Ham & DSP
Related histories, facts and opinions by EA2BAJ
since 15 May 1998
(Last modified 9-Mar-1999)
I am a new Ham, I have recently (July-1996) get my CEPT-1 Class licence
after having owned the following Callsigns: EB2FUQ and EC2AGF. I am mainly
interested in digital modes, as I come from the computer environment. I
haven't still made a HF voice QSO.....
I am presently trying to learn as much as possible (very little time,
very little results) from digital modulation over radio. More especifically
using DSP evaluation cards from Texas and Motorola. At the moment I am
almost exclusively using them not programming, but I think that time will
DSP and HAM
The idea is to use a DSP to produce the modulation/demodulation (Modem)
part of a Multimode Controller. What does this mean? For example, if you
get a VHF 1200 packet modem, once you load the DSP with it you have the
equivalent of a TNC in kiss mode, you need a soft driver to get for example
a HOST interface and later a program that is able to talk to a HOST TNC.
So if you want to have a Mailbox running you need a computer running all
There are several advantages
The cost is
low (comparing to standard Multimode Controllers).
It is easy to
upgrade the software (no EPROMS to burn).
There is much
software available with sources.
There are many
modems available: VHF packet 1200/9600, HF packet 300, 1200 BPSK, AMTOR,
There are many
sound processing soft: CW/SSB Filters, autocorrelation filters, automatic
There are also disadvantages
If you don't
program (as me) you are bound to the authors that kindly developed a modem
to keep it working (mainly if he didn't release source code)
If you plane
to employ unattended operation, you need to have a computer running all
the time: Noise...
You must search
a program available to your OS of choice...
must use a computer to load soft on the board.
What to use / Where
There is a place
to begin searching about DSP and HAM, it is at Tuckson Amateur Packet Radio
can take a look at it, or go directly to Digital
Signal Processing Experimenter's Page. What follows is facts about
the DSP Evaluation modules I have used. There are also applications on
other DSP, but I haven't tried them.
One of the most
advanced DSP used by Ham is the Motorola
56002 which is available in a low cost Evaluation Module named EVM56002
Board. There are applications for VHF 1200/9600 packet, 1200 BPSK packet,
Rtty/Ascii, Amtor and Pactor (Tx/Rx on FEQ and ARQ), SSTV, Fax, and APT
interfaces to Jvfax 7.1, and several nice audio filters. I really stable
and win95 compatible Flexnet drivers (I have been told that these are being
developed by the Flexnet
group), and Pactor ARQ Tx. You can begin take a look here.
I have setup a
server with almost everything mentioned here. It's manually updated (no
mirror, for TAPR compliance), and is really meant for near users, as the
link is very good with Spain, good with Europe and from bad to very bad
to N/S America. The server is located at ftp://det.bi.ehu.es/pub/ham
If you are the author of some soft and you want to update it, please, put
it in the incoming dir of the same server and send me a message.
Collection of EVM56K Applications
There is a new
page only for EVM also at TAPR, it is at Motorola
DSP-4 is a board
based on a Motorola 56001 DSP, much of the software available for the EVM
derives from it and there is a good documentation about the implementation
of 1200/9600 modems and filters. Take a look at vk4yeq
You can also check
some articles (in Spanish) by Jabi
Agirre EA2ARU and me.
There is for example,
another source of soft and text for TI TMS320C25 and Morotola DSP56002
EVM is Jürgen Hasch DG1SCR's page DSPs
for Radio Amateurs . Buried in this page, there is a flexnet driver
for the EVM here
. At present, it is experimental.
The first one is based on a Johan KC7WW article published in QEX. It's
The second one is the continuation of the first one. It explains how to
link interfaces to the EVM, and a EPROM with several modems. It's here
The third and last at present. Gives the absolute beginner a guide to put
the board at work and how to modify the sources in order to adapt them
to his interface. It's here.
contributions have arrived. They include a DOS/Linux loader through
the SCI port (no more serial port switching). They are available primarily
at TAPR Dsp Recent Upload Area as n1owu_11.zip
There is some
activity based on Linux this time by D.Jeff Dionne, he has some utilities
as a loader, asembler and compiler available at ftp://ftp.pfnet.com/pub/m56k
where there is activity is the use of high level languages for programming
the EVM. Johan's work is available as cevm*.* in TAPR
Dsp Recent Upload Area. He includes also information for preparing
a memory expansion for the board, as C programming is very RAM hungry.
