
MFJ-939 Plug&Play IntelliTuner Automatic Antenna Tuner
Instruction Manual
2006-2015 MFJ Enterprises, Inc.
12
Pin 1 (Ground) connects to pin of Radio Interface Plug.
Pin 2 (TT) connects to pin 6 of Radio Interface Plu
Pin (Ground) connects to pin 5 of Radio Interface Plug.
Pin 5 (TS) connects to pin 8 of Radio Interface Plug.
g.
3
Pin 4 is not connected.
Pin 6 (+13.8V) connects to pins 2 and 3 of Radio Interface Plug.
4
1
3
2
4
6
5
Kenwood
Rear Panel View
1
2
3
4
5
6
Figure 8 Kenwood Interface Cable
1. Turn the tuner off. Set jumper JP2 to the “K” position.
2. Make sure jumper JP4 inside the MFJ-939 is installed.
3. Insert the 8-pin modular plug into the tuner’s RADIO INTERFACE jack.
4. 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.
5. Connect the 6-pin Molex connector to the mating 6-pin Molex connector, marked as AT or ACC,
on the back of the Kenwood radio.
1.
Push the [POWER] button on the tuner to the
in
position and then power on the radio.
2.
Some Kenwood radios automatically check to see if an external antenna tuner is connected during
power on. For other Kenwood radios, such as the TS-450S and the TS-690S, the External
Antenna Tuner menu in the radio menu system must be enabled. Refer to your radio’s operating
manual for accessing the menu system and preparing the AT-300 external antenna tuner
operation. Use TS-450S and TS-690S as an example:
a. Press and hold the [ENT] key while turning the power on.
b. Rotate the [M.CH/VFO CH] control to select menu number 01 on the display.
c. Press the [UP] or [DOWN] key to change the setting to “ON.”
d. Press the [CLR] key to return to normal operation.