MFJ-5124K/Y Radio Interface
Instruction Manual
©
2005 MFJ Enterprises, Inc.
1
Introduction
The MFJ-5124 Radio Interface main unit contains all the electronics that allows
users of AT-300 compatible Kenwood transceivers and certain Yaesu
transceivers with CAT system to connect to the MFJ-991, MFJ-993 and MFJ-
994
IntelliTuner™
Automatic Antenna Tuners. With this interface, DC power
to the radio interface and the tuner is supplied by the radio, except FT-847.
Uses of appropriate cable and selecting the interface protocol via internal
jumpers allow the interface to connect to the various Kenwood and Yaesu
radios. The radio interface allows one button tuning operation.
Front Panel
MFJ-5124
Radio Interface
POWER
TO RADIO
TO TUNER
•
To Tuner:
The 3.5 mm stereo phone plug connects to the tuner’s RADIO
INTERFACE jack, and the 2.1 × 5.5 mm coaxial plug connects to the
tuner’s POWER jack.
•
Power:
Accepts a standard 2.1 × 5.5 mm coaxial plug with positive center
and negative sleeve. The tuner requires 12 volts DC at up to 1 amp. The
use of a regulated supply is not mandatory but is recommended for best
performance. An optional 12 volts DC 1.5 amp power supply, the MFJ-
1316, is available from MFJ Enterprises, Inc.
Most radios p13.8 volts through the radio’s tuner port (Kenwood
AT/ACC and Yaesu CAT ports) to the TO RADIO jack, so the POWER
jack connection is rarely used. If the radio’s tuner port does not have a
power connection, such as the Yaesu FT-847, then connect a power supply
to this connector. If the radio’s tuner port has a power connection but
cannot supply one amp of current, then remove the internal jumper JP3 and
connect a power supply to this connector. Check your radio’s operating
manual.
WARNING:
Do not apply voltages greater than 18 volts to this
unit, or permanent damage to the unit and the tuner
may result.
•
To Radio:
Accepts an 8-pin modular plug that connects the radio interface
to a Kenwood AT/ACC or Yaesu CAT port. Use proper cable for the
various radios.
