MFJ-993B IntelliTuner Automatic Antenna Tuner
Instruction Manual
©
2003-2005 MFJ Enterprises, Inc.
16
Shortcut:
Press both [TUNE] and [L-UP] buttons simultaneously to cycle the auto tune SWR
among 0.5, 1.0 and 1.5. Refer to Table 2 for meter code.
Meter Range Menu
Allows you to select the meter scale range. In the 30 watts (low) range, the forward full scale is 30 watts
and the reflected full scale is 6 watts (divide the meter reading by 10). In the 300 watts (high) range, the
forward full scale is 300 watts and the reflected full scale is 60 watts. 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. Refer to Figures 11 and 12 for the on-screen Meter Range indicators. Default is 300 watts
range.
Shortcut:
Press both [TUNE] and [L-DN] buttons simultaneously to cycle the meter range among
30 watts, 300 watts and auto range. Refer to Table 2 for meter code.
Peak Hold Menu
When the peak hold function is ON, the highest activated segment of the forward bar meter remains
visible for about one second, so that you can more easily read it. When OFF, the meter functions
normally. Default is ON.
Memory Menu
Turns the antenna memory on and off. The “memory resolution” is the width of frequency spectrum that
the tuner recognizes as being the same as a tuned frequency already in memory. The memory resolution
is approximately 0.1 percent of the lower frequency of each amateur band. For example, the memory
resolution on the 40-meter band (7000 to 7300 kHz) is 7 kHz; if the tuner has memorized a setting for
7050 kHz, it will automatically call up this setting for any frequency from 7047 to 7053 kHz. Memory
resolution is smaller at lower frequency to accommodate the higher antenna Q and larger at higher
frequency where the antenna Q is lower. The memory resolutions for the HF amateur bands 160 through
10 meters are:
Meter
Frequency Range (kHz)
Memory Resolution (kHz)
160
1800 – 2000
2
75/80
3500 – 4000
4
60
5330.5, 5346.5, 5366.5, 5371.5 and 5403.5
5 memory locations
40
7000 – 7300
7
30
10100 – 10150
10
20
14000 – 14350
14
17
18068 – 18168
18
15
21000 – 21450
21
12
24890 – 24990
25
10
28000 – 29700
28
Table 1. Memory Resolution.
The memory resolution for non-amateur frequency bands between 160 and 10 meters is approximately
0.2 percent of the lower frequency of that band. There are over 2500 memory locations for each memory
bank, and each antenna has four memory banks (A-D). Tuner settings are stored in memory separately