Return-Path: Received: from mtain-mc06.r1000.mx.aol.com (mtain-mc06.r1000.mx.aol.com [172.29.96.78]) by air-dd02.mail.aol.com (v129.4) with ESMTP id MAILINDD024-86aa4d04d8d533c; Sun, 12 Dec 2010 09:14:45 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mc06.r1000.mx.aol.com (Internet Inbound) with ESMTP id B0570380000EE; Sun, 12 Dec 2010 09:14:41 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PRmg8-0000wR-Ff for rs_out_1@blacksheep.org; Sun, 12 Dec 2010 14:13:32 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PRmg7-0000wI-Sp for rsgb_lf_group@blacksheep.org; Sun, 12 Dec 2010 14:13:31 +0000 Received: from imr-db03.mx.aol.com ([205.188.91.97]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1PRmg5-0003eF-04 for rsgb_lf_group@blacksheep.org; Sun, 12 Dec 2010 14:13:31 +0000 Received: from mtaout-db05.r1000.mx.aol.com (mtaout-db05.r1000.mx.aol.com [172.29.51.197]) by imr-db03.mx.aol.com (8.14.1/8.14.1) with ESMTP id oBCEDIGa025955 for ; Sun, 12 Dec 2010 09:13:18 -0500 Received: from White (nrbg-4d073628.pool.mediaWays.net [77.7.54.40]) by mtaout-db05.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id 2519CE0000A7 for ; Sun, 12 Dec 2010 09:13:11 -0500 (EST) Message-ID: From: "Markus Vester" To: Date: Sun, 12 Dec 2010 15:13:44 +0100 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-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: New Eu slot 136.177 kHz? Content-Type: multipart/alternative; boundary="----=_NextPart_000_001F_01CB9A0F.2AA674D0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.1 required=5.0 tests=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: 3039ac1d604e4d04d8d10d98 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none ------=_NextPart_000_001F_01CB9A0F.2AA674D0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Dear LF, after considerations with Scott VE7TIL, Mike G3XDV, and Laurence KL7UK= , I would like to discuss moving the European intercontinental transmi= t slot. It is currently centered on 136.320 kHz, and I propose a new= center frequency of 136.177 kHz. This discussion was initiated by VE7TIL, who is plagued by severe QRM= lines, to an amount that he considers the vicinity of 136.32 kHz as= being unusable for him. Scott believes that the interference is cause= d by a PLC system leaking from a nearby powerline, and that it will pr= obably not be possible to fix it locally. Of course it can be disputed= whether QRM at one receive site would be reason enough to change a ba= nd plan, which has been useful for a number of years. On the other han= d, there is only a limited number of receivers around the world. And= we would certainly like to have Scott onboard, as the path from Eu to= the American West coast is certainly one of the most challenging ones= . A few years ago, we decided to move Eu transmissions from the original= 135922 Hz to 136320 Hz, driven by a wider gap in the American Loran-C= line spectrum. Since the shutdown of US and Canadian Loran chains, th= is is no longer an issue. One benefit of going back to a lower frequency would be moving further= away from the Canadian military transmitter CFH, which occasionally= sends out a strong FSK (or MSK) signal centered on 137.0 kHz. It woul= d be interesting to get some information how much this one actually af= fects the American LF background at different frequency offsets. Here in Europe and Russia, a possible disadvantage of going down is th= at we would also come closer to HGA22. This is the 100 kW telecontrol= transmitter in Budapest, an idle carrier sitting at 135.43 kHz, and= excursions to 135.77 during FSK bursts. Normally these bursts appear= every 11 seconds, but at times there are annoying blocks of consecuti= ve telegrams several minutes long. Here in Bavaria, the FSK modulation= sidebands are visibe up to about 136.5 kHz, but there are pronounced= spectral gaps due to the 200 bd modulation. These clear gaps are near= 135.97, 136.17 and 136.37 kHz.=20 We looked at 136.37 first, but this would not fix the problem for Scot= t. 135.97 seems worse in Europe due to Luxembourg effect impressed on= HGA, and is also getting close to the Greek military SXV. So we decid= ed to focus on 136.17 kHz. A closer look revealed that this very usefu= l FSK minimum is actually centered on 136177 Hz, and about 8 Hz wide. For the last few days, I have been running my grabber http://www.alice= -dsl.net/df6nm/grabber/Grabber.htm with a split window, showing both= the present and the proposed new slot side by side. The direct modula= tion sidebands (showing as red bands) are much better on the new frequ= ency. Nighttime Luxembourg QRM generally does not appear to be worse,= despite being closer to the HGA carrier. We also expect the latter to= be a more regionally confined effect, which will not be present in re= mote areas of the world. After all, the main purpose of Eu-slot grabbe= rs within Euroupe would not so much be ultimate sensitivity, but rathe= r to provide a monitor for intra-Eu transmit frequency coordination,= and a comparison log for verification of DX receptions.=20 Before coming to a possible decision to move the Eu frequency band, we= would like to collect some feedback on the receive situation in diffe= rent parts of the world. Traditionally, Eu slot transmissions were pri= marily targeted towards the American east coast. But of course we woul= d like to include other areas of the world. How useful would the propo= sed slot be for example in Russia or Japan?=20 Active Loran-C rates in Japan are GRI 8930 (lines at 136175.812 and 13= 68181.411 Hz) and GRI 9930 (lines at 136173.212 and 136178.248 Hz).= Russia uses GRI 8000 with lines at 6.25 Hz multiples, and perhaps GRI= 7950 (136178.157 Hz). As the frequencies are very accurate, these lin= es are very useful calibration markers. Now, your opinions please! Best regards, Markus (DF6NM) ------=_NextPart_000_001F_01CB9A0F.2AA674D0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Dear LF,
 
