MFJ-928 Compact IntelliTuner Automatic Antenna Tuner
Instruction Manual
©
2005 MFJ Enterprises, Inc.
6
Back Panel
RADIO
INTERFACE
+
POWER
12VDC
750mA
WIRE
MFJ ENTERPRISES, INC.
STARKVILLE, MS USA
GROUND
!
Do not connect
WIRE and
ANTENNA 1
at same time!
TRANSMITTER
ANTENNA 2
ANTENNA 1
Figure 4. MFJ-928 Back Panel.
•
Power:
This jack 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 750 milli-amps. 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.
WARNING: Do not apply voltages greater than 18 volts to this unit, or permanent damage
to the unit may result.
Note: When the tuner power is OFF, the tuner is in bypass mode and RF from the transmitter
goes directly to the antenna (ANTENNA 1) with no matching.
•
Radio Interface:
An 8-pin modular (RJ-45)
connector for connecting to the tuner interface
connector of compatible radios. Most radios
p13.8 VDC power thought its tuner
interface connector. If separate power
supplies are used to power the MFJ-928, the
MFJ-928 should be powered on first (both
LEDs blink once) and then turn on the radio,
so the radio knows an external tuner is
attached. The radio will disable its internal
tuner, if it has one, and use the external tuner.
The Radio Interface works with radios that are compatible with Alinco EDX-2, Icom AH-3 and AH-
4, Kenwood AT-300, and certain Yaesu radios with CAT system. When connected to a compatible
radio, simply press the [TUNER] or [AT] button on the radio; for certain Yaesu, press the [TUNE]
button
on the
tuner
to start the automatic tuning process. The radio will automatically switch to CW
mode (AM for Yaesu), transmit a 10-watt carrier, and start the tuning process. Once the automatic
tuning is completed, the radio will return to its previous mode and power setting.
+13.8 V DC input ( 50 mA)
+13.8 V DC input ( 50 mA)
+13.8 V DC input ( 50 mA)
Ground
Ground
Key/TT/TX
TX INH
Start/TS/RX
7
7
7
7
8
6
5
4
3
2
1
12345678
Rear Panel View
Figure 5. Radio Interface Connector.
Summary of Contents for Compact IntelliTuner MFJ-928
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