Return-Path: Received: from mtain-mg07.r1000.mx.aol.com (mtain-mg07.r1000.mx.aol.com [172.29.96.207]) by air-dc09.mail.aol.com (v127_r1.1) with ESMTP id MAILINDC091-86054b8a6abd6e; Sun, 28 Feb 2010 08:08:13 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mg07.r1000.mx.aol.com (Internet Inbound) with ESMTP id 930B0380000AD; Sun, 28 Feb 2010 08:08:11 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NlirW-0004RP-3S for rs_out_1@blacksheep.org; Sun, 28 Feb 2010 13:07:10 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NlirV-0004RG-In for rsgb_lf_group@blacksheep.org; Sun, 28 Feb 2010 13:07:09 +0000 Received: from imr-da06.mx.aol.com ([205.188.169.203]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NlirS-0007ZA-Oa for rsgb_lf_group@blacksheep.org; Sun, 28 Feb 2010 13:07:09 +0000 Received: from mtaout-db06.r1000.mx.aol.com (mtaout-db06.r1000.mx.aol.com [172.29.51.198]) by imr-da06.mx.aol.com (8.14.1/8.14.1) with ESMTP id o1SD6p1d013347 for ; Sun, 28 Feb 2010 08:06:51 -0500 Received: from Black (e179166161.adsl.alicedsl.de [85.179.166.161]) by mtaout-db06.r1000.mx.aol.com (WebSuites/MUA Thirdparty client Interface) with ESMTPA id 6EA39E00008A for ; Sun, 28 Feb 2010 08:06:50 -0500 (EST) Message-ID: From: "Markus Vester" To: References: In-Reply-To: Date: Sun, 28 Feb 2010 14:06:35 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6000.16480 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16669 x-aol-global-disposition: G x-aol-sid: 3039ac1d33c64b8a6a6a6fc0 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Re: 9kHz noise level Content-Type: multipart/alternative; boundary="----=_NextPart_000_0010_01CAB87F.3D1D05B0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.9 required=5.0 tests=HTML_30_40,HTML_MESSAGE, MISSING_OUTLOOK_NAME autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G x-aol-sid: 3039ac1d60cf4b8a6abb02cc X-AOL-IP: 193.82.116.20 ------=_NextPart_000_0010_01CAB87F.3D1D05B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Dear Alexander, LF, the frequency rulers of the modified Argo are actually correct, and yo= u can see how I reduced the bandwidth when going further away. The min= imum setting was 90 second dots, giving 0.042 Hz FFT resolution when= running at 4x normal samplerate (ie. 0.063 Hz noise BW) . The marginal "T" trace at 6 km was probably no more than 0 dB SNR. Thu= s the noise level (including spherics) would have been on the order of= 15 dBuV/m/sqrtHz. Best 73, Markus, DF6NM ----- Original Message -----=20 From: Alexander S. Yurkov=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Sunday, February 28, 2010 6:33 PM Subject: Re: LF: Re: 9kHz noise level On Sat, 27 Feb 2010, Markus Vester wrote: > In April 2003, I attempted to transmitt an 8.97 kHz carrier, radia= ting=20 > about 1 microwatt from my normal LF antenna (220 pF at ~ 9m eff. > height). I drove around and stopped in different places, putting= up a 6m > fishing pole with a wire, connected to a resonant circuit and the= laptop > soundcard. Each time I took a short Spectrogram full-band screensh= ot, > along with a narrowband capture from a special Argo version, patch= ed for > 22 kHz samplerate. An assembly of the screenshots is at > http://freenet-homepage.de/df6nm/8970_ALL.gif. Maximum detection= range > was 6 km, just marginally outside the reactive nearfield. No > noiseblanking was attempted at the time. Dear Markus, In what qrss mode (FFT-bandwith) you resived such a signal? P=3D1uW= D=3D6km yelds E=3D1.3uV/m It seems to be usefull to estimate noise level. Bu= t we should normalyze this to bandwith. Regards, Alexander/RA9MB ------=_NextPart_000_0010_01CAB87F.3D1D05B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Dear Alexander, LF,
 
the frequency rulers of the= modified Argo=20 are actually correct, and you can see how I reduced the band= width when=20 going further away. The minimum setting was 90 second= dots,=20 giving 0.042 Hz FFT resolution when running at 4x normal sam= plerate=20 (ie. 0.063 Hz noise BW) .
 
The marginal=20 "T" trace at 6 km was probably no more than 0 dB SNR. Thus the no= ise level=20 (including spherics) would have been on the order of 15=20 dBuV/m/sqrtHz.
 
Best 73,
Markus, DF6NM
----- Original Message -----
Sent: Sunday, February 28, 20= 10 6:33=20 PM
Subject: Re: LF: Re: 9kHz noi= se=20 level
=
On Sat, 27 Feb 2010,=20 Markus Vester wrote:
> In April 2003, I attempted to transmitt= an 8.97=20 kHz carrier, radiating
> about 1 microwatt from my normal LF= antenna=20 (220 pF at ~ 9m eff.
> height). I drove around and stopped in= different=20 places, putting up a 6m
> fishing pole with a wire, connected= to a=20 resonant circuit and the laptop
> soundcard. Each time I took= a short=20 Spectrogram full-band screenshot,
> along with a narrowband ca= pture from=20 a special Argo version, patched for
> 22 kHz samplerate. An as= sembly of=20 the screenshots is at
> http://freenet-homepage.de/df6nm/8970_ALL.gif<= /A>.=20 Maximum detection range
> was 6 km, just marginally outside th= e reactive=20 nearfield. No
> noiseblanking was attempted at the time.
Dear=20 Markus,
In what qrss mode (FFT-bandwith) you resived such a signa= l? P=3D1uW=20 D=3D6km
yelds E=3D1.3uV/m It seems to be usefull to estimate nois= e level. But=20 we
should normalyze this to=20 bandwith.

Regards,
Alexander/RA9MB



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