Memory Resolution ........................................................................................................ 16
Table 2. Meter Needle Stationary Codes ...................................................................................... 19
Table 3. Meter Needle Bounce Codes .......................................................................................... 20
Table 4. Failure Messages............................................................................................................. 25

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
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MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
1
The Basics
Introduction
The MFJ-993B IntelliTunerTM lets you rapidly tune any antenna automatically: balanced, unbalanced, or
single-wire. The MFJ-993B is a comprehensive automatic antenna tuning center with SWR/wattmeter,
antenna switch for two antennas, and a 4:1 current balun for balanced lines.
MFJ's exclusive InstantRecallTM, IntelliTuneTM and AdaptiveSearchTM algorithms give you fast automatic
tuning with more than 20,000 non-volatile VirtualAntennaTM memories. Each of the two antennas has
four banks of memory; each memory bank has over 2500 non-volatile memories for tuner settings.
The tuner includes a highly efficient switching L-network with wide matching capability, 1.8 to 30 MHz
coverage, cross-needle power meters, backlight LCD display, a port for an accessory remote control, a
radio interface port, and heavy-duty 16 amp/1000 volt relays. It is rated at 300 watts to match 6 to 1600
ohms antennas (SWR up to 32:1) or 150 watts to match wider range of 6 to 3200 ohms (SWR up to 64:1).
A maximum of 256 values of inductance and 256 values of capacitance are available. With the
capacitance switched between the input and output side, this provides a total of 131,072 L/C tuning
combinations. The nominal tuning ranges are 0 to 24 μH and 0 to 3900 pF.
All MFJ IntelliTunersTM learn and remember. When you transmit, they automatically adjust for minimum
SWR and remember the frequency and tuner settings, safely stored in non-volatile memory. The next
time you operate on that frequency (or close to it) and antenna, these tuner settings are instantly restored
and you’re ready to operate in milliseconds. Each of two antenna selections has four banks of memory,
which can learn and remember more than 2500 frequencies and tuner settings per bank.
When you key your transmitter, MFJ’s InstantRecallTM checks its memory to see if you have operated
that frequency before. If so, tuning is instantaneous and you’re ready to operate. If not, MFJ’s
IntelliTuneTM algorithm (based on MFJ’s famous SWR Analyzer technology) kicks in. It measures the
complex impedance of your antenna. Next, it calculates the components it needs and instantly snaps them
in. Finally, it fine-tunes to minimize SWR, and you’re ready to operate--all in a fraction of a second.
If the antenna impedance is not within the tuner’s measurement range, MFJ’s AdaptiveSearchTM
algorithm goes into action. Frequency is measured and relevant components values are determined. Only
those values are searched for fast tuning. If it still cannot find a match, the search is performed again
using a different search pattern.
The target SWR can be set at 1.0 through 2.0. The minimum power to tune is approximately two watts.
You can manually tune where you can’t transmit (for listening out of ham bands).
All MFJ’s IntelliTunersTM support radio tuner interfaces that are compatible with Alinco EDX-2 tuner,
Icom AH-3 and AH-4 tuners, Kenwood AT-300 tuner, Yaesu FC-30 tuner, and certain Yaesu radios with
CAT system. Optional interface cables MFJ-5124A (for Alinco), MFJ-5124I (for Icom), MFJ-5124K (for
Kenwood), MFJ-5124Y and MFJ-5124Y2 (for Yaesu) are available from MFJ Enterprises, Inc. The
optional MFJ-993RC Remote Control provides most tuner controls, allowing convenient remote locating
of the tuner itself.
The tuners enter a “sleep” mode when idle and when no transmit signal is present, turning off the
microprocessor clock to avoid the generation of spurious signals.

