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[195.171.43.25]) by mx.google.com with ESMTP id eo15si17548003wid.26.2013.12.30.10.56.08 for ; Mon, 30 Dec 2013 10:56:08 -0800 (PST) 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 (test mode) header.i=@comcast.net Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1VxhGJ-0004im-H7 for rs_out_1@blacksheep.org; Mon, 30 Dec 2013 18:08:23 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1VxhGI-0004id-Rt for rsgb_lf_group@blacksheep.org; Mon, 30 Dec 2013 18:08:22 +0000 Received: from qmta08.emeryville.ca.mail.comcast.net ([76.96.30.80]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1VxhGF-0007Pb-IT for rsgb_lf_group@blacksheep.org; Mon, 30 Dec 2013 18:08:21 +0000 Received: from omta20.emeryville.ca.mail.comcast.net ([76.96.30.87]) by qmta08.emeryville.ca.mail.comcast.net with comcast id 7sVG1n0031smiN4A8u8HoJ; Mon, 30 Dec 2013 18:08:17 +0000 Received: from Owner ([166.137.182.216]) by omta20.emeryville.ca.mail.comcast.net with comcast id 7u7w1n0014gYbxS8gu817j; Mon, 30 Dec 2013 18:08:12 +0000 From: "hvanesce" To: References: <079a01cf057b$1af87300$50e95900$@comcast.net> <52C1A026.4080909@iup.uni-heidelberg.de> In-Reply-To: <52C1A026.4080909@iup.uni-heidelberg.de> Date: Mon, 30 Dec 2013 11:07:46 -0700 Message-ID: <07c701cf058a$14ee21d0$3eca6570$@comcast.net> MIME-Version: 1.0 X-Mailer: Microsoft Outlook 14.0 Thread-Index: AQIKPwBDPF0MmX4t2WStNf3J0D+AKgHXKeY4mefVXMA= Content-Language: en-us DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20121106; t=1388426897; bh=+5hWIUtw0YBi0U1H8QfgfB50w0LWxVIh71MC48rQ3hw=; h=Received:Received:From:To:Subject:Date:Message-ID:MIME-Version: Content-Type; b=tO7bJvsTb/9KKQclWGAW6AfPXPXUvJnSM8AXOcEROuYGFDBnZoo4SxNeE+KOVhatV xXp7Ky3pRtcqzZNH7icX/WGQdNSgTgotqAsPB8PXbDNu/8ogM4JRwcqVw0/zk2ZDBr 4B7cYy155l37ITGEePuSKLL7qyqfPKpmvYgzbQhDvjqCMz8rhy9xDkfi65Uiss++/d TyxJ3Hrgw8fEfKfEbXlgTCa4e1U+O4MeJ2JP3EHtSpj/9oFfC53Vd8VUdlIOOwp1Pr kKf8VBnBGMAIY6J5NdK1SmuFzkH7/7Ns5AVIBWEZ0XJ14G/tQPZRN8NXCpr96oZov/ i+E5S9cfFG2fw== X-Spam-Score: -0.1 (/) 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: Stefan, Thank you for the help, I’ve made your suggested adjustments to the FFT setting settings. Today I plan to add a second axis to the VLF RX antenna; hoping that steering the antenna (RDF mode?) in SpecLab will provide significantly improved SNR for distant signals (signals for which the required integration time is too long to allow manual steering of the antenna for best SNR). [...] Content analysis details: (-0.1 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [76.96.30.80 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (hvanesce[at]comcast.net) -0.0 SPF_PASS SPF: sender matches SPF record -0.1 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: 40d35b6fcf8b66e4fec28fa30f99f125 Subject: RE: LF: Frequency Check Content-Type: multipart/alternative; boundary="----=_NextPart_000_07C8_01CF054F.68900D20" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_40_50,HTML_MESSAGE 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: 1504 This is a multipart message in MIME format. ------=_NextPart_000_07C8_01CF054F.68900D20 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Stefan, =20 Thank you for the help, I=92ve made your suggested adjustments to the = FFT setting settings. =20 Today I plan to add a second axis to the VLF RX antenna; hoping that steering the antenna (RDF mode?) in SpecLab will provide significantly improved SNR for distant signals (signals for which the required = integration time is too long to allow manual steering of the antenna for best SNR).=20 =20 73, Jim AA5BW =20 From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Stefan = Sch=E4fer Sent: Monday, December 30, 2013 9:33 AM To: rsgb_lf_group@blacksheep.org Subject: Re: LF: Frequency Check =20 Hello Jim,=20 Yes, this is the signal. They do not send a continuous tone but "beeps", thus the sidebands. You need to chance the FFT settings. First, "complex with internal frequency shift", centered to 11904.76 Hz. Next chance the decimate factor, increase it from 1 to 2 and then 4 and then 8 and so on = and see what happens. The FFT input size can be 8192 or so. Enable "1 pixel = per FFT bin" in the first register card of the audio settings and automatic scroll rate. Move the displayed frequency so you can see the lines. You = will see the S/N becomes better when going slower, as expected.=20 Others may give you additional advice... 73, Stefan/DK7FC Am 30.12.2013 17:20, schrieb hvanesce:=20 Stefan, =20 My stable/accurate time reference (GPSDO) should arrive in two weeks; in = the meantime I am hoping to use 11904.76190 Hz (per your suggestion, thanks) = to assess my soundcard clock frequency offset. I have been guessing (based = on comparison with another uncalibrated but stable oscillator) that the frequency offset of my soundcard gives less than 1Hz error at = 11904.76190 kHz.=20 =20 I have attached a screenshot captured over the last 24 hours, showing a modulated signal centered at an indicated frequency (red marker) of 11905.1884 which would have a 0.426 Hz offset from 11904.76190 Hz.=20 =20 The signal seems to be fading about 40dB on a 24-hour cycle, with a = minimum at ~ 2000 UT (clock times in my screen capture are Arizona time, UT =96 = 7 hours). =20 Could the modulated signal shown here be the 11904.76190 Hz signal? =20 73, Jim AA5BW ------=_NextPart_000_07C8_01CF054F.68900D20 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Stefan,

