Re: VLF: EbNaut transmissions on lower frequencies?, pre-tests: 6.47kHz

[Paul Nicholson <vlf0403@abelian.org>]

>  i saw that the decoder seems to have a problem with
> the character '&', see attachment. Is it a Windows problem?

Very odd.  Doesn't want to display the ampersand.

I expect it shows the ampersand in the log file.

Looks like windows does something unexpected with the
ampersand in the SetWindowText() function.  The principal
of maximum surprise at work here (maybe should be maximum
dismay).  ... ... Not well documented, but I found something
horrible, deeply buried on a Microsoft site.  Remind me
never to write software for Windows, it always smells bad.

>  i would like to try 40 characters

Sure.  5 to 7 days depending on conditions, and about
double again for the 75 chars.

> How accurate are your phase measurements arround an
> Eb/N0 of -4 dB?

Not bad I think.  The phase is measured over the whole
transmission after the modulation is reversed.  So there
is 15dB in 40uHz to make use of, on each 20 character day.
The S/N per symbol or per info bit, may be terrible but
on a long message the overall S/N is quite good.

--
Paul Nicholson
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