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
2
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)
• Tune in less than 15 seconds, usually less than 5 seconds
• Over 20,000 non-volatile memories for tuner settings
• Four memory banks per antenna with over 2500 memories per bank
• Highly efficient switching L-network matching circuit
• 1.8 to 30 MHz continuous frequency coverage
• Adjustable target SWR 1.0 to 2.0
• Adjustable SWR threshold 0.5 to 1.5
• Lighted cross-needle SWR/wattmeter with high, low, and auto range options
• Multifunction backlit LCD display with contrast control
• Numeric readings for SWR, forward and reflected power
• Bar meters for SWR, forward and reflected power with range options
• Audio SWR meter with volume control
• Built-in frequency counter
• Two SO-239 coax fed antenna connectors
• Connector for random wire or single wire antennas
• Built-in 4:1 current balun for balanced line antennas
• Optional remote control
• Optional radio interface 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
• 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
• Frequency counter range: up to 50 MHz
• Capacitance range: 0 to 3908 pF nominal (256 values)
• Inductance range: 0 to 24.86 μH nominal (256 values)
• Relay rating: 16 amp 1000 volts
• Relay electrical life: 100,000 operations
• Relay mechanical life: 10 million operations
• Memory endurance: 1 million erase/write cycles
• Memory data retention: > 200 years
• Power requirements: 12 - 15 volts DC, 2.1 × 5.5 mm coaxial plug, center pin positive
• Current consumption: 1 amp or less
• Dimensions (approx.): 10.1 × 2.8 × 9.2 in. (257 × 71 × 234 mm) (width/height/depth)
not including connectors
• Weight (approx.): 3.9 lb (1.77 kg)
† Specifications and design are subject to change without notice.

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
3
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 and balanced line connection may have high voltage while transmitting.
●Disconnect all antennas from the tuner during lightning storms.
●Always tune with low power (about 10 watts). Apply maximum power only after tuning up.
●Never exceed tuner specifications.
●Do not transmit with a high SWR for extended periods of time.
1. Connect the MFJ-993B to a 12-15 VDC voltage source capable of supplying at least 1 amp.
2. Connect your transmitter to the TRANSMITTER connector using a 50-ohm coaxial cable.
3. Connect your coax-fed antenna to the ANTENNA 1 connector using a 50-ohm coaxial cable, or
connect your random wire to the WIRE binding post, or connect your balanced line antenna to the
BALANCED LINE binding posts and connect a jumper between the other two posts as indicated.
4. Connect your ground connection to the GROUND post.
5. Press the [POWER] button to turn on the MFJ-993B tuner. Place the [ANT] button in the out
position to select antenna 1. Press the [AUTO] button in to select semi-automatic mode.
6. Key your transmitter to output a carrier of 10 watts CW, FM or AM.
7. Press and hold the [TUNE] button on the MFJ-993B for one second to start the automatic tuning
process. When completed, check to ensure an SWR of 2.0 or less before increasing RF power.
8. You are ready to transmit.
Note: During the automatic tuning process, the tuner will make some noise. These are the relays
switching at a very fast pace and it is normal operation. Do not be alarmed.
Note: When the tuner power is OFF, the tuner is in bypass mode and RF from the transmitter goes
directly to the antenna (ANTENNA 1) with no matching. When the tuner power is ON,
pressing [C-DN] and [L-DN] simultaneously or pressing [TUNE] quickly places the tuner in
bypass mode (zero inductance and zero capacitance) and indicates by the reflected needle
bouncing to 20 watts.
Transmitter MFJ-993B
50-ohm Coax
Antenna 1
RF Ground 12 VD
C
A
ntenna 2
Figure 1. Installation Block Diagram.

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
4
Front Panel
0
10
30
50
100
200
300
0
5
20
40
60
8
5.0
3.0 2.0
1.5
1.2
Hi x1
Lo x.1
400-3083
1
10
MODEL
MFJ-993B
ANT C-UP L-UP AUTO POWER
MODE C-DN L-DN TUNE
LCD VOL
AUTOMATIC ANTENNA TUNER
MFJ IntelliTuner
TM
Dual Power Level
300/150 Watts
Z
BYPASS
SWR
14.100MHz 1.1
FWD=100 REF=0.5
11.2 1.52 3SWR
0255075100PWR 300
Figure 2. MFJ-993B Front Panel.
