INTRODUCTION ................................................................................3
THEORY OF OPERATION.................................................................3
MFJ-226 Technical Specifications ......................................................4
LAYOUT AND CONTROLS ................................................................5
1. Analyzer Test Port:.................................................................5
2. USB Data Port:.......................................................................5
4. Boot Key: ................................................................................5
5. Arrows (up/down): ..................................................................5
6. Enter Key:...............................................................................5
7. Return (Exit): ..........................................................................5
8. Mode ......................................................................................5
9. Battery Door ...........................................................................5
10. Numerical Keypad: ...............................................................5
POWERING THE MFJ-226.................................................................6
MENU STRUCTURE ..........................................................................6
USING THE SETTINGS MODE .....................................................6
1. Backlight:................................................................................7
2. Auto Power Off: ......................................................................7
3. Battery Menu: .........................................................................7
4. Step Size Unit:........................................................................7
5. LCD Contrast:.........................................................................7
6. Cal Data Protect: ....................................................................7
7. System Information ................................................................7
ENTERING SINGLE-FREQUENCY MODE .......................................8
SETTING THE DDS OPERATING FREQUENCY .........................8
Direct DDS Entry: .......................................................................8
Scroll/Step Entry:........................................................................8
SINGLE-FREQUENCY MENU .......................................................8
Screen 2, ....................................................................................9
Screen 3 .....................................................................................9
Screen 4 .....................................................................................9
ENTERING SWEPT FREQUENCY MODE ......................................10
General Screen Layout: ...........................................................10
SWEPT-FREQUENCY SETUP ....................................................10
Start Frequency: .......................................................................10
Stop Frequency: .......................................................................10
Y Scale: ....................................................................................11
Calibrate: ..................................................................................11
Load Cal Data: .........................................................................11
SAVING TEST DATA ....................................................................11
Save File: .................................................................................11
Grid:..........................................................................................11
SWEPT DATA SCREENS.............................................................12
SWR Screen:............................................................................12
Impedance Magnitude Screen (Z):...........................................12
Resistance Screen (R): ............................................................12
Reactance Screen (+X or -X): ..................................................13
Return Loss (S11): ...................................................................13
Phase Angle (Deg): ..................................................................13
Smith Chart Screen: .................................................................14
CALIBRATION ..................................................................................14
Global Calibration File ..................................................................15
Building a Local Calibration File ...................................................15
Executing Global Calibration ........................................................16
CALIBRATION LOAD SET ...............................................................17
USING YOUR PC TO COMMAND THE ANALYZER.......................18
Computer Software Control ..........................................................18
Manual Control via Computer.......................................................18
FIRMWARE UPDATE PROCEDURE.................................................2
12 MONTH LIMITED WARRANTY.....................................................3
Important Note: Before turning on your analyzer for the
first time, we strongly recommend reading through the
entire manual. You will find valuable operating information
along with important tips to help you take full advantage
its full range of features.
The MFJ-226 is accurately calibrated at the factory and
should not need recalibration for initial use.
Do not run CALIBRATE with out proper calibration loads.
The display window has a plastic film applied at the
factory to protect the display window from scratches in the
manufacturing process. This film can be removed if
desired.
MFJ-226 Graphical Antenna Impedance Analyzer
INTRODUCTION
The MFJ-226 is part of the Times Technology Series of analyzers and
is a compact single-port Vector Network Analyzer (VNA) that
characterizes complex RF loads in 50-Ohm systems with a high
degree of accuracy. Packaged for portable use, it's easy to operate
under a wide range of test conditions yet delivers many advanced
features usually reserved for units costing much more. For example:
MFJ-226 can compensate for phase rotation and losses in
feedlines and test cables by using industry-standard
Open/Short/Load (OSL) calibration setups.
MFJ-226 calculates true reactance sign (plus or minus),
eliminating sign ambiguity.
The DDS stimulus generator provides continuous coverage
from 1 MHz to 230 MHz.
The DDS accepts both step-tuning and direct-frequency entry
via keypad.
The DDS features 1-Hz frequency resolution with rock-solid
stability
There are 32 memory files for capturing and downloading test
data to a PC.
MFJ-226 has extremely simple power requirements (two AA
batteries, Alkaline or NiMH).
All test results are displayed on a bright easy-to-read backlit
LCD display.
The deluxe backlit keypad has large positive-action keys for
easy field operation.
The thick-wall molded case is hand-contoured and rugged.
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MFJ-226 Graphical Antenna Impedance Analyzer
Whether you are putting up a simple dipole, building a complex
matching network, or characterizing an unknown device, the MFJ-226
delivers the type of data you need to get the job done. A user-friendly
menu system provides rapid access to all operating modes and
features:
Single-Frequency Mode: Presents SWR, Complex
Impedance (series and parallel), and S11 scattering
parameters (rectangular and polar). SWR is displayed in
huge inch-high numbers clearly visible from several feet
away.
