Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mk02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 6C868380000A7; Fri, 2 Sep 2011 08:58:13 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1QzTJ7-00037E-2u for rs_out_1@blacksheep.org; Fri, 02 Sep 2011 13:57:17 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1QzTJ6-000375-GZ for rsgb_lf_group@blacksheep.org; Fri, 02 Sep 2011 13:57:16 +0100 Received: from imr-ma06.mx.aol.com ([64.12.78.142]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1QzTJ3-0000eU-QZ for rsgb_lf_group@blacksheep.org; Fri, 02 Sep 2011 13:57:16 +0100 Received: from mtaout-db04.r1000.mx.aol.com (mtaout-db04.r1000.mx.aol.com [172.29.51.196]) by imr-ma06.mx.aol.com (8.14.1/8.14.1) with ESMTP id p82Cv1vV022076 for ; Fri, 2 Sep 2011 08:57:01 -0400 Received: from White (nrbg-4dbe4151.pool.mediaWays.net [77.190.65.81]) by mtaout-db04.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id 52268E0000AF for ; Fri, 2 Sep 2011 08:56:58 -0400 (EDT) Message-ID: <1798D4FDEAA3470CBFC8D512D3C806C4@White> From: "Markus Vester" To: References: <7D58C8CBA6BE417FB14240FC5573B75C@White> Date: Fri, 2 Sep 2011 14:57:05 +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-SCOLL-SCORE: 0:2:487260416:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: Microhertzing at LF: Content-Type: multipart/alternative; boundary="----=_NextPart_000_0006_01CC6980.94B14E40" 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_40_50,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-SCOLL-SCORE: 0:2:505015808:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d61864e60d2e41a4f X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Dies ist eine mehrteilige Nachricht im MIME-Format. ------=_NextPart_000_0006_01CC6980.94B14E40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Chris, yes, there were good and narrow traces on both grabbers throughout the = dark period, confirming the stability of a long skywave path. In Haifa, = the upward Doppler shift around sunrise was clearly visible. Going by your very useful DCF / HGA plots, there is a day-night = difference of about 30 dB on the DL to 4X path, and 20 dB for YO. I have = left the carrier on to see whether anything would come through in = daylight, but nothing above the noise so far. Thanks very much for offering the chance for this interesting = experiment! Best wishes, Markus (DF6NM) From: Chris 4X1RF=20 Sent: Friday, September 02, 2011 11:38 AM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: Microhertzing at LF: Markus, LF, Your night long transmission appeared nicely in Haifa = http://dl.dropbox.com/u/10280270/4x1rf_DF6NM_QRSS3600_2sept2011.jpg=20 and Bucharest = http://dl.dropbox.com/u/10280270/YO/yo4x1rf_DF6NM_QRSS3600_2sept2011.jpg There's room left for using much less power. Based on last night = results, a 1mW EMRP from you should be about the same level as the = 137780.29445 Loran trace in Haifa. It was a good opportunity to test = both receivers, looking forward to further tests.=20 73s Chris 4X1RF On Fri, Sep 2, 2011 at 1:24 AM, Markus Vester = wrote: trying again... From: Markus Vester=20 Sent: Thursday, September 01, 2011 10:47 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: Microhertzing at LF: Hi Chris, thanks for this! The Saudi Loran traces (GRI 8830) look very accurate = on your 4X grabber. I will try to appear there tonight, and have started = to send a straight carrier on 137780.30. TX power is now reduced to = about 100 mW EMRP. Best 73, Markus From: Chris 4X1RF=20 Sent: Thursday, September 01, 2011 1:34 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: Microhertzing at LF: Markus, LF, As a newcomer to LF I find this as an interesting experiment for real = low power or long distance tests for those who can achieve the necessary = frequency stability requirements. I found this to be quite a = challenge... I have followed your initiative and started similar windows on my = grabbers in YO: http://dl.dropbox.com/u/10280270/YO/TA3600.jpg and 4X: = http://dl.dropbox.com/u/10280270/4X/TA3600.jpg The 4X grabber is currently using the Mercury HPSDR receiver = (http://openhpsdr.org) which is GPSDO locked. However, the audio is = routed to SpectrumLab using Virtual Audio Cable as a virtual sound card. = I have no info regarding VAC sample rate accuracy or how I can = automatically adjust it so this may be a limiting factor, further = experimentation is needed. In the worst case, a real sound card could be = used but then it also has to be locked to GPS. The YO grabber is usually using GQD as a reference for the sound card = sample rate calibration in SpectrumLab and the LF receiver is based on a = laboratory grade VTCXO. GQD being off air, I was forced to use DHO which = is not very reliable during the night for me as can be seen on the = 137.775 Loran line. Thanks for the challenge! 73s Chris 4X1RF ... ------=_NextPart_000_0006_01CC6980.94B14E40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Chris,
 