• SWR/Wattmeter: The cross-needle meter measures forward power, reflected power, and SWR. It
operates whenever the tuner is power on. Full-scale readings are 300 watts forward and 60 watts
reflected. The meter can be set to low power range of 30 watts forward and 6 watts reflected. The
SWR is measured at the point where the two needles cross. See “SWR/Wattmeter” on page 10 for
more detailed information.
• LCD Display: A 2-line by 16-character alphanumeric display. It displays the tuner’s various menus
and status. The display contrast can be adjusted by the [LCD] control on the front panel. Below the
display are the SWR and power bar meter scales. Refer to Figures 11 and 12 for descriptions of the
various displayed information.
• LCD Contrast Control: A trimpot control that adjusts the contrast of the LCD display. Use a small
flat blade screwdriver and turn clockwise to increase contrast.
• ANT Button: Used to select the antenna to tune. Button out selects Antenna 1; button in selects
Antenna 2. The Antenna indicator on the main display indicates the selected antenna. A balanced
feedline or a single-wire antenna is, by default, Antenna 1. Changing the [ANT] button will switch
the antenna only when there is no RF power; also, the tuner setting for the selected antenna, if
available, is instantly restored from memory when enabled.
• MODE Button: Time-sensitive and used to navigate through the various main menus and to enter or
exit the setup menus.
• C-UP and C-DN Buttons: Used to manually increase or decrease the capacitance of the L-network
matching circuit. The capacitance range is 0 to 3908 pF (picofarads). The upper limit of capacitance,
dependent on frequency, is used to limit the maximum voltage and current across the tuner’s
components. This limit can be removed in the LC Limit setup menu, but is not recommended.
Note: Pressing [C-UP] and [C-DN] simultaneously toggles the capacitor between the input
and output sides of the L-network. Forward needle bounces to 30 watts when the
capacitor is on the transmitter side. Reflected needle bounces to 5 watts when the
capacitor is on the antenna side.

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
5
• L-UP and L-DN Buttons: Used to manually increase or decrease the inductance of the L-network
matching circuit. The inductance range is 0 to 24.86 μH (microhenries). The upper limit of
inductance, dependent on frequency, is used to limit the maximum voltage and current across the
tuner’s components. This limit can be removed in the LC Limit setup menu, but is not recommended.
Shortcut: Press both [L-UP] and [L-DN] buttons simultaneously to toggle SWR Beep on and
off. See “SWR Beep Menu” on page 17.
Note: Pressing [C-DN] and [L-DN] (both DOWN buttons) simultaneously places the tuner in
bypass mode. The reflected needle bouncing to the 20-watt mark indicates this. RF from
the transmitter goes directly to the antenna with no matching.
• AUTO Button: Used to select automatic or semi-automatic tuning mode. Button out selects
automatic mode--the tuning routine is automatically started when at least 2 watts of power is applied
and the SWR is a preset amount above the preset target SWR. Button in selects the semi-automatic
mode--the tuning routine starts only when the [TUNE] button is pressed. The Auto/Semi indicator on
the main display indicates the selected mode.
Note: During the tuning process, the tuner will make some noise. These are the relays
switching at a very fast pace and it is normal operation. Do not be alarmed.
• TUNE Button: Has three different functions based on the length of time you press and hold it before
releasing. Press [TUNE] quickly (less than 0.5 second) to bypass the tuner. RF from the transmitter
goes directly to the antenna with no matching.
Press and hold [TUNE] for 0.5 to 2 seconds to start the automatic tuning process. The transmitter
must be keyed first with at least 2 watts of power. When the SWR is already below the target SWR,
pressing [TUNE] will fine-tune the match for a lower SWR, if possible.
“StickyTune” allows for one-handed tuning operation. Normal tuning requires keying the transmitter
with one hand and using the other hand to push the [TUNE] button to start the tuning process. To
toggle the StickyTune mode on and off, press and hold the [TUNE] button for two seconds. When
enabled, a bar appears on top of the Auto/Semi indicator, and the tuning process starts automatically
when the transmitter is keyed with at least 2 watts of power regardless of the SWR. This works in
both automatic and semi-automatic modes. One beep indicates on and two beeps indicate off.
