PSK - 31
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-ToTalk) 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.
Mode
Waterfall
Recv Area 2
Recv Area 1
Transmit Area
Macros
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
Items used in contest etc.
Special Characters
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).
Water Fall Display
+3
minutes
Now
Weak
Signal
Good PSK-31
Signal
Over Modulated
Signal
Test
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Test
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Test
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Test
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