MFJ-5124K/Y Radio Interface Instruction Manual
©2005-2006 MFJ Enterprises, Inc. 5
Yaesu Radio TUNER Interface
The MFJ-5124Y radio interface allows users of Yaesu FT-100, FT-857, FT-897,
and FC-30 compatible Yaesu transceivers to connect to the MFJ-991, MFJ-993
and MFJ-994 IntelliTuner™ Automatic Antenna Tuners. With this interface,
DC power is supplied by the radio and control signals are connected between the
radio and the tuner. The operator can then control the tuner with a single push
of the (TUNE) key on the front panel of the radio. Supported Yaesu radios are
FT-100, FT-857, FT-897, and any Yaesu radio that supports the Yaesu FC-30.
Connections for FT-100
1. Before connecting the MFJ-5124 to your radio, follow the instructions
in the radio’s manual for installing the FC-20 automatic antenna tuner.
a. Press and hold in the [FUNC] key for ½ second to activate the
Menu mode.
b. Rotate the SELECT knob to recall Menu #61 [TUNER/ATAS],
and then rotate the MAIN DIAL to change the setting to “tunEr.”
c. Press the [FUNC] key momentarily to save the new setting and
exit to normal operation.
d. Turn the FT-100’s power off, then on again, to re-initialize the
radio regarding the tuner status.
2. Turn the radio off.
3. Insert the 3.5 mm stereo phone plug into the tuner’s RADIO
INTERFACE jack.
4. Insert the 2.1 x 5.5 mm coaxial power plug into the tuner’s POWER
jack.
5. Insert the 8-pin modular plug into the MFJ-5124’s TO RADIO jack.
6. Important:Make sure the DC power to the radio has been turned off.
The radio does not fuse the DC power to the tuner, and damage to the
radio can occur if the interface’s power connection comes in contact
with ground.
7. Connect the 8-pin mini DIN connector to the mating 8-pin mini DIN
connector at the end of the BAND DATA cable pigtail on the back of
the radio.
8. Push the [POWER] button on the tuner to the in position. When the
radio is turned on, the tuner will also power on.
MFJ-5124K/Y Radio Interface Instruction Manual
6 ©2005-2006 MFJ Enterprises, Inc.
Operation for FT-100
The operation of the MFJ-5124Y radio interface is similar to the operation of the
FC-20 described in the Yaesu radio’s operating manual.
1. Turn on the radio and press the [FUNC] key, as needed, to recall
Operating Function Row 7 [MTR, TUN, PRO, VOX].
2. Press the [B](TUN) key on the radio for ½ second to turn the FC-20
function on; the “TUN” indicator will appear bolded on the radio’s
display.
3. Press and hold in the [B](TUN) key on the radio to initiate automatic
tuning. The radio will automatically transmit a low-power carrier and
start the tuning process. When tuning is completed, the radio will stop
transmitting and you will be ready for operation on this frequency.
Press the [B](TUN) key again to cancel tuning in progress.
Note the [TUNE] button on the tuner will not operate the Yaesu radio’s TUNER
interface.
Connections for FT-857 or FT-897
1. Before connecting the MFJ-5124 to your radio, follow the instructions
in the radio’s manual for installing the FC-30 automatic antenna tuner.
For the following procedure, use the [FUNC] key and the SELECT
knob on the FT-857, or use the [F] key and the MEM/VFO CH knob on
the FT-897.
a. Press and hold in the [FUNC] or [F] key for one second to activate
the Menu mode.
b. Rotate the SELECT or MEM/VFO CH knob to recall Menu Mode
#001 [EXT MENU], and then rotate the DIAL to change the
setting to “ON” to enable the extended Menu Mode.
c. Rotate the SELECT or MEM/VFO CH knob to recall Menu Mode
#020 [CAT/LIN/TUN], and then rotate the DIAL to change the
setting to “TUNER.”
d. Press and hold in the [FUNC] or [F] key for one second to save the
new setting and exit to normal operation.
e. Turn the radio off, then on again. Do not connect the MFJ-5124Y
before changing the Menu Mode #020 [CAT/LIN/TUN].
f. Press and hold in the [FUNC] or [F] key for one second to activate
the Menu mode.