• VOL Control: A trimpot control that adjusts the volume level of the audio SWR meter. Use a small
flat blade screwdriver and turn clockwise to increase volume level.
• POWER Button: Used to turn the power on and off. Note that during power-on the analog meter
bounces three times (to indicate the model number, 993). When the power is off, the tuner is placed
in bypass mode and Antenna 1 is selected. When turning on the power, the tuner automatically
restores all previous settings and displays the target SWR on the main screen.
WARNING: Do not turn the power on and off rapidly, otherwise the tuning setting
memory can be corrupted and the unit will have to be reset to factory defaults.
Note: When the tuner power is OFF, the tuner is in bypass mode and RF from the transmitter
goes directly to the antenna (ANTENNA 1) with no matching.

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
6
MODE BUTTON FLOW CHART
SETUP MODESMAIN MODES
For 2 sec.
MODE
For 2 sec.
or
Idle for 8 sec.
MODE
TUNE C-UP
L-UPTUNE
C-DN L-DN
L-DNL-UP
C-UP C-DN
Press + to switch the capacitor between the input and output side.
Press + to toggle the SWR Beep on and off.
Press + to bypass the antenna tuner.
Press + to cycle the Auto Tune SWR among 0.5, 1.0 and 1.5 above the target SWR.
Press + to toggle the Target SWR between 1.5 and 2.0.
TUNE C-DN
Press + to cycle the Memory among banks A, B, C and D.
TUNE L-DN
Press + to cycle the Meter Range among 30 watts, 300 watts and auto range.
BUTTON ACTION
Press + to increase both capacitance and inductance.
C-UP L-UP
MODE
AUTO
ANT
C-UP
L-UP
C-DN
L-DN
TUNE
POWER
Press less than 0.5 second to bypass the tuner; press and hold for 0.5 to 2 seconds to start the
tuning process; press and hold for more than two seconds to toggle the StickyTune on and off.
Press in to select semi-automatic mode,
out to select automatic mode.
Press to decrease inductance.
Press to increase inductance.
Press to decrease capacitance.
Press to increase capacitance.
Press to switch main modes and setup modes.
Press in to select antenna 2, out to select antenna 1.
Press in to turn power on, out to turn power off.
Press or to turn on
or increase setting.
C
-UP L-UP
C
-DN L-DN
Press or to turn off
or decrease setting.
(while in the main modes)
Press + to overwrite tuner memory with the current tuner setting.+
TUNE L-DNC-DN
Press + to+ toggle the power level between 300 and 150 watts.
TUNE C-UP L-UP
Digital
Wattmeter
Power
Bar Meter
SWR
Bar Meter
L-Network
MODE
14.100MHz 1.1
FWD=100 REF=0.5
14.100MHz 1.1
100
0.00uH 1,0
0pF 100
14.100MHz 1.1
100
POWER LEVEL
TARGET SWR
AUTO TUNE SWR
METER RANGE
PEAK HOLD
MEMORY
IntelliTune
SWR BEEP
BEEP
REFRESH
LC LIMIT
MODE
MODE
+
MODE
C-UP
L-UP
+
Figure 3. Mode Button Flow Chart and Button Action.

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
7
Back Panel
RADIO
INTERFACE
+
POWER
12VDC
1A
REMOTE
PORT
ANTENNA 1 ANTENNA 2
TRANSMITTER
BALANCED LINE
GROUND
WIRE
MFJ ENTERPRISES, INC.
STARKVILLE, MS USA
!
Do not connect WIRE and
ANTENNA 1 at same time!
Install Jumper When Using
BALANCED LINE Antenna
*
*
Figure 4. MFJ-993B 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 volts DC at up to 1 amp. The use of a regulated supply is not
mandatory but is recommended for best performance. An optional 12 volts DC 1.5 amp power
supply, the MFJ-1316, is available from MFJ Enterprises, Inc.
