MFJ MFJ-993, Instruction Manual

Page: 10 / 36

MFJ-993 IntelliTuner Automatic Antenna Tuner Instruction Manual
©
2003-2004 MFJ Enterprises, Inc.
4
Front Panel
0
1
0
30
50
10
0
200 3
00
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-993
ANT C-UP L-UP AUTO POWER
MODE C-DN L-DN TUNE
LCD
SWR
VOL
Z
AUTOMATIC ANTENNA TUNER
300 Watts PEP SSB / 150 Watts CW
BYPASS 300 / 30
WATTS
MFJ IntelliTuner
TM
1 1.2 1.5 2 3 5 SWR
14.100 MHz 1.1
FWD=100 REF=0.5
AUTO RANGE
0 25 50 75 100
Pwr
300
Figure 2. MFJ-993 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 8 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 Figure 10 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.
•
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.