MFJ 1204 Instruction Manual

USB Radio Interface

Model MFJ-1204

CAUTION: Read All Instructions Before Operating Equipment

MFJ ENTERPRISES, INC.

Tel: [phone] Fax: [phone]

VERSION 2A

INSTRUCTION MANUAL

300 Industrial Park Road

Starkville, MS 39759 USA

COPYRIGHT 2017 MFJ ENTE RPRISES, INC.

MFJ-1204 USB Radio Interface User Manual

Introduction: The MFJ-1204 puts you in touch with Ham Radio's digital
revolution without complex wiring or setup procedures. In fact, the MFJ-1204 is
easier to set up and use than any other USB-interface on the market. All you
need is an existing radio, a computer, some free downloadable software, and
your MFJ-1204.

MFJ-1204 Features:

[ ] Full USB connectivity
[ ] Powered by USB port, no power adapter needed.
[ ] Dedicated on-board sound card
[ ] Quick plug-and-play Windows connectivity
[ ] Only two adjustable controls to operate
[ ] Works with all digital modes
[ ] Dozens of free downloadable programs available
[ ] Innovative PTT detector circuitry eliminates tricky VOX delay adjustments
[ ] Order "plug-and-play" for your radio -- no jumpers to set or connectors to wire
[ ] Order separate cables to use your MFJ-1204 with other radios
[ ] Perfect for base station, portable, or go-kit emergency operation

Connecting to your Radio: When you order the MFJ-1204 and specify a
particular radio, it will come with all interface jumper wires pre-installed along with
the correct interface cable and connector. The MFJ-1204 part number suffix
specifies which configuration is the right choice for your transceiver (see the
following table on the next page):

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MFJ-1204 USB Radio Interface User Manual

MFJ-1204

With Cable

Included

MFJ-1204P4 MFJ-5704P 4-pin round Mic connector

MFJ-1204P8

MFJ-1204J11 MFJ-5711J RJ-11 6-pin modular connector Any with RJ-11 Mic jack G
MFJ-1204J45 MFJ-5745J RJ-45 8-pin modular connector IC-706 (Mic port) B

Cable Only

Part

Number

MFJ-5708P

Cable Termination Radio

8-pin round Mic connector

Any with 4-pin connector

IC-728, 735, 738, 746-pro, 751

756-Pro, 761, 765, 775, 781

Jumper

Dia.

P

A

MFJ-1204D5 MFJ-5705D 5-pin DIN, TenTec Data/Acc

MFJ-1204D8 MFJ-5708D 8-pin DIN (Data/Acc) Any with 8-pin DIN port

MFJ-1204D13I

MFJ-1204D13K1 MFJ-5713DK1

MFJ-1204D13K2 MFJ5713DK2 13-pin DIN, Kenwood Data/Acc

MFJ-1204D13K3 MFJ-5713DK3

MFJ-1204MD6 MFJ-5706MD 6-pin mini-DIN, Yaesu, Icom

MFJ-1204K3
MFJ-1204KX3

MFJ-1204K MFJ-5700K Baofeng, Wouxun, Kenwood HTs
MFJ-1204R

MFJ-1204UT MFJ-5700UT

MFJ-5713DI 13-pin DIN, Icom Data/Acc

13-pin DIN, Kenwood Data/Acc

13-pin DIN, Kenwood Data/Acc

MFJ-5700K3

MFJ-5700KX3

MFJ-5700R

Elecraft Audio I/O and PTT jacks Elecraft K3 I
Elecraft KX3 Mic, phone jacks

Yaesu HTs

Unterminated

Argo-V, Jupiter, Omni-VII

Pegasis

IC-706, 716, 7000, 7200, 7300

7410, 9100

TS-140, 450S, 850, 870, 950

570D, 590S, 660, 2000

TS-440, 690

TS-940 E3

FT-100, 817, 687, 897, 950, 991

IC-706, 746, 7000, 7400

Any with 6-pin mini-DIN Data

Elecraft KX3

Chinese HTs, UV-5R etc

Yaesu, FT-50R, VX-8GR

No connector, no jumpers

installed

F

M

D

E1

E2

C

H

K

L

J

If you own an Icom 746-Pro, you would purchase the MFJ-1204 model with a P8
suffix. This package provides everything you need to start operating right away.

Changing Radios: Suppose, at some future time, you sell your IC-746-Pro and
acquire a new Icom-7300. You can transfer the MFJ-1204 to your new radio
simply by checking the chart, ordering a MFJ-5713DI cable, and changing the
jumper configuration to mirror Diagram D.

Connecting to the Computer: Once you're patched in to your radio, you can
connect the MFJ-1204 USB signal cable to any free USB port on your PC to
obtain power and establish a two-way signal path. Your computer should be
turned on and booted up before this connection is made.

Important Note: Do not connect the MFJ-1204 to your computer until the
prescribed set of jumper wires are installed, the computer is turned on,
and its operating system has fully booted up. Also, close any applications
that are open and running before plugging in the interface.

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MFJ-1204 USB Radio Interface User Manual

When you plug in the USB interface cable, the computer will signal that one or
more new devices have been connected. The interface sound card will then
automatically begin loading the following drivers:

USB Composite Device
USB PnP Sound Device
USB Human Interface Device

Installation typically takes less than a minute to complete. After the drivers have
loaded, select Restart and reboot you pc before continuing.

Important Warning: If you don't restart before continuing, some Windows
operating systems (such as Vista) may hang up. Always restart right after
installing.

Choosing a USB Port: Driver installation is a one-time event for each USB port
you select. If you change USB ports, the soundcard will repeat the setup

sequence and you'll need to restart again. It's generally more convenient to
delegate one specific USB port to your MFJ-1204 and stick with it.

Communication Modes: The MFJ-1204 supports virtually every data and
digital-voice mode in use today. With the appropriate software downloads, you
can transmit and receive traditional modes such as CW, RTTY, SSTV, AMTOR,
PSK31, and EchoLink. Or, you can explore newer modes like MT-63, WINMOR,
WSPR, and WSJT-X. If your radio can pass the signal and your computer can
run the downloaded communication program, the MFJ-1204's built-in sound card
and your PC should handle the rest!

Selecting a Download Program: Literally dozens of downloadable shareware
communication programs are available. Many are quite inclusive, offering a
selection of several modes, while others are highly specialized. It's also true that
some simply work better than others. While MFJ doesn't endorse or recommend
any particular program, many operators say HamScope is well established and
covers several popular communication modes, so it might be a good place to
start your exploration into the world of digital radio.

Selecting the USB Soundcard: Most communication programs will require you
to select a sound card as part of their setup procedure. Select USB Sound. This
choice directs your computer to access the sound card built into the MFJ-1204
rather than the resident card installed in your computer.

Receive Audio Level: The MFJ-1204 Receive Audio control is uncritical and
relatively easy to set up. When copying signals off-air, simply adjust for the most
reliable on-screen display of the incoming signal. If your receiver has built-in
audio EQ, set it for flat frequency response (±0 dB) for best results. Also, be sure

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