WARNING: Do not apply voltages greater than 18 volts to this unit, or permanent damage
to the unit may result.
Note: When the tuner power is OFF, the tuner is in bypass mode and RF from the transmitter
goes directly to the antenna (ANTENNA 1) with no matching.
• Remote Port: A female DB-9 connector for connecting to the MFJ-993RC Remote Control,
allowing remote operation of the tuner. The MFJ-993RC duplicates all the front panel buttons except
[POWER] and [MODE]. In addition, there are two LEDs on the remote control. The red Tuning
LED lights to indicate tuning is in progress and the green SWR LED lights when the SWR is below
the target SWR.
Note: To use the remote control, both the [ANT] and [AUTO] buttons on the automatic tuner
must be pressed in; otherwise, Antenna 1 and Automatic mode are selected.
• Radio Interface: A 3.5 mm stereo phone jack for connecting to the tuner interface connector of
compatible radios. Most radios provide +13.8 VDC power thought its tuner interface connector. If
separate power supplies are used to power the MFJ-993B, the MFJ-993B should be powered on first
(for certain radios, TURN ON RADIO will display and both needles will bounce) and then turn on
the radio, so the radio knows an external tuner is attached. The radio will disable its internal tuner, if
it has one, and use the external tuner.
The Radio Interface works with radios that are compatible with Alinco EDX-2, Icom AH-3 and AH-
4, Kenwood AT-300, Yaesu FC-30, and certain Yaesu radios with CAT system. When connected to
a compatible radio, simply press the [TUNER] or [AT] button on the radio; for certain Yaesu, press
the [TUNE] button on the tuner to start the automatic tuning process. The radio will automatically
switch to CW mode (AM for Yaesu), transmit a 10-watt carrier, and start the tuning process. Once
the automatic tuning is completed, the radio will return to its previous mode and power setting.

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
8
WARNING: Make sure the +13.8 volts connection on the radio’s tuner port is capable of
supplying at least 1 amp of current, since the MFJ-993B uses up to 1 amp.
The MFJ-5124A interface cable provides power and control between an Alinco radio and the MFJ
automatic tuner. Supported Alinco radios are DX-70, DX-77, and any Alinco radio that supports the
Alinco EDX-2 tuner.
Pin 3 (Key) connects to the Tip of 3.5 mm Stereo Phone Plug.
Pin 5 (Start) connects to the Ring of 3.5 mm Stereo Phone Plug.
Pin 2 (+13.8V) connects to the Center Pin of Power Plug.
Pin 1 (Ground) connects to the Sleeves of both 3.5 mm Stereo Phone Plug and Power Plug.
Pin 4 is not connected.
Figure 5. Alinco Interface Cable.
The MFJ-5124I interface cable provides power and control 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-765, IC-775, and any Icom radio that supports the Icom AH-3 and AH-4 tuners.
Push and hold the radio’s [TUNER] button for two seconds to start the tuning process. Push
[TUNER] quickly to bypass the tuner.
Pin 1 (Key) connects to the Tip of 3.5 mm Stereo Phone Plug.
Pin 2 (Start) connects to the Ring of 3.5 mm Stereo Phone Plug.
Pin 3 (+13.8V) connects to the Center Pin of Power Plug.
Pin 4 (Ground) connects to the Sleeves of both 3.5 mm Stereo Phone Plug and Power Plug.
Figure 6. Icom Interface Cable.
The MFJ-5124K interface provides power and control between a Kenwood radio and the MFJ
automatic tuner. Supported Kenwood radios are TS-50S, TS-450S, TS-480HX, TS-570S, TS-690S,
TS-850S, TS-870S, TS-2000, and any Kenwood radio that supports the Kenwood AT-300 tuner.
Push and hold the radio’s [AT TUNE] button for one second to start the tuning process. Push the [AT
TUNE] quickly to bypass the tuner or to cancel tuning in progress.
