coding by N2MOH
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.
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