yes, there were good and narrow traces = on both=20 grabbers throughout the dark period, confirming the stability of a long = skywave=20 path. In Haifa, the upward Doppler shift around sunrise was=20 clearly visible.
 
Going by your very useful DCF / = HGA plots,=20 there is a day-night difference of about 30 dB on the DL to = 4X path,=20 and 20 dB for YO. I have left = the carrier on=20 to see whether anything would come through in daylight, but nothing = above the=20 noise so far.
 
Thanks very much for offering the = chance for this=20 interesting experiment!
 
Best wishes,
Markus  (DF6NM)

Sent: Friday, September 02, 2011 11:38 AM
Subject: Re: Microhertzing at LF:

Markus, LF,

Your night long transmission appeared = nicely in=20 Haifa http://dl.dropbox.com/u/10280270/4x1rf_DF6NM_QRSS3600_2sept2011.jpg=20
and Bucharest http://dl.dropbox.com/u/10280270/YO/yo4x1rf_DF6NM_QRSS3600_2sept= 2011.jpg

There's=20 room left for using much less power. Based on last night results, a 1mW = EMRP=20 from you should be about the same level as the 137780.29445 Loran trace = in=20 Haifa. It was a good opportunity to test both receivers, looking forward = to=20 further tests.


73s
Chris 4X1RF



On Fri, Sep 2, 2011 at 1:24 AM, Markus Vester = <markusvester@aol.com> = wrote:
trying again...

From: Markus Vester =
Sent: Thursday, September 01, 2011 10:47 PM
Subject: Re: Microhertzing at LF:

Hi Chris,
 
thanks for this! The Saudi Loran = traces (GRI=20 8830) look very accurate on your 4X grabber. I will try to appear = there=20 tonight, and have started to send a straight carrier on = 137780.30. TX=20 power is now reduced to about 100 mW EMRP.
 
Best = 73,
Markus

From: Chris 4X1RF =
Sent: Thursday, September 01, 2011 1:34 PM
To: rsgb_lf_group@blacksheep.org
Subject: Re: Microhertzing at LF:

Markus, LF,

As a newcomer to LF I find this as = an=20 interesting experiment for real low power or long distance tests for = those who=20 can achieve the necessary frequency stability requirements. I found = this to be=20 quite a challenge...

I have followed your initiative and = started=20 similar windows on my grabbers in YO: http://dl.dropbox.com/u/10280270/YO/TA3600.jpg and = 4X: http://dl.dropbox.com/u/10280270/4X/TA3600.jpg
The 4X=20 grabber is currently using the Mercury HPSDR receiver (http://openhpsdr.org) which is=20 GPSDO locked. However, the audio is routed to SpectrumLab using = Virtual Audio=20 Cable as a virtual sound card. I have no info regarding VAC sample = rate=20 accuracy or how I can automatically adjust it so this may be a = limiting=20 factor, further experimentation is needed. In the worst case, a real = sound=20 card could be used but then it also has to be locked to = GPS.

The YO=20 grabber is usually using GQD as a reference for the sound card sample = rate=20 calibration in SpectrumLab and the LF receiver is based on a = laboratory grade=20 VTCXO. GQD being off air, I was forced to use DHO which is not very = reliable=20 during the night for me as can be seen on the 137.775 Loran=20 line.

Thanks for the challenge!


73s
Chris=20 4X1RF

...

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