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:
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