 

Thank you for the help, = I’ve made your suggested adjustments to the FFT setting = settings.

 

Today I plan to add a = second axis to the VLF RX antenna; hoping that steering the antenna (RDF = mode?) in SpecLab will provide significantly improved SNR for distant = signals (signals for which the required integration time is too long to = allow manual steering of the antenna for best SNR). =

 

73,=A0=A0 Jim = AA5BW

 

From: owner-rsgb_lf_group@blacksheep.org = [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Stefan = Sch=E4fer
Sent: Monday, December 30, 2013 9:33 = AM
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: = Frequency Check

 

Hello Jim, =

Yes, this is the signal. They do not send a continuous tone but = "beeps", thus the sidebands. You need to chance the FFT = settings. First, "complex with internal frequency shift", = centered to 11904.76 Hz. Next chance the decimate factor, increase it = from 1 to 2 and then 4 and then 8 and so on and see what happens. The = FFT input size can be 8192 or so. Enable "1 pixel per FFT bin" = in the first register card of the audio settings and automatic scroll = rate. Move the displayed frequency so you can see the lines. You will = see the S/N becomes better when going slower, as expected.
Others = may give you additional advice...

73, Stefan/DK7FC


Am = 30.12.2013 17:20, schrieb hvanesce:

Stefan,

 

My = stable/accurate time reference (GPSDO) should arrive in two weeks; in = the meantime I am hoping to use 11904.76190 Hz (per your suggestion, thanks) to assess = my soundcard clock frequency offset. I have been guessing (based on = comparison with another uncalibrated but stable oscillator) that the = frequency offset of my soundcard gives less than 1Hz error at = 11904.76190 kHz.

 

I have = attached a screenshot captured over the last 24 hours, showing a = modulated signal centered at an indicated frequency (red marker) of = 11905.1884 which would have a 0.426 Hz offset from 11904.76190 Hz. =

 

The = signal seems to be fading about 40dB on a 24-hour cycle, with a minimum = at ~ 2000 UT (clock times in my screen capture are Arizona time, UT = – 7 hours).

 

Could = the modulated signal shown here be the 11904.76190 Hz = signal?

 

73,  Jim = AA5BW

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