The MFJ-5124Y interface provides power and control between a Yaesu radio and the MFJ automatic
tuner. Supported Yaesu radios are FT-857, FT-897, and any Yaesu radio that supports the Yaesu FC-
30 tuner—press and hold in the [A](TUNE) key on the radio for one second to initiate automatic
tuning. Supported Yaesu radios are FT-100, FT-857, FT-897, and any Yaesu radio with compatible
CAT system—push the [TUNE] button on the tuner for 0.5 to 2 seconds to start the tuning process.
The MFJ-5124Y2 interface provides control between a Yaesu radio and the MFJ automatic tuner.
Supported Yaesu radios are FT-847 and any Yaesu radio with compatible CAT system. Push the
[TUNE] button on the tuner for 0.5 to 2 seconds to start the tuning process.
• Transmitter: SO-239 connector for coax cable from transmitter or transceiver.
• Ground: Wing-nut terminal for RF ground wire connection.

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
9
• Balanced Line: Two binding posts for connecting balanced line antennas. To use balanced line
antenna, install a jumper as shown to the WIRE binding post.
• Wire: Binding post for connecting single wire antennas. Notice the WIRE binding post is internally
connected to the ANTENNA 1 connector.
Note: To use the WIRE binding post, make sure to remove the antenna, if any, from the
ANTENNA 1 connector.
• Antenna 1: SO-239 connector for coax cable from antenna. Notice the ANTENNA 1 connector is
internally connected to the WIRE binding post.
Note: To use the ANTENNA 1 connector, make sure to remove the jumper and wire antenna, if
any, from the WIRE binding post.
• Antenna 2: SO-239 connector for coax cable from antenna.
Installation
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 and balanced line connection may have high voltage while transmitting.
●Disconnect all antennas from the tuner during lightning storms.
●Always tune with low power (about 10 watts). Apply maximum power only after tuning up.
●Never exceed tuner specifications.
●Do not transmit with a high SWR for extended periods of time.
1. Place the tuner in a convenient location at the operating position. With a random wire or balanced
line, the feed through insulators may have high RF voltages. These voltages can cause serious RF
burns if the terminals are touched when transmitting. Be sure to locate the tuner so these terminals
cannot accidentally be contacted during operation.
2. Install the tuner between the transmitter and the antenna. Use a 50-ohm coaxial cable (such as RG-
58) to connect the transmitter (or amplifier) to the connector marked TRANSMITTER on the rear of
the tuner. See Figure 1 on page 3.
3. Connect the antenna(s) to the tuner as follows:
• Coaxial feedlines to the SO-239 connectors labeled ANTENNA 1 and/or ANTENNA 2.
• Random wire or single wire line antennas should be connected to the WIRE binding post on the
back of the tuner (and remove the jumper wire). Note the back panel warning: Do not connect
WIRE and ANTENNA 1 at same time! When a single wire antenna is connected it “becomes”
ANTENNA 1.
Note: Route all single and random wire antennas safely to prevent RF burn hazard.

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
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• For a balanced feedline (open wire, twinlead, or twin-axial lines), place a jumper wire as
indicated on the back panel and connect the balanced feedline to the BALANCED LINE binding
posts. This antenna becomes ANTENNA 1. See “Antenna System Hints” on page 21.
4. A GROUND post is provided for an RF ground connection. See “Grounding Hints” on page 21.
5. Connect a 12 to 15 VDC power source to the input jack labeled POWER.
SWR/Wattmeter
The backlit cross-needle meter measures forward power,
reflected power, and SWR, and operates whenever the tuner is
powered on. Forward power up to 300 watts is displayed on the
left-hand FORWARD meter scale. Reflected power up to 60
watts is read on the right-hand REFLECTED meter scale. For
low-power tuning, meter ranges of 30 watts forward and 6 watts
reflected are available. Divide the readings on these scales by
ten when in the low power meter range.
