Delivered-To: daveyxm@virginmedia.com Received: by 10.50.237.98 with SMTP id vb2csp820771igc; Mon, 30 Dec 2013 13:09:07 -0800 (PST) X-Received: by 10.180.171.34 with SMTP id ar2mr45698375wic.25.1388437746085; Mon, 30 Dec 2013 13:09:06 -0800 (PST) Return-Path: Received: from post.thorcom.com (post.thorcom.com. [195.171.43.25]) by mx.google.com with ESMTP id e5si5227194wic.41.2013.12.30.13.09.05 for ; Mon, 30 Dec 2013 13:09:06 -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 1Vxjld-0005WX-6l for rs_out_1@blacksheep.org; Mon, 30 Dec 2013 20:48:53 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Vxjlc-0005WO-BC for rsgb_lf_group@blacksheep.org; Mon, 30 Dec 2013 20:48:52 +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 1VxjlY-00082C-3O for rsgb_lf_group@blacksheep.org; Mon, 30 Dec 2013 20:48:51 +0000 Received: from omta16.emeryville.ca.mail.comcast.net ([76.96.30.72]) by qmta08.emeryville.ca.mail.comcast.net with comcast id 7w2y1n0051ZMdJ4A8wol2M; Mon, 30 Dec 2013 20:48:45 +0000 Received: from Owner ([166.137.182.216]) by omta16.emeryville.ca.mail.comcast.net with comcast id 7woQ1n0094gYbxS8cwoW8W; Mon, 30 Dec 2013 20:48:40 +0000 From: "hvanesce" To: References: <079a01cf057b$1af87300$50e95900$@comcast.net> <52C1BBFD.1040902@freenet.de> In-Reply-To: <52C1BBFD.1040902@freenet.de> Date: Mon, 30 Dec 2013 13:48:14 -0700 Message-ID: <07f201cf05a0$7fd95710$7f8c0530$@comcast.net> MIME-Version: 1.0 X-Mailer: Microsoft Outlook 14.0 Thread-Index: AQIKPwBDPF0MmX4t2WStNf3J0D+AKgH9qfvmmebQwiA= Content-Language: en-us DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20121106; t=1388436525; bh=NsCMHWfqXjv3AtgWyFhmCyVnux/yZzbcX9p8ujmXnco=; h=Received:Received:From:To:Subject:Date:Message-ID:MIME-Version: Content-Type; b=oL9qng7Jsm+uU116Vg4USncbhasOiho4dLaX0Pugb33idxZqJAtdvIcrEyhQmH15g q8ls98Hsdwp5Ym18fC/j71Z2sFetbIQnMDcCi1dvZRxY3mK2wmt46ZdtxXfvWkiMXw rJEB3JYkAoRsUFJKPfcTi5wrAqjKKUuXyDDuDgxk4ZInlUdq9MUsM0uJ4AnvB4Pgbx CCFm1TUALr3M4Fs1YqCcfcahd0nKDMK2VawLd3TiDn0A5Pm+zEThaPB8/HEVIF7OLg k4lskw9jQw1kbQj9MgeGek0cGeURfwuI7aRPUqKPNdqJfAP0f2PLAximOw+ZStJCc6 v7r9CyQan3iEg== 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: Wolf, Thank you for the information. I opened the link that you provided and read most of the document; this is a big help. I am in the early stages of familiarizing with the Spectrum Lab manual, and did not realize that Spectrum Lab had such user-friendly synchronization options; they are most impressive. I will experiment with synchronizing to NPM, NAA and NML (those three signals are often within 5dB of one another here). The sample rate and frequency calibration document to which you provided a link will be a big help. [...] 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: ebcef237b0394d499a293e835099e25a Subject: RE: LF: Frequency Check Content-Type: multipart/alternative; boundary="----=_NextPart_000_07F3_01CF0565.D37B4260" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,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: 1505 This is a multipart message in MIME format. ------=_NextPart_000_07F3_01CF0565.D37B4260 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Wolf, Thank you for the information. I opened the link that you provided and read most of the document; this is a big help. I am in the early stages of familiarizing with the Spectrum Lab manual, and did not realize that Spectrum Lab had such user-friendly synchronization options; they are most impressive. I will experiment with synchronizing to NPM, NAA and NML (those three signals are often within 5dB of one another here). The sample rate and frequency calibration document to which you provided a link will be a big help. I am also waiting for delivery of a Thunderbolt GPSDO, and I noticed and reviewed the very thorough description of 1pps GPSDO interfacing and configuration, in your sample rate and frequency calibration document. Sincere thanks to you for all of this great software and the excellent documentation, it is all much appreciated. 73, Jim AA5BW From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of wolf_dl4yhf Sent: Monday, December 30, 2013 11:31 AM To: rsgb_lf_group@blacksheep.org Subject: Re: LF: Frequency Check Hello Jim, Stefan, and all, Jim's screenshot definitely shows the 'Alpha' (RSDN) signal. It's often difficult to tell which of the lines is the theoretic 'center' frequency - depending on how the various stations from Russia arrive at your QTH, the carriers may be in-phase or out of phase (i.e. cancel each other). But you can alternatively check the sampling rate by fractions of a Hz (or even a milli-Hertz) if NAA or NML is sufficiently strong at your QTH. I have checked both here (as far as the signal strength permits) against a GPSDO, and their center frequencies seem to be very accurate (like most of the European navy transmitters, too). How to use these VLF MSK transmitters to 'calibrate' the soundcard's sampling rate (in software) is described here: http://www.qsl.net/dl4yhf/speclab/frqcalib.htm#MSK_signals There should be two peaks in the spectrum shown in the calibrator's scope window. These are located symmetrically around the carrier frequency of the MSK signal, after the signal has been squared. The difference between the two narrow peaks depends on the transmitter's bitrate. All the best, Wolf . 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 ------=_NextPart_000_07F3_01CF0565.D37B4260 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Wolf,

