coding by N2MOH

Frank Gentges
Thu, 18 Mar 1999 03:18:20 +0000 (GMT)

As you probably know AMRAD is taking a look at LF and has recently been 
licensed to operate there.  We would like to build the technology to work 
the British amateurs that are now on 136 kHZ.  Our biggest problem is the 
signal to noise ratio on their signals is extrapolated to be much lower 
than conventional narrowband receivers can detect.

We have been using some PC FFT programs with 2Hz cells and signal 
integration without seeing their signals.  If your would like to look at 
programming a much narrower FFT or other schemes we would be very 
interested in trying out your work.

A number of programs have been written but source code is scarce and many 
do not work with the peculiarities of the soundblaster "compatable" sound 
cards built into notebook computers.  We have found that desktop PCs 
generate a lot of LF noise probably from the monitor horizontal 
circuits.  Notebooks with LCD displays, on the other hand, work alongside 
our sensitive receivers much better.  Our group has also been discussing 
other modulation schema for transmitting data at very slow rates but 
right now we cannot even detect a carrier so are looking to walk first 
with an eye towards running.

I can refer you to much other material if your are interested.

Frank K0BRA

On Fri, 12 Mar 1999, Greg Glass wrote:

> I don't know it this is the right address, but I see that you are
> looking for programmers.
> I have been a programmer since 1965.  For the last (almost) 20 years I
> have been working on computer graphics projects.  Lately that has been
> internet related stuff.  I work mostly in Java, C++ and C on windows.
> I don't know if there is anything that I could help you with but I have
> some available bandwidth.
> By the way I have been a very inactive HAM