Introduction - Using Multipsk Software as a TNC for JNOS (WIN32)

Using a soundcard in place of a hardware modem or tnc is an option that has gained alot of interest over the past few years. There are some good programs out there that let you use a soundcard for lots of different digital modes. One such program is Multipsk - written by Patrick, F6CTE. If you want some more general information on this program, click here. What is cool about Patrick's program is that it has a built-in tcp/ip server, allowing outside applications to connect to Multipsk, and use it as a digital modem.

JNOS can now be added to the list of programs that are able to directly connect to Multipsk and use it as an packet (ax25) modem. Patrick has added the ability to send KISS frames over the tcp/ip server.

Downloading Multipsk Software

You must use Multipsk version 4.13 or higher - earlier versions do not support KISS over tcp/ip server.

Click here to download.

Example Setup

JNOS (WIN32) and Multipsk are running on the SAME Windows 7 Pro machine.

In your autoexec.nos (or you can enter this at JNOS console) :

   attach  multipsk  vhf  3122

where '' is the IP ADDRESS of the windows PC (change to whatever you are using)

JNOS will try to connect to Multipsk once a minute - watch the JNOS log for this.

Once connected, the new 'vhf' port is just like any other AX25 port in JNOS.

Running Multipsk


- After starting the "Multipsk.EXE" file, you will find the "Configuration

- Click on the "TCP/IP server "On"" button to start automatically the TCP/IP

- Click on big button "RX/TX screen" to start the decoder (and authorize the
TCP/IP connection required by Windows),

- It is strongly recommended to calibrate the sound-card: click on the
"Adjustments" menu button, then select the "Determination of the RX/TX
sound-card sampling frequencies" option and push on the "Determination of
the 48 KHz RX sampling frequency (test on 3 minutes)" button. At the end of
the test, click on "Return",

- Click on the "PACKET+APRS" orange button,

- To use the TCP/IP possibility, click in the "Options" button which opens
the window "Packet parameters", then push the "KISS through TCP/IP" button
located in the "Miscellaneous" box. Click on "OK".

- Push the "KISS" button. That's all for Multipsk.

New Command Line Options you may find useful

  Patrick has added some additional commands that you might find helpful. He
  recently posted (27Feb2013) on multipsk yahoo list, from the manual:

    It is reminded that 3 possible parameters can be added on the Multipsk
    command line: TCP_IP_ON to switch the TCP/IP interface on, RX_TX_SCREEN to
    open the RX/TX screen and MINIMIZE to minimize the RX/TX screen (Multipsk
    appearing as an icone).

Note about the sound level ("Level" indication in % at the top of the
screen): an AF level superior or equal to 10 % is OK. About 50 % is ideal
(but not critical). In case of very low AF level, select "16 bits" in the
"Determination of the RX/TX sound-card sampling frequencies" option
("Adjustments" menu button),

About the help in Multipsk:

- To bring up the text help (contextual sensitive one), click on the right
button of the mouse, with the cursor over the mode button "KISS", for

- Also use the button hints (wait a fraction of second over a button).

73 de Maiko Langelaar, VE4KLM