PSK - 31

PSK-31 is a digital mode that uses the sound card on your computer. It has very narrow band width so many signals can occupy 1- SSB channel. You will need an TNC (terminal node controller – sound card interface type), a computer, and software. There are several software packages that are free.

Terminal Node Controller The sound card terminal node controllers interface the Speaker, Microphone, and PTT of your transceiver to your computer. There are several manufacturers that make sound card TNCs, the main ones are Tigertronics, MFJ, and West Mountain Radio. The TNC can connect to your radio via a data port, or directly with the speaker and microphone.

Terminal Node Controller cont’d One of the main problems is the PTT (Push-To- Talk) arrangement. Most require a serial port, this is a problem in that most radios don’t have serial ports anymore. The Tigertronics has a built-in PTT circuit so no PTT from your computer is needed. The TNC interfaces with you sound card.

Terminal Node Controller cont’d Several of the newer TNCs have built-in sound card and passes the decoded signal to the computer via a USB cord. Some come with USB for keying. Some of the TNCs will require you to make cables to connect to the mike, PTT, and speaker. If the TNC uses a Data Port, no other connections to the transceiver is required.

West Mountain Radio – Rigblaster Interface to the microphone and speaker, serial cable for PTT, interface with the computer via sound card (microphone and speaker) and serial port for PTT Need to order per microphone connector type

MFJ -1273B Interface with microphone and speaker, PTT via serial port, interface with the computer via sound card (microphone, speaker) and serial port (for PTT)

Tigertronics – SL1+ USB Interfaces via radio data port, built-in sound card – interface to computer via USB

WB5CXC PSK-31 Configuration

Software You will need to get some software for decoding the PSK-31 signals. – Digipan – Fldigi – cocoaModem (for the Mac) The above are predominate freeware programs in use, there are also several paid programs that you can purchase.

Software cont’d Most of the software will have several modes, CW, RTTY, FAX, and others. The software needs to have macros, waterfall displays, and decode on multiple stations at the same time.

Recv Area 2 Recv Area 1 Transmit Area Waterfall Macros Mode

cocoaModem cocoaModem is a soundcard program for the Mac – it is similar to other soundcard programs. The Waterfall is a display of audio frequency vs time. Audio frequency (1 side band 300 – 3000) across, and time is up & down (in this case the current time is at the bottom of the display – some programs it is at the top).

cocoaModem cont’d Clicking on a signal (Green Line) will start the decoding down in Recv 1 area. The frequency is read out (you will transmit on this frequency). The frequency and a magnified waterfall is on the right side. Most all the newer programs have multiple station decodes. (cocoaModem calls it TableView)

Frequency Conversation Table View – Multiple stations decoded

Callsign Name

cocoaModem cont’d Highlighting a Callsign or Name and hitting special keys will put the in the boxes at the bottom. You can then use them in macros etc. You make macros for common exchanges etc. You usually begin each macro with transmit and end with receive commands. Macros use special character strings to denote items to use (callsign, name, my callsign, etc.)

Macros – name - script

cocoaModem cont’d The special string is proceeded by % sign. %(tx) is a command to key the transmitter, & %(rx) puts the transceiver in receive. %C other station’s callsign, %c your callsign, %H other station’s name, %h you name Macro are very useful for DXing & Contesting You go a whole QSO and never type anything just by using macros

Special Characters Items used in contest etc.

Macro – transmitted text

Adjusting Transmitter Use ~ full output power Send a signal – adjust the Tx level so it is just under the ALC (increase it until you see an ALC movement – then back off) You should be running ~ ½ power output Do not increase the level as it will start to splatter and give bad IMD (it is easier to copy a clean signal – if it is real bad nobody will talk to you).

Over Modulated Signal Water Fall Display Now +3 minutes Good PSK-31 Signal Weak Signal

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