Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

Re: ULF: EbNaut message transmitted from ground loop

To: [email protected]
Subject: Re: ULF: EbNaut message transmitted from ground loop
From: DK7FC <[email protected]>
Date: Wed, 10 Apr 2019 08:59:24 +0200
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.de; s=2017; t=1554879565; bh=e275rGaC7ywaSLzFbURFngpeyck0fI3Gh6O5sySYAH4=; h=Date:From:To:Subject:From; b=HIvRvMp77imqtpEa1U77QyG+X8mq6o/CzOEzx7tZ3B8uo11OQzWz1PjRjGOyVlysw rXOtkRzhC/TK5bA+J81bPFVuDBxdd6WzlUKPQnm5bR86y3T3AJDtnob+H1Y2ciA3hG zsVCobUWhIbNjmx6U9hkYGpM8xyqi5EnOstU4YjL5cvEfNePIPRAobd/qGQ/ik6+xV DjBTxFbNZr6fSsRmMxRPgyjm1E4SBHs7vNlwD2x34j2EWYqkhynYyxZ3mojDskDdOB UaySB39QLA3UqxbHQUYcWPGScXRTmzRBLyjwRJC7hMPLtO9dXJEsPL+jV3leClE8Dc mMklPoR+g+YbA==
In-reply-to: <[email protected]>
References: <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]>
Reply-to: [email protected]
Sender: [email protected]
User-agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3
RR Jacek,

I did not get better results than 15.05 dB using
vtread -T2019-04-06_20:25,+125m /jacek | vtcat -p | vtfilter -a th=4 -h bp,f=2970,w=3000 | vtfilter -h hp,f=2000,poles=8 -h lp,f=3600,poles=14 | vtblank -v -a22 -d0.0005 -t100 | vtmult -f2970.1 | vtresample -r240 | vtresample -r10 > msg.vt Maybe you can get a better result with that command line because your data did not pass the vorbis way.

All this is most fascinating. How is it possible that the signal propagates over to you, into your direction? If you are still in KO02MD, then this is not only a new record distance of 976 km! Also, the bearing is 66 deg between us but the antenna points towards 306 deg, so there is a 60 deg offset between us. Looks like the loop does NOT behave like a loop, at least at night and at that frequency, because there must be a loss of 20 lg(cos60) dB = -3 dB into your direction. Also you have E field only and live in an urban location whereas Paul is 130 km closer and can use E+H fields to optimise the SNR. His SNR is 2 dB better but the loop points almost exactly into his direction. The larger loop has a higher DC (and AC) resistance, so the TX power was not as high as it could have been. I remember how i discussed with Markus on the phone, while TXing, that this may cost 0.5 dB of SNR. This 0.5 dB could have made the success between us! :-)

So, if the loop does not behave like a loop (actually the system loop + propagation path) at night and at that frequency, then we miss the expected gain from a loop at a location that should profit from it. But on the other side we have the chance to detect the signal into a certain range anywhere. How far will that work?


73, Stefan


Am 09.04.2019 22:02, schrieb Jacek Lipkowski:
On Mon, 8 Apr 2019, DK7FC wrote:

Did you use your large computer at work to try to get the best result?

no, unfortunately i had to give it back. but i did a simple search over a small set of parameters (a few hundred -a , -t and -d combinations, and some tests with different filtering).

jacek


<Prev in Thread] Current Thread [Next in Thread>