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Date: Fri, 29 Oct 2010 19:09:34 +0200
From: =?ISO-8859-1?Q?Stefan_Sch=E4fer?= <schaefer@iup.uni-heidelberg.de>
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Subject: Re: LF: vlf experiments-numerical considerations
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Hi Jacek,

Could you create a picture like plot_80km for distances up to 5000km? I 
think i do not want to start simulating, my job is in the field ;-) But 
you have done it and may generate it easily?

This all is very interesting but i wonder if there are not significant 
propagation differences between the way the waves have to travel (flat 
land, sea, alpes, poles...!)
E.g. Renato Romero has an excellent RX down to DC but my S/N at his 
location was rather poor (compared to other RX stations). So, is it the 
local QRN that may be a little more in the south or maybe due to the 
alps? The S/N between 8970 and 6470 was about the same, as at other 
locations too.
What do the experts think could be the difference between these differnt 
traveling ways?

73, Stefan




Am 29.10.2010 14:58, schrieb Jacek Lipkowski:
> this is a nice plot showing field strength vs frequency and distance, 
> calculated from Piotr's code. please notice that for a given distance 
> there are two frequencies which yield the highest field strength for a 
> constant antenna current - see the second plot, calculated for 904km 
> distance (my distance from DK7FC :)
>
> btw, Piotr's code is very fast!
>
> i made a slightly modified version to include calculating of multiple 
> values, and some additional stuff (compiling via gfortran, a makefile, 
> ploting the data via gnuplot etc). it was used to make these graphs. i 
> can post it if anyone is interested
>
> VY 73
>
> Jacek / SQ5BPF