Doug's is also going to put information about his work in this area.
(the author of EVM56K...) has a server here
There are development
tools and a nice free scope application here
, at Tasking.
been told that Jabi Agirre is
promoting a low cost radio-interface to this board and also offers the
board at an agressive prizing.
are now several exciting new modes for HF that envolve working with
weak signals. You can read an article by Johan KC7WW that compares both
of them in his article Recent
HF Communications Advancements :
One of them is PSK31, based on Pawel Jalocha's slowbpsk that has been reworked
by Peter Martínez G3PLX. You can find technical details here.
It's a mode for HF keyboard to keyboard communication that is regularly
used by several people both in Europe and USA.In it's present incarnation
it includes Viterbi coding and QPSK modulation. You will find the following
versions and more information in the PSK31
WWW Homepage :
PSK31 for Texas DSK
C50 with QPSK DOS Version by Andrew Senior G0TJZ
PSK31 for Motorola EVM 56002 on DOS with QPSK equivalent to the
Windows SB and EVM versions. By Peter Martinez G3PLX
PSK31 for Analog Devices SHARC
Evaluation Board, Windows Version by Michael Keller DL6IAK
PSK31 for Linux
and SoundBlaster by Hansi Reiser DL9RDZ. Although it's not full-duplex,
it comes with full sources.
PSK31 for EasyDSP
unit on DOS by Ulrich DF6JB. It's available here
New version for Windows and SHARC EZ-Lite that adds to the "standard" modes
variable transmission-speeds (PSK16-124 ) with stronger QPSK modes up to
constraint length 9 by Michael DL6IAK: mpskwin.zip
Motorola EVM 56002 on Windows Version 1.24 With help, tunnig aids, and a waterfall indicator for
easier tunning and a receive overload indicator. New version with
Soft-decision Viterbi, better squelch, better AFC. by Peter G3PLX.
version (1.05) for Windows and NT and Soundblaster. By Peter G3PLX. Now with more
help, bigger waterfall display for easier tunning and overload indicator,
it sets the sample-rate better and can handle really way-off-frequency
You can hear these modes here: Note that these files will be correctly
decoded if feeded on the DSP, that's why they are so lengthy. Note the
preamble at the start and end of the transmission. If you only want to
know how they sound, you can get the ADPCM compressed version (I haven't
tested if they decode correctly)
mode calling CQ. Compressed here.
mode calling CQ. Compressed here.
You can see also how much spectrum they use. These images have been obtained
has published a very informative article (in english) in RADCOM magazine.
Editors have agreed and we are able to read it here in PDF*
format. It's here
The other one is Coherent BSPK by Bill de Carle VE2IQ. This software is
intended to be used with two fine boards (Sigma A/D) he produces. You can
read an article by Lyle K0LR about Coherent BPSK here.
Johan KC7WW has prepared an interface that let's you use Coherent with
the EVM. Perhaps you will need to add some lines and level shifters to
your interface. The interface is available here
and the program is available at Bill's BBS.
These are the schedules: 14.081 at 1600z weekdays, 18.081 at 1700z especially
on week-ends and 1.881 at 0300z (Mainly USA roundtable). There is a new
program from Bill called Africa
and available at his BBS.
You can hear how this mode sound. Take in count that Coherent is very configurable
in terms of speed and coding, Here is Coherent
on MS25 and ET 1 calling CQ. Compressed here.
You can see also how much spectra does Coherent use here.
is also a 64 Tone Paralell modem by Pawel Jalocha, that works very well
under heavy QRM and QSB.. It's available here.
also a 15 Tone Paralell modem by Pawel Jalocha, with an KISS/AX.25 interface
that seems promising. Any test?. It's available here.
Here is how MT63
sounds calling CQ. Compressed here.
This mode uses much spectrum, you can take a look at it here.
There is a
Web page that shows how to use MT63 here
There is a
Beta Version of MT63 that offers several differences as CWID and variable
bandwidth (500Hz, 1000Hz and 2000Hz). It's here.
