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Date: Tue, 05 Oct 2010 00:50:26 +0200
From: =?ISO-8859-1?Q?Stefan_Sch=E4fer?= <schaefer@iup.uni-heidelberg.de>
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Subject: Re: VLF: Re: DK7FC's 7th VLF kite experiment
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Hello Piotr,

Nice to see/read again from you here on the reflector! :-)

Thank you for your very nice words and for the effort on updating the=20
propagation model for my current setup! It is very interesting for me!!=20
If the S/N in 904 km is so good and the E field decrease (as a function=20
of distance) is like you show, i assume a transatlantic=20
contact/reception is not to far away! All the things that happend in the=
=20
last time is still a little unbelivable for me, it takes some time ;-)
The link to the IEEE paper is very interesting as well! Maybe the=20
scientists over there are interested to take part on the experiments? Do=
=20
you know some of them? Maybe we can combine the amateurs and the=20
scientific work, although they will have no appreciation if i transmit=20
"73" instead of a constant carrier ;-)

Will you try to receive on the next experiment as well?

Vy 73 and i wish you all the best!

Stefan/DK7FC

PS: If you have the time, could you give us some ideas to compare 8970=20
Hz and 6470 Hz? Or even 5170 Hz if i can set up a 300m vertical? Maybe i=
=20
should do the first test on 5170 Hz before you take the effort ;-)

Stefan/DK7FC



Am 04.10.2010 22:44, schrieb Piotr Mlynarski:
> Stefan Sch=E4fer pisze:
>> Wow!
>> Dear VLF,
>> This was very nice to read. So many messages and so many positive=20
>> receptions. I am really impressed!
>>
>> *Many thanks to you all* who have been active on this day, watching=20
>> on 8,97 kHz,  the Dreamers Band :-)
>>
>> *We have a new world record of the maximum distanced reception on VLF=
=20
>> (by amateurs): SQ5BPF at a distance of 904 km with excellent S/N.*=20
>> Congratulations!! See attached picture.
>>
>> Thanks to Markus/DF6NM for QSP to the reflector. Sorry to Wolf/DL4YHF=
=20
>> that i was not QRV on 2m CW but there were problems to that time (see=
=20
>> below). Thanks to SQ5BPF for the positive SMS ;-) Thanks to the US=20
>> and canadian stations who tried to receive the signal. It becomes=20
>> more and more probably since the S/N values are impressive here in EU.
>>
>> Congratulations to all successful receiving stations, especially the=20
>> new ones (on 8970 Hz) which are as far as i can see: Daniele Tincani,=
=20
>> SQ5BPF, DD7PC, DF0WD, F1AFJ (683 km since my locator is/was JN49IS),=20
>> F5WK (very impressive S/N 25 dB at 460km distance!), DL3ZID(463 km) :-)
>
> Dear Stefan, VLF ,
>
> Congratulations to you for ,again, your remarkable efforts, passion,=20
> knowledge and skills resulting in another, world-wide acknowledged VLF=
=20
> experiment.
> Unfortunately, i  was away from home by the time the experiments were=20
> taking place so i could only read e-mails with rx reports and remarks.
> I guess you recall some discussion about field strength ,propagation=20
> models etc.. among some "Dreamers" which took place, here,
> on this reflector, after your second/third vlf experiment. Paul=20
> Nicholson has introduced us to a paper dealing with some theoretical=20
> considerations
> about EM waves travelling in  earth-ionosphere waveguide:
> http://dspace.mit.edu/bitstream/handle/1721.1/16973/53712465.pdf;jsessio=
nid=3D995C2F2A8DC7FFC28D518D8FF1745D7C?sequence=3D1=20
>
> I 've written fortran code based on egn. 5.2 of the above paper and i=20
> have already presented some theoretical estimates
> based on data taken from your previous experiments. Today, i present=20
> another theoretical  E-field strength estimate( attachment) based upon=
=20
> your recent setup
> i.e with assumed antenna current of 1 Amp and its vertical length  of=20
> 200 meters. The height of ionosphere has been assumed to vary between=20
> 60 and 80 km
> f =3D 8970 Hz.  A separate, 'single point' calculation has also been=20
> made for the tx-rx distance of 904 km
> i.e. between you and Jacek,sq5bpf and the calculated effective field=20
> values for 60,70,80 km of ionosphere height are: 3.32; 2.85; 2.49=20
> respectively
> (expressed in microVolts/m).
>
>                                                                       =
                     =20
> 73, Piotr,  sq7mpj
>
> p.s.
> in the course of collecting some literature dealing with propagation=20
> models of EM waves in the ELF_VLF_LF range; 'receivers' and 'antennae'
> i have found an interesting paper which title ( and contents) reads (=20
> in our,radioamateur vocabulary)
> as simply another loop antenna and receiver for VLF reception  :-)
> http://www-star.stanford.edu/~vlf/publications/2010-02.pdf
>
>
>
>
>
>