AMRAD DSP Projects

Here is a dos-based program that can be used to do spectrum analysis with a sound card. spec.zip

Information will appear here soon. As of now, two sources are being made ready to provide the necessary data:

Files from the old phoneline BBS.
Requests made at tacos and the monthly meetings for current updates

There is a third source, and that is YOU, dear web surfer, who may have the most exciting news yet! If so, send email to the webmaster (click on link at the bottom of the page) pronto. As an example of that process, consider the email received from SM5BSZ:

Hello

My name is Leif, SM5BSZ and I am one of those still designing and building all 
the radio equipment for my hobby. I just found out that Amrad exists, and I find 
perhaps here is a group of people sharing my technical interest.

My activity is in design of highly optimised gear for VHF, and I think I have 
shown what can be done by results in the EME contests. I am using a very small 
system, only 4x14 elements on 144MHz, and in recent years I have achieved places 
1 to 4 in the world wide contests with an antenna size (in element count) among 
the small stations.

The way to reach good contest results is partly to use a DSP to produce a 
receive system that is adaptive to the incoming wave both in filtering and 
linear combining the signal pair from a cross yagi system.

The reason I write to you now is the link "DSP/software radios" (I was denied 
access). Maybe others are working on similar things, and would have an interest 
in the algorithms I have been using. My software is written for the particular 
hardware I have, with a TMS320c25, so the actual source code is not of much 
value but the general strategy might be ?

I have placed all information on the internet at:

http://ham.te.hik.se/homepage/sm5bsz/index.htm

Today, the standard desktop computer has an audio board, and processing power 
enough to do all the job, so it should be fairly easy to lift the weak signal 
receive capability for great many amateurs just by making some software 
available.

I think I have most of what is needed, and I will make it available in both 
source code and as executable files on the internet free for anyone and for any 
purpose. But only if I can get from somewhere the drive routines that are 
necessary to use the standard audio boards that people generally use with their 
PC computers.

What I need is some software that will control the sound blaster (clone) and 
that will issue an interrupt every time N new samples are made available in a 
buffer. The software should also read the wave I store in a circular buffer and 
send it to the loudspeaker.

I do not know the policy of amrad and its members, my own is that everything I 
do is free to use for everybody who wants. I know the kind of drivers I need are 
around, and they are used in amateur written software.

So, besides telling about my home page, this E-mail is a question: Is there 
within Amrad, or among its members some software that would solve the "sound 
blaster drive routine" problem - and my interest is only in softwares that can 
be made public and free to use by anyone who likes to do so.

                                       73's

                                        Leif  SM5BSZ

The AMRAD Webmaster

Last modified: Sat Sep 22 22:58:51 EDT 2007