 

Thank you for the = information. I opened the link that you provided and read most of the = document; this is a big help. I am in the early stages of familiarizing = with the Spectrum Lab manual, and did not realize that Spectrum Lab had = such user-friendly synchronization options; they are most impressive. I = will experiment with synchronizing to NPM, NAA and NML (those three = signals are often within 5dB of one another here). The sample rate and frequency calibration document to which = you provided a link will be a big help.

 

I am also waiting for = delivery of a Thunderbolt GPSDO, and I noticed and reviewed the very = thorough description of 1pps GPSDO interfacing and configuration, in = your sample rate and frequency calibration document. Sincere thanks to = you for all of this great software and the excellent documentation, it = is all much appreciated.

 

73,   Jim = AA5BW

 

From: owner-rsgb_lf_group@blacksheep.org = [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of = wolf_dl4yhf
Sent: Monday, December 30, 2013 11:31 = AM
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: = Frequency Check

 

Hello = Jim, Stefan, and all,

Jim's screenshot definitely shows the = 'Alpha' (RSDN) signal. It's often difficult to tell which of the lines = is the theoretic 'center' frequency  - depending on how the various = stations from Russia arrive at your QTH, the carriers may be in-phase or = out of phase (i.e. cancel each other).

But you can alternatively = check the sampling rate by fractions of a Hz (or even a milli-Hertz) if = NAA or NML is sufficiently strong at your QTH. I have checked both here = (as far as the signal strength permits) against a GPSDO, and their = center frequencies seem to be very accurate (like most of the European = navy transmitters, too).
How to use these VLF MSK transmitters to = 'calibrate' the soundcard's sampling rate (in software) is described = here:

http:= //www.qsl.net/dl4yhf/speclab/frqcalib.htm#MSK_signals

There = should be two peaks in the spectrum shown in the calibrator's scope = window. These are located symmetrically around the carrier frequency of = the MSK signal, after the signal has been squared. The difference = between the two narrow peaks depends on the transmitter's = bitrate.

All the best,
  Wolf .

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

 

------=_NextPart_000_07F3_01CF0565.D37B4260--