The meter can be set to low, high, or auto range. Auto range
automatically sets the meter scales according to the input RF power to the tuner. Forward power greater
than 30 watts or reflected power greater than six watts automatically sets the meter to the high power
range. Forward power less than 25 watts and reflected power less than four watts automatically set the
meter to the low power range. To cycle the meter range among low, high, and auto range, press the
[TUNE] and [L-DN] buttons simultaneously. The forward needle will read “300” for high range, “30” for
low range, and “100” for auto range until the buttons are released. When auto range is enabled, a two-dot
vertical segment (low range) or a three-dot vertical segment (high range) appears in the lower right corner
of the Range indicator on the main LCD screen. One beep indicates high range is selected; two beeps
indicate low range; three beeps indicate auto range. Refer to Figures 11 and 12 for the on-screen Range
indicator.
The SWR is read from the eight red SWR curves that range from
1.0 to infinity. The SWR is measured by observing the point
where the forward and reflected power needles cross on the red
curved scales across the center of the meter. No cumbersome or
time-consuming SWR sensitivity adjustments are required with
this meter. Figure 7 shows an SWR of approximately 2.0.
The meter also indicates various operational states of the tuner. Refer to “Meter Codes and Audible
Beeps” on page 19 for more details.
The MFJ-993B also includes an SWR bar meter and an audio SWR indicator, selectable by pressing [L-
UP] and [L-DN] buttons simultaneously. It also has bar meters for forward and reflected power.
0
10
30
50
100
200
300
0
5
20
40
60
8
5.0
3.0 2.0
1.5
1.2
Hi x1
Lo x.1
400-3083
1
10
Figure 7. SWR/Wattmeter.
reflected power
1forward power
reflected power
1forward power
SWR
+
=
−

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
11
The Menus
Main Mode Menus
The main mode menus show various tuner settings and status. There are four main mode menus arranged
in a “wrap-around” structure. When powered on, tuner operation starts with the main menu that was last
used. Within each main menu, press the [MODE] button briefly to view the next main menu. Press and
hold the [MODE] button for two seconds to enter the setup mode (see below). Various tuner indicators
are shown on all four main menus: Antenna 1/2, IntelliTuneTM, Memory, Power Level, LC Limit, Meter
Range, Auto/Semi, and StickyTuneTM. Refer to Figures 11 and 12 for details on the displayed
information.
Note: In sideband mode, the frequency readout on the tuner display jumps around to different
frequencies while transmitting and stops on another frequency when un-keyed. This is
normal and is a characteristic of sideband mode, because sideband signals jump up and
down in frequency and power.
Note: In bypass mode, the decimal point in the SWR reading is replaced with a comma.
Digital Wattmeter Menu
Shows the frequency, SWR, and forward and reflected power in watts.
Power Bar Meter Menu
Shows the frequency, SWR, forward power, and bar meters for forward and reflected power. The top bar
meter is the forward power and the bottom bar meter is the reflected power. The numeric reading of
forward power appears at the end of the bar meters. A power scale is printed just below the display on the
front panel. Each power bar meter is consisted of 60 bar segments. When in the high power range, each
vertical bar segment consists of three dots. Below 100 watts, each bar segment represents two watts;
above 100 watts, each bar segment represents 20 watts. The forward bar meter has a “peak hold” feature.
The peak meter hold function freezes the highest displayed bar segment of the forward power for about
one second, so that you can more easily read the meter. This function can be turned ON and OFF in the
Peak Hold setup mode.
For low-power tuning, meter range of 30 watts is available. When in the low power range, divide the
readings on the printed power scale by ten and each vertical bar segment consists of two dots. Below 10
watts, each bar segment represents 0.2 watt; above 10 watts, each bar segment represents two watts.
Refer to the “SWR/Wattmeter” section on page 10 for more details on power range.
The power meter can be set to auto range. Auto range automatically sets the meter scale according to the
input RF power to the tuner. Forward power greater than 30 watts or reflected power greater than six
watts automatically sets the meter to the high power range. Forward power less than 25 watts and
reflected power less than four watts automatically set the meter to the low power range. When auto range
is enabled, a two-dot vertical segment appears on the on-screen tuner indicator. Refer to Figures 11 and
12 for the on-screen Range indicator.

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
12
0 255075100
PWR 300
Figure 8. Power Bar Meter (High Range).