after con= siderations with=20 Scott VE7TIL, Mike G3XDV, and Laurence KL7UK, I would like=20 to discuss moving the European intercontinental transmit slot. It= =20 is currently centered on 136.320 kHz, and I propose a= new center=20 frequency of 136.177 kHz.
 
This discussion was initiat= ed by VE7TIL,=20 who is plagued by severe QRM lines, to an amount that he consider= s the=20 vicinity of 136.32 kHz as being unusable for him. Scott believes= =20 that the interference is caused by a PLC system leaking= from a=20 nearby powerline, and that it will probably not be possible to fi= x it=20 locally. Of course it can be disput= ed whether QRM=20 at one receive site would be reason enough to change a band plan,= which has=20 been useful for a number of years. On the other hand, there is on= ly a=20 limited number of receivers around the world. And we would= certainly=20 like to have Scott onboard, as the path from Eu to the American West= coast is=20 certainly one of the most challenging ones.
 
A few years ago, we decided to move= Eu=20 transmissions from the original 135922 Hz to 136320 Hz, driven by=  a=20 wider gap in the American Loran-C line spectrum. Since the shutdown of= US and=20 Canadian Loran chains, this is no longer an issue.
 
One benefit of going back to a= lower frequency=20 would be moving further away from the Canadian military transmitter CF= H, which=20 occasionally sends out a strong FSK (or MSK) signal centered on 137.0= kHz. It=20 would be interesting to get some information how much this one ac= tually=20 affects the American LF background at different frequency offsets.
 
Here in Europe and Russia, a pos= sible=20 disadvantage of going down is that we would also come closer to HGA22.= This is=20 the 100 kW telecontrol transmitter in Budapest, an idle carrier= sitting at=20 135.43 kHz, and excursions to 135.77 during FSK bursts. Normally= these=20 bursts appear every 11 seconds, but at times there are annoying= blocks of=20 consecutive telegrams several minutes long. Here in Bavaria, the = FSK=20 modulation sidebands are visibe up to about 136.5 kHz, but there= are=20 pronounced spectral gaps due to the 200 bd modulation. These clea= r gaps=20 are near 135.97, 136.17 and 136.37 kHz.
 
We looked at 136.37 first,= but this would=20 not fix the problem for Scott. 135.97 seems worse in Europe due to Lux= embourg=20 effect impressed on HGA, and is also getting close to the Greek milita= ry SXV. So=20 we decided to focus on 136.17 kHz. A=20 closer look revealed that this very useful FSK=20 minimum is actually centered on 136177 Hz, and about 8 Hz=20 wide.
 
For the last few days, I have been ru= nning my=20 grabber http://www.alice-dsl.n= et/df6nm/grabber/Grabber.htm=20 with a split window, showing both the present and the proposed ne= w slot=20 side by side. The direct modulation sidebands (showing as red ban= ds) are=20 much better on the new frequency. Nighttime Luxembourg QRM genera= lly does=20 not appear to be worse, despite being closer to the HGA=20 carrier. We also expect the latter to be a more regionally= =20 confined effect, which will not be present in remote areas= of the=20 world. After all, the main purpose of Eu-slot grabbers within Euroupe= would=20 not so much be ultimate sensitivity, but rather to provide a moni= tor for=20 intra-Eu transmit frequency coordination, and a comparison log for ver= ification=20 of DX receptions.
 
Before coming to a possible decision to move the Eu frequency ban= d, we=20 would like to collect some feedback on the receive situation in differ= ent parts=20 of the world. Traditionally, Eu slot transmissions were primarily= targeted=20 towards the American east coast. But of course we would like= =20 to include other areas of the world. How useful would the pr= oposed=20 slot be for example in Russia or Japan?
 
Active Loran-C rates in Japan are GRI 8930 (lines at 136175.= 812 and=20 1368181.411 Hz) and GRI 9930 (lines at  136173.212 and 136178.248= Hz).=20 Russia uses GRI 8000 with lines at 6.25 Hz multiples, and pe= rhaps GRI=20 7950 (136178.157 Hz). As the frequencies are very accurate, these line= s=20 are very useful calibration markers.
 
Now, your opinions please!
 
Best regards,
Markus (DF6NM)
 
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