Re: VLF: 8969.99

[Stefan Schäfer <Stefan.Schaefer@iup.uni-heidelberg.de>]

Hello Jim,

Am 27.12.2013 00:10, schrieb hvanesce:

Would 500W into a 300m antenna imply approximately 10mW < ERP < 50mW after coil losses, at 9kHz?

I assume that question is directed to me?
In these experiments i got up to 58mW ERP. A rough calculation of course. It depends on the angle of the kite, which can vary from 80 deg to 40 deg. The average on a windy day is something arround 65 deg.
But for a 300m vertical you will need a special permission in Germany and the air traffic control must be informed 48 hours in advance (giving out a NOTAM). So that was quite an effort. But most exciting! :-) My special permission expired some years ago.
Now the signal is 20 dB weaker, or must be 100x slower. But here i have mains power and don't need wind any more..

73, Stefan/DK7FC

 

Does your antenna orientation and elevation angle vary? (my maximum integration time is dependent on phase rate of change which is dependent on the antenna angle, even if the antenna angle is constant)

 

I enjoyed seeing the strong signals earlier this week on DK7FC, PA1SDB and other grabbers, thanks!

 

73,  Jim AA5BW

 

 

 

From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of uwe-jannsen@kabelmail.de
Sent: Thursday, December 26, 2013 2:53 PM
To: rsgb_lf_group@blacksheep.org
Subject: Re: Re: VLF: 8969.99

 

Hi Stefan and Eddy,

thanks for the reports. the equipment here is the same as ever (500W output into 300m aerial wire).
Markus asked for some OPERA OP4H tests. We have to schedule that test.

GL

Uwe/dj8wx as Tom dj8CAT.

 

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Von: rsgb_lf_group@blacksheep.org
Gesendet: 26.12.2013 13:55
An: rsgb_lf_group@blacksheep.org
Betreff: Re: VLF: 8969.99

---

Hi Uwe, Tom, VLF,

Best signal ever from Tom, capture attached. Is it due to the propagation or did it improve your signal?
What about some tests in OPDS32 or maybe JT9-30? Unfortunately there is permanent rain here so i have to wait some days longer.

73, Stefan/DK7FC

Am 26.12.2013 10:58, schrieb g3zjo:

Hi All

Yes, yesterday was quieter on 8.9KHz with less catastrophic noise pulses. This meant that although Uwe's signal was less strong than during other tests I was in the catchment area. The low signal level means there are breaks in the line here in both 424uH and 47uHz FFT but I was able to catch some nice periods when the signal in 47uHz was10dB above the noise peaks. I can categorically confirm reception.

Thanks Uwe and (Tom DL8CAT) for the signal.

73 Eddie G3ZJO
http://www.g3zjo.talktalk.net/vlfgrabber.htm