Sweep-Frequency Mode: Graphically plots SWR,
Impedance Magnitude (Z), Resistance (R), Reactance (X),
Return Loss (RL, S11), Phase Angle, and Smith Chart
displays. A continuously tunable frequency marker pulls up
precise alpha-numeric data.
Calibrate Mode: Walks you through the OSL cal setups for
both specific swept frequency measurements and for the
unit's global calibration procedure.
Settings Mode: Offers useful options, shows battery
condition and firmware revision.
PC-Mode: Links the analyzer’s memory files to your PC
through the serial data port.
THEORY OF OPERATION
The MFJ-226 is a full-featured one-port Vector Network Analyzer
(VNA). The term "vector" means it analyzes both the amplitude and
phase angle of reflections returning from loads being tested in order
to present complex impedance data.
Test Connector
Stimulus
Generator
LCD
Display
PC Port
Microprocessor
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Directional
Coupler
Load
(DUT)
MFJ-226 Graphical Antenna Impedance Analyzer
As shown in the diagram above, the analyzer's DDS RF-Stimulus
Generator (or VFO) generates a test signal that routes through the
directional coupler to the load under test. If a mismatch (impedance
discontinuity) exists, a portion of that generated signal is reflected
back to the load.
The Directional Coupler measures amplitude and phase of both the
forward and reflected signals and feeds that information to the
microprocessor.
The Microprocessor compares data from the coupler and
mathematically converts it to useful engineering parameters such as
SWR, complex impedance, and S11 coordinates.
Using the Keypad and Menu System, the operator can call up the
specific type of data needed for display on the LCD Screen.
The MFJ-226 is compact and simple to use, but offers several
advanced features that set it apart from may lower-cost analyzers.
These features include OSL (Open/Short/Load) calibration, true
reactance signs, continuous frequency coverage, exceptionally high
DDS resolution, extensive on-board memory, a serial data port, and
simple power requirements.
MFJ-226 Technical Specifications
Frequency Range: Continuous, 1 MHz to 230 MHz
Frequency Resolution: 1 Hz
Test Port Termination Type-N Female
Output Power +10 dBm typical
Harmonics -15 dBc typical
LCD Display 128 x 64 resolution with backlight
Dimensions 6.5" (165 mm) x 3.12" (80 mm) x 1.25" (32
mm)
Weight 10 oz with batteries and UHF adapter
Power Two (2) AA cells, Alkaline or NiMH
Computer Interface USB serial
OSL Calibration Male-N or UHF, Open, Short, and 50-Ohm
Load
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MFJ-226 Graphical Antenna Impedance Analyzer
LAYOUT AND CONTROLS
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MFJ-226
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1. Analyzer Test Port: N-Female, accepts N-male for DUTs and
calibration loads.
2. USB Data Port: Accepts micro-USB connector, interface
with a PC for download. (Not for powering
the unit or charging batteries).
3. LCD Screen: Displays menu selections, plots, and test
data.
4. Boot Key: Boot key, press and hold to turn analyzer
on or off.
5. Arrows (up/down): Step or scroll for menu selections and
frequency tuning.
6. Enter Key: Enters menu selections and frequency
setups.
7. Return (Exit): Escapes from current function, returns to
previous function.
8. Mode: Sets decimal point for numerical entries,
serves multiple menu functions.
9. Battery Door: Located on back, accesses tray holding
two AA cells.
10. Numerical Keypad: 0-9 keys for entering frequencies or
numerical data.
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MFJ-226 Graphical Antenna Impedance Analyzer
POWERING THE MFJ-226
The MFJ-226 requires two (2) AA batteries. The battery tray door is
located on the back of the analyzer case near its base. Press and
slide the lid down to expose the tray.
You may use alkaline non-rechargeable or NiMH rechargeable cells.
Note that NiMH cells require an external charger (the analyzer does
not have one built-in). For longest life, use fresh premium-quality cells
from the same manufacturer. Carefully observe polarity during
installation and never remove batteries while the unit is powered up.
Abruptly cutting power can disrupt the unit's normal power-down cycle
and result in memory loss.
The MFJ-226 features a built-in battery indicator that must be set up
for the type of battery you intend to use. See the Settings Menu for
details.
Note the USB port does not power the MFJ-226 or charge batteries.
MENU STRUCTURE
The MFJ-226 features short circular menus that allow you to identify
and access all functions quickly and easily. The Main Menu and its
five Sub-Menus are shown below:
Main Menu
Single Freq
Sweep Freq (Plot) Calibrate (OSL) Settings PC Mode
SWR, Z SWR
Series Imp
Parallel Imp
S11
Impedance (Z)
Resistance (R)
Reactance (X)
Return Loss (S11)
Phase Angle
Smith Chart
All
Open
Short
Load
Backlight
Auto Power Off
Battery (Type)
Cal Data Protect
Info (System)
Host
USING THE SETTINGS MODE
To check and change the analyzer's default settings, power up using
the Boot key. After a brief opening screen, the Main Menu will appear.
Using the Down-Arrow key, step to the Settings menu and press
Enter.
When the Settings menu opens, use the Up/Down keys to make
selections. To modify a setting, step to the desired option and press
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