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download digipan manual pdfUsing Digipan
A presentation on using Digipan software to pass
messages and hold QSOs with other operators.
Part of a continuing program of training presented by
Hernando County Amateur Radio Emergency Services.
With so many programs that operate Phase Shift Keying (PSK), one might ask why
One obvious reason is that it has been around for quite a while and is a very stable
program which is important when you want software that you must depend on.
The next benefit to Digipan is that this program will work on new PCs and older
equipment with limited memory and it is well suited for sending text under less than
desirable conditions. The program (version 2.0) can display more than one
conversation at a time which can be very useful when there is a need to monitor a
number of incoming signals.
It is known to work on an old 233 Mhz Laptop with 64 megabytes of memory
running under Windows 98 SE. The recommended system for use is a computer
with a 266 Mhz processing speed with Windows 95 or greater.
Digipan can also operate under the Linux operating system. This has been verified
using Ubuntu Linux version 8.04 using the Wine Emulator version 1.0. (Transmit and
Waterfall settings must be set using the native sound controls as they do not
function inside of Digipan when used under Linux.)
PSK can be used on HF, VHF, and UHF frequencies, modulated with AM, FM, or
SSB, and it is implemented with very little hardware other than a radio, a method to
connect the radio to a computer, and the software to send and receive with.
A more in depth discussion on this will follow later under the topic of Hardware
A Short explanation of PSK
Phaseshift keying (PSK) is a digital modulation scheme that conveys data by
changing, or modulating, the phase of a reference signal (the carrier wave). There
are three major classes of digital modulation techniques used for transmission of
digitally represented data:
* Amplitudeshift keying (ASK) on off keying such as that used to send Morse
* Frequencyshift keying (FSK) varies frequency to represent ones and zeros. An
example would be its use in a telephone modem.
* Phaseshift keying (PSK) – varies the carrier wave signal to represent ones and
zeros. There are several versions of PSK and a portion of those will be discussed
( A benefit to using PSK is the ability for a signal to be sent at lower power levels
than phone (voice) to go the same distance and it is much less susceptible to
interference from close stations. Multiple conversations or text data can be sent on
very close frequencies at the same time without loss of information. )
All shift keyed signals convey data by changing some part of a base signal in
response to a data signal. In the case of PSK, the phase of the carrier wave is
changed to represent the data signal. There are two basic ways of using the phase
of a signal:
* By viewing the phase itself as carrying the information, in which case the
demodulator must have a reference, or clock signal to compare the received signal's
phase against; or
* By viewing the change in the phase as carrying information — differential
schemes, some of which do not need a reference carrier (to a certain extent).
Digipan can use three variants of PSK which are well adapted to amateur radio
Binary Phase Shift Keying (BPSK) is a modulation technique that has proven to be
very effective for use on the amateur radio bands.
One form of this, known as PSK31, uses a small bandwidth of 31 Hertz to convey
information. The coding, called Varicode, is similar to ASCII used in radio teletype
(RTTY) excepting that loss of data synchronization is much less likely to occur with
Another form of BPSK is PSK63 which uses an increased bandwidth of 63 Hertz
to increase the speed of data sent. The third type is Quadrature phaseshift keying
(QPSK). Sometimes this is known as quaternary PSK, quadriphase PSK, 4PSK, or
4QAM. QPSK uses four phases which are used to encode two bits per symbol,
doubling the speed of data sent using the same band width as PSK31. This also
reduces the bit error rate (BER) — sometimes misperceived as twice the bit error
rate of BPSK.
A BPSK signal as shown on a
A QPSK signal as shown on a
As you can see QPSK can send more information in the same amount of time,
over the use of BPSK, although it does not seem to be used in preference over
PSK31, PSK63, and QPSK are all available for you to use, with the Digipan
As of the year 2010, PSK31 seems to be the preferred method of sending text data
It does not matter which mode you choose for sending data as long as there is
someone on the other end to receive it. There are enough subtle differences audibly