It includes an split window DOS Terminal.
two new aplications by Peter Martinez, one is an audio spectrum analyzer
EvmSpec that you can get here.
And the other is general purpose loader that can be used to load applications
from the command line and to let G3PLX applications automatically load
the EVM. You need an ATMEL 29C256 eeprom. It's named PlxBoot and it's here.
Here is how QPSK
sounds sending a AX.25 SABM packet. Compressed here.
This is a spectrum
KC7WW has released a beta modem and associated program that implements
PACTOR and AMTOR. I have tried it and it works. Soon there will be sources
available. You will need the same modifications to the interface board
as for the coherent interface. It's available here.
SV/N1OWU has prepared a Win95 package that implements Hell (an abbreviation
of 'Feldhellschreiben'). It's rather amusing. There are nets in Europe
on Sunday at 1200Z on 7035 and at 1400Z 10137. The package is available
You can hear how it sounds here, note the idle dit-dit at the end of transmission: Hell
calling CQ. Compressed here.
ZL1BPU has prepared a nice page about Feldhell and similar modes it's the
page of the Fuzzy Digital Modes. There are available there several
programs including Mosaic2 by himself.
about new MTHell Record between ZL1BPU
we are able to use two packages by Peter G3PLX that implement a Windows
terminal and a Windows MTHell
(Multitone Hell) terminal. Both are for the Motorola EVM.
has prepared a AMPOP emulator (the hardware used with hamcomm and Jvfax).
It's an alpha and read the doc as you perhaps will need to make some more
connections to your interface to reroute signals as AMPOP compatible programs
use. It's available here.
Here is how MTHell
sounds calling CQ. Compressed here.
This is how you can read
it with a spectrogram program like GRAM.
SV/N1OWU has prepared a new downloader for Windows95/NT it's dl32.zip.along
with an EEPROM you can download files to the EVM using the serial conector
on the EVM you also need a eeprom.
are several articles
in German from Fred OH/DK4ZC about PSK31 and Feldhell
is just promoting a case and interface for the EVM56002 take a look at
it will be directly compatible with Dough's and Johan's software.
EA2ARU has just adapted several modems that Ulrich Bangert DF6JB coded
for his EasyDSP
Unit They should be used with the fine JvComm32 program by
Eberhard Backeshoff that is available
. The modems itself are available here: AmFax95,
Perhaps they could be adapted for other programs.
prepared two articles in Spanish about New Digital Modes on HF. One of
them is a 2 pages article written and acepted for the Ursi98
Spanish Conference that you can download or view online in PDF*
format here. The other one is longer and
appeared in the December 1998 Radioaficionados
Magazine and you can get it also in PDF* format
has re-released a bios2.asm
file that is compliant with TAPR EVM interface and that also has get rid
of several small bugs.
has released a modem for getting Differential
GPS information from the Coast Guard broadcasts. I cannot test it in
Spain as at this moment that service is not available here.
another DSP in use on Ham applications the Texas
Instruments TMS320 family (the C26 and C50 families). As far as I know
there are applications for VHF 1200/9600 packet, Rtty/Ascii, Amtor and
Pactor (Tx/Rx on FEQ and ARQ !!!), Flexnet drivers, and several nice audio
filters. I miss here the Jvfax 7.1 Interface You can begin take a look
Sailer, HB9JNX there are Rtty/Ascii, Amtor and Pactor terminal for
are also drivers for these (C26
boards for Flexnet in the Flexnet
page that along with the TFemu
package give a TheFirmware emulation.
is a new version of Andrew's PSK31 terminal for the C50 that does offers
QPSK and Viterbi coding it's here.
Alberto di Bene I2PHD and Vittorio De Tomasi IK2CZL have prepared
a nice program Dspbox for the C50 kit that converts it in a notch, denoiser,
passband and automatic AGC DSP box. It's really awesome, take a try. A
new version that works flawlessly on fast computers has been released.
another DSP, the Analog
Devices 21000 SHARC Family, that is begining to have use in HAM by
the hand of Michael Keller DL6IAK.
He has just developed a PSK31
version for this platform, and he has also been working on a RTTY modem
Sites that are worth
to take a look
want to hear several HF modulations?. Here
you can several modulations.
Some usage info...