MFJ-259C Instruction Manual
HF/VHF SWR Analyzer
5
3.) Frequency Counter Input
: BNC connector used for frequency-counter functions only.
3.2
Power-up Display
After turning on the
Power
switch (or after applying external power with the switch on), a sequence of three message
screens appear on the display.
The first screen presents the analyzer's software version (
VER)
.
The second message shows the software copyright symbol.
The third message provides a power-source check, displaying the internal battery or external power supply voltage
level along with a warning if the source is too low to support reliable operation.
The fourth and final power-up display is the
working screen
for the analyzer’s default operating mode, as described
in Section 3.2 (
SWR, Impedance R&X
). The two analog panel meters also become active, displaying
SWR
and
Impedance Magnitude
(Z)
measurements for the DUT.
The MFJ-259D has five (5) Basic Operating Modes that are used for conducting a variety of measurements. If you
tap (momentarily press) the
Mode
button, the analyzer steps to the next
Mode
selection. The five main modes and
their opening screens are described in Section-3.3 below:
3.3
Main MODE descriptions
Press the
Mode
switch to scroll through the analyzer's five operating modes. By "scrolling", we mean that each tap of
the mode switch will step the analyzer ahead to the next menu selection. Each new selection comes up on the display
with an
Identifier Screen
. After 3 seconds, the
Identifier Screen
is replaced by the mode's working screen. The menu
is circular, so after sequencing through all five choices, the sequence starts over. The five basic operating modes are
described in detail below:
1.) Impedance R&X (Initial Mode):
Use this mode for measuring SWR and complex impedance. The
Impedance
R&X
mode is the analyzers "default" mode because it is the one most frequently used for routine antenna
adjustments. The top line of the working display shows the
VFO Frequency
in MHz and the numerical
SWR
reading. The lower line displays the
Resistive
(R)
and
Reactive
(X)
impedance components for the attached load.
Pressing and holding the
Gate
button in this mode displays the
Impedance Magnitude
(Z) and
Phase Angle (Ø).
The analog
Impedance
meter also displays
Impedance Magnitude
(Z)
, and the
SWR
meter displays
Standing
Wave Ratio
(
SWR
). The analog meters are especially useful when tuning continuously adjustable circuits such as
an ATU or matching networks. The identifier screen for the
Impedance R & X
mode is shown below:
2.) Coax Loss
: Use the analyzer's second mode to measure loss incurred in random lengths of 50-Ohm cable, 50-
Ohm attenuator pads, 50-Ohm transformers, and 50-Ohm baluns. The top working-display line shows the
VFO
Frequency
in MHz and the lower line presents the measured
Loss
in dB.
Note that the transmission line or
device under test must be unterminated at its far end during loss testing. If a load or resistive termination is
MFJ-259C
VER 13.40
MFJ-Enterprises
(c)