MFJ MFK-5124Y - Introduction; Front Panel Overview

MFJ-5124K/Y Radio Interface Instruction Manual
© 2005-2010 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, FC-30 compatible Yaesu
transceivers, and certain Yaesu transceivers with supported 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 CAT. Using the appropriate cable
and selecting the interface protocol via internal jumpers allow one-button
automatic tuning operation with various Kenwood and Yaesu transceivers.
Front Panel
MFJ-5124 Radio Interface
POWER
TO RADIO
TO T UNER
• 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 provide +13.8 volts through the radio’s tuner port (Kenwood
AT/ACC or Yaesu CAT/LINEAR/TUNER) 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 CAT connector, 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/LINEAR/TUNER connector. Use
proper cable for the various radios.