MFJ-998RT Legal Limit IntelliTuner
TM
Automatic Remote Antenna Tuner Instruction Manual
© 2011 MFJ Enterprises, Inc
MFJ-998RT Version 1A
5
Operation
1. Turn on the tuner power. With the power off the Tuner is in Bypass mode. With power on the unit
wakes up in bypass mode till RF is supplied to the tuner.
2. Initial Tuneup:
a. Transmit a low power signal (5 to 20 watts, never with the amplifier in transmit mode).
b. Wait while the tuner finds a tuning solution for that frequency. Verify that the SWR is
below the target SWR (default 1.5:1).
c. Once the tuner has found a tuning solution you are ready to operate at high power.
d. You can repeat the initial tune up on other frequencies and bands so the tuner will
memorize what setting are needed for these frequencies and bands.
e. If the solution is higher than you prefer but within the SWR window of the retune functions
turn off the tuner so it will go to bypass, turn it back on then after 2 seconds and try to
tune again.
3. Normal Tuneup
a. Transmit a low power signal (5 to 20 watts, never with the amplifier in transmit mode).
b. The tuner will check the frequency and set the tuner for the settings for that frequency if
memorized and quickly tune to those settings.
c. If the frequency is not memorized or the SWR is outside the tuning window then the tuner
will retune as in the initial tuneup.
4. Once the tuner is tuned up you can switch to high power operation.
5. Manual tuning is possible but is not available remotely. To tune manually you will have to remove
the cover and operate the controls as indicated in the section “MANUAL TUNING” on page 15.
Once a manual setting is found it can be saved for later retrieval as in the above step 3.
WARNING
Never tune up with high power.
Always use low power (5 to 20 watts) when tuning up or changing frequencies. Tuning with high power
will cause voltages and currents that may exceed the component ratings or present antenna loads that
will damage an amplifier or radio during the tuning process.
WARNING:
Do not turn the power on and off rapidly, otherwise the tuner setting memory can be corrupted and the
unit will have to be reset to factory defaults. Leave the tuner off for 1 to 2 seconds before turning it back
on.
Note: When attempting to tune the Tuner will not tune and go into bypass when the forward power
exceeds 75 watts and the SWR is greater than 3.0, or when the forward power exceeds 125 watts while
tuning regardless of the SWR. See “Morse Code and Beeps” Page 16
