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[195.171.43.25]) by mx.google.com with ESMTP id 7si29559347eeo.229.1969.12.31.16.00.00; Tue, 08 Oct 2013 15:13:57 -0700 (PDT) Received-SPF: neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) smtp.mail=owner-rsgb_lf_group@blacksheep.org; dkim=pass header.i=@mx.aol.com Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1VTfWH-0005ij-WB for rs_out_1@blacksheep.org; Tue, 08 Oct 2013 23:12:45 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1VTfWH-0005ia-8d for rsgb_lf_group@blacksheep.org; Tue, 08 Oct 2013 23:12:45 +0100 Received: from omr-m09.mx.aol.com ([64.12.143.82]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1VTfWE-0004Ea-KI for rsgb_lf_group@blacksheep.org; Tue, 08 Oct 2013 23:12:44 +0100 Received: from mtaout-db02.r1000.mx.aol.com (mtaout-db02.r1000.mx.aol.com [172.29.51.194]) by omr-m09.mx.aol.com (Outbound Mail Relay) with ESMTP id 5883F700000A8; Tue, 8 Oct 2013 18:12:40 -0400 (EDT) Received: from White (95-91-237-85-dynip.superkabel.de [95.91.237.85]) by mtaout-db02.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id 67568E00009F; Tue, 8 Oct 2013 18:12:39 -0400 (EDT) Message-ID: <7DA570935EC8481A950D4B6845E2DA74@White> From: "Markus Vester" To: <600m@yahoogroups.com>, References: <5253513B.7030805@virginbroadband.com.au> Date: Wed, 9 Oct 2013 00:12:38 +0200 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 12.0.1606 X-MimeOLE: Produced By Microsoft MimeOLE V12.0.1606 x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1381270360; bh=jLSlfV9He+HynGhJi3TTIKiRDQibzSqCTYZPAU7fMDk=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=V1Dizhn1ucznNBTu6AzEPpk/6q92hrnPfZoPe9ttVF1jSZGOb1eF/U+NOmhssHlty qAV3o+/ID18ci6yekv60t8MnHA4/sa3zkeyzS8dBwpnhRqRSBQSRVvpguSSmQyIsyX Pj0XtiH5EA73JKIpypw3v7t5tbcjY555F8RqUQfY= x-aol-sid: 3039ac1d33c2525483576009 X-AOL-IP: 95.91.237.85 X-Spam-Score: -0.3 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Edgar, this sounds like a very interesting concept, though perhaps not easy to realize. In principle, the two reference frequencies would allow you to measure and track both the samplerate ratio and the LO difference between the receivers. By interpolating and frequency shifting of one of the data streams, you will generate phase-coherent channels, allowing you to create a two-element steerable array. Maximum ratio combining for HGA could then be used maximize the gain towards Europe while minimizing noise pickup from other directions. [...] Content analysis details: (-0.3 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [64.12.143.82 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (markusvester[at]aol.com) -0.0 SPF_PASS SPF: sender matches SPF record -0.3 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 92b6515a4252c45136e975e6745a1e0d Subject: Re: LF: Signal detection question Content-Type: multipart/alternative; boundary="----=_NextPart_000_0042_01CEC484.431A0930" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_20_30,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 Status: O X-Status: X-Keywords: X-UID: 2962 Dies ist eine mehrteilige Nachricht im MIME-Format. ------=_NextPart_000_0042_01CEC484.431A0930 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Edgar, this sounds like a very interesting concept, though perhaps not easy to = realize. In principle, the two reference frequencies would allow you to measure = and track both the samplerate ratio and the LO difference between the = receivers. By interpolating and frequency shifting of one of the data = streams, you will generate phase-coherent channels, allowing you to = create a two-element steerable array. Maximum ratio combining for HGA = could then be used maximize the gain towards Europe while minimizing = noise pickup from other directions. However there may be some limitations in that approach. Due to the large = receiver baseline (26 lambda), you cannot avoid creating a feathered-up = antenna diagram with many narrow lobes. The largest benefit could arise = from the ability to place a null on interference, which won't work so = well with a narrow null versus a distributed noise source like a = thunderstorm field. Also, due to the distances within Europe, maximizing = the gain for HGA will not always necessarily peak the signal from DK7FC. = And with changing propagation, there may also be some variation in = direction of arrival, which would have to be followed by some slow = adaptation of the weighting factor. By these aspects, a simple E-H = cardioid in one of the sites, or a pair of more closely spaced elements = might be an easier choice. I have been following your experiments with interest. Looking at the two = grabbers, Stefan was sometimes visible in Moonah but not (or at least = not much) in Orford. Not sure whether that's due to some intrinsic noise = in the Orford setup (then you might end up making things worse by adding = in Orford data), or Stefan being weakened by the extra distance (then = Orford data would still be useful to partially null QRN).=20 As far as I know, Paul Nicholson is using a somewhat reminiscent setup = on VLF: He has two loops and one E-field probe, whose data streams are = synchronized a posteriori using GPS-derived second ticks. He then = combines the loop signals using adaptive weighting for minimum QRN = level. Best 73, Markus (DF6NM) From: edgar=20 Sent: Tuesday, October 08, 2013 2:26 AM To: 600m@yahoogroups.com ; rsgb_lf_group@blacksheep.org=20 Subject: LF: Signal detection question Hi Group, I have recorded signals from HGA22, DCF39 and DK7FC from two = antenna/receivers at different locations. The locations are 58 km apart. Recordings are 16 bits, mono, 22050 Hz, = and 1.5 hours long. The "space" signal from HGA22, (135430 Hz) is usually stronger than from = DCF39 (138830 Hz). Is the a method that can use the signals of HGA22 (or DCF39) as a clock = (reference) to look for the weak DK7FC signal in the recording? I am wondering if the two wave files could be synchronised in some way = to and then added together to cancel out the noise and highlight the = DK7FC signal frequency. Regards, Edgar Moonah, Tasmania. ------=_NextPart_000_0042_01CEC484.431A0930 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Edgar,
 