0 255075100
PWR 300
Divide scale
by 10
Figure 9. Power Bar Meter (Low Range).
SWR Bar Meter Menu
Shows the frequency, SWR, forward power, and SWR bar meter. A SWR scale is printed just below the
display on the front panel. The 13-block (36-segment) SWR bar meter indicates SWR of 1.0, 1.1, 1.2,
1.3, 1.4, 1.5, 1.6-1.7, 1.8-2.0, 2.1-2.5, 2.6-3.0, 3.1-5.0, 5.1-15.0, and 15.1 to infinity. The numeric reading
of forward power appears at the end of the bar meter. There is also an audio SWR indicator (see “SWR
Beep Menu” section on page 17).
11.2 1.5 23
SWR
Figure 10. SWR Bar Meter.
L-Network Menu
Shows the configuration of the L-network matching circuit, SWR, and forward power. The antenna
symbol, on the upper left corner, indicates the antenna side of the L-network. The capacitance value is
displayed to the left when it is on the antenna side and to the right when on the transmitter side.
Inductance value is shown in microhenries (μH) and capacitance value in picofarads (pF). The numeric
reading of forward power appears at the lower right corner of the display. See “Manual Tuning” on page
18.

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
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Frequency
Indicators: Antenna, IntelliTune
Indicators:
SWR
Forward power in watts
Reflected power in watts
Forward power bar meter
Reflected power bar meter
SWR bar meter
A
ntenna symbol (antenna side of L-network)
Inductance value
Capacitance value when on antenna side
Capacitance value when on transmitter side
Memory, Power Level, LC Limit, Range
Indicators:Auto/Semi, StickyTune
1
2
3
4
5
6
7
8
9
10
11
12
13
14
6 7
1 2 3 4 5
8
9
1 2 3 4 5
6
10
1 2 3 4 5
6
11 12
13 14 6
2 3 4 5
Figure 11. Main Mode Menus Display.
Tuner Indicators
Various tuner indicators are shown on the main menus to indicate tuner status. Refer to Figure 11 for
locations of these indicators. The number enclosed within ( ) is the item number of Figure 12.
• Antenna: A small “1” appears to indicate antenna 1 is selected (15); a small “2” appears to indicate
antenna 2 is selected (16).
• IntelliTune: When IntelliTuneTM is ON, a bar appears on top of the Antenna indicator (17).
• Memory: A small “A”, “B”, “C” or “D” appears to indicator the selected memory bank when
Memory is ON (18-21).
• Power Level: When 150-watt power level is selected, a bar appears on the upper-left corner of the
Memory indicator (22).

MFJ-993B IntelliTuner Automatic Antenna Tuner Instruction Manual
©2003-2005 MFJ Enterprises, Inc.
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• LC Limit: When LC Limit is OFF, a bar appears on the upper-right corner of the Memory indicator
(23).
• Meter Range: When Auto Range is ON, a two-dot vertical bar segment appears on the lower right
corner of the Memory indicator (24), another dot appears on top of this bar segment when the meter
range is high, and no dot when the meter range is low (25).
• Auto/Semi: A small “S” appears to indicate semi-automatic mode; nothing appears to indicate
automatic mode (26).
• StickyTune: When StickyTuneTM is ON, a bar appears on top of the Auto/Semi indicator (27).
2 2
4
3
3 3
3
Enlarged Views of Indicators
Appears when
Appears when Antenna 2 is selected
Appears when IntelliTune is ON
Appears when Memory Bank A is ON
Appears when Memory Bank B is ON
Appears when Memory Bank C is ON
Appears when Memory Bank D is ON
A
ppears when in 150-Watt Power Level
Appears when LC Limit is OFF
Appears when Auto Range is ON
Appears when in (Auto) High Range
Appears when in Semi-Auto mode
Appears when StickyTune is ON
Antenna 1 is selected
16
17
18
19
20
21
15
25
22
23
24
26
27
15
17
16
17
20
22 23
24
25 21
22 23
24
25
18
22 23
24
25 19
22 23
24
25
26
27
Figure 12. Tuner Indicators.