MFJ-993B IntelliTuner Automatic Antenna Tuner
Instruction Manual
2005-2012 MFJ Enterprises, Inc.
20
SWR Beep Menu
Turns the audio SWR meter on and off. The audio meter is a series of beeps where one beep indicates
SWR of 1.5 or less, two beeps indicate SWR of 1.6 to 2.0, three beeps indicate SWR of 2.1 to 2.5, and
four beeps indicate SWR of 2.6 to 3.0. For SWR above 3.0, “SWR” (di-di-dit di-dah-dah di-dah-dit) will
be sent on CW. This functions independent of the acknowledgement beep setting. Default is OFF.
Shortcut:
Press both [L-UP] and [L-DN] buttons simultaneously to toggle SWR Beep on and off.
Beep Menu
Acknowledgement beep sounds each time a parameter is changed to acknowledge it. This also controls
the CW notification of “QRO”, “QRP” and “QRT”. This function can be turned OFF for silent operation,
and this is independent of the SWR beep setting. Default is ON.
Refresh Menu
When the refresh function is ON, the display is updated while tuning is in progress. Default is OFF.
Note:
Refresh slows tuning progress as it takes time to update the display.
Power-On Reset (POR) Sticky Tune Menu
Determines the state of
StickyTune
TM
when power is cycled. Default is OFF. If ON, then
StickyTune
TM
will be active for the first tune only. Then it will turn off.
StickyTune
TM
can be enabled by cycling power
with POR Sticky Tune set to ON or by pressing [TUNE] for more than two seconds.
LC Limit Menu
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. This setting is not stored in non-
volatile memory and reverts back to the default when the tuner power is turned off. Refer to Figures 13
and 14 for the on-screen LC Limit indicator. Default is ON.
Note:
If this feature is turned OFF, it will be re-set to ON whenever power is cycled.
WARNING:
LC Limit is a safety precaution; the tuner is in danger of being damaged if this
function is turned off.