this sounds like a very interesting=20 concept, though perhaps not easy to realize.
 
In principle, the two reference = frequencies would=20 allow you to measure and track both the samplerate ratio = and the=20 LO difference between the receivers. By interpolating and frequency = shifting of one of the data streams, you = will generate phase-coherent=20 channels, allowing you to create a two-element steerable array. Maximum = ratio=20 combining for HGA could then be used maximize the gain towards = Europe=20 while minimizing noise pickup from other directions.
 
However there may be = some limitations in that=20 approach. Due to the large receiver = baseline (26=20 lambda), you cannot avoid creating a feathered-up antenna = diagram=20 with many narrow lobes. The largest benefit could arise from the = ability to=20 place a null on interference, which won't work so = well with a=20 narrow null versus a distributed noise source like a thunderstorm = field.=20 Also, due to the distances within Europe, maximizing the gain for HGA = will not=20 always necessarily peak the signal from DK7FC. And with = changing=20 propagation, there may also be some variation in direction of=20 arrival, which would have to be followed by some slow = adaptation of=20 the weighting factor. By these aspects, a simple E-H cardioid in = one of the=20 sites, or a pair of more closely spaced elements might be an easier=20 choice.
 
I have been following your experiments = with=20 interest. Looking at the two grabbers, Stefan was sometimes visible = in=20 Moonah but not (or at least not much) in Orford. Not sure whether that's = due to=20 some intrinsic noise in the Orford setup (then you might end up = making=20 things worse by adding in Orford data), or Stefan being weakened by the = extra=20 distance (then Orford data would still be useful to partially null=20 QRN). 
 
As far as I know, Paul Nicholson is = using a=20 somewhat reminiscent setup on VLF: He has two loops and one E-field = probe, whose=20 data streams are synchronized a posteriori using GPS-derived second = ticks.=20 He then combines the loop signals using adaptive weighting for = minimum=20 QRN level.
 
Best 73,
Markus (DF6NM)
 
 

From:=20 edgar
Sent: Tuesday, October 08, = 2013 2:26=20 AM
To: 600m@yahoogroups.com ; = rsgb_lf_group@blacksheep.org
Subject: LF: Signal = detection=20 question

Hi Group,

I have recorded = signals from=20 HGA22, DCF39 and DK7FC from two antenna/receivers at different=20 locations.

The locations are 58 km apart. Recordings are 16 bits, = mono,=20 22050 Hz, and 1.5 hours long.

The "space" signal from HGA22, = (135430 Hz)=20 is usually stronger than from DCF39 (138830 Hz).

Is the a method = that can=20 use the signals of HGA22 (or DCF39) as a clock (reference) to look for = the weak=20 DK7FC signal in the recording?

I am wondering if the two wave = files could=20 be synchronised in some way to and then added together to cancel out the = noise=20 and highlight the DK7FC signal frequency.

Regards, = Edgar
Moonah,=20 Tasmania.


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