MFJ IntelliTuner -991, Instruction Manual

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MFJ-991 / MFJ-994 IntelliTuner Automatic Antenna Tuners Instruction Manual
©
2004 MFJ Enterprises, Inc.
11
Component Limit
The upper limits of inductance (L) and capacitance (C) are factory-limited according to frequency and
maximum power rating; i.e., higher frequencies need less inductance and less capacitance when the L-
network is properly tuned. Pressing [C-UP] and/or [L-UP] allows capacitance and inductance to be
increased only to these limits. When a selected capacitance or inductance is higher than its allowed limit,
and the frequency is changed, that selection is automatically reduced to the value of its limit. These limits
are used to prevent matching of extreme load impedance outside the tuner’s specification, which may
result in excess voltage and/or current across the tuner’s components.
Antenna Memory
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. The memory resolutons 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 two 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. Antenna Memory Resolution.
The memory resolution for non-amateur frequency bands between 160 and 10 meters is approximately
one percent of the lower frequency of that band. There are more than one thousand antenna memory
locations.
To clear the antenna memory, turn off the power to the tuner, then press and hold both [TUNE] and [C-
DN] buttons while turning on the power. Both meter needles will read half scale, forming a triangle,
asking you to confirm the deletion. Press [C-UP] to confirm delete (both meter needles will read full
scale), or press [L-UP] to cancel the antenna memory delete (both meter needles will read zero).
“Total Reset” erases the antenna memory
and
returns all tuner settings to their factory default states. To
achieve this, turn power off, press and hold [TUNE], [L-DN] and [C-DN] buttons while turning on the
power. The meter needle readings will be the same as for antenna memory delete: half scale. Press [C-
UP] to confirm total reset (needles go to full scale) or press [L-UP] to cancel total reset (needles go to
zero).