Message-ID: <003d01cbd5fa$5c46b870$8cd9160a@EFREMOV>
From: "rn3agc" <rn3agc@mail.ru>
To: <rsgb_lf_group@blacksheep.org>
References: <fda.7c41c1e.3a36327b@UNKNOWN> <e5b.b83817a.3a899eae@UNKNOWN> <8CDA22B19CD407E-1FB0-820@Webmail-m108.sysops.aol.com> <001801cbd5f7$6e7f0e50$8cd9160a@EFREMOV>
Date: Sun, 27 Feb 2011 00:15:46 +0300
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Subject: LF: Re: Proposed Eu waterhole center 136.172 kHz
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I have temporarily made loading of Eu-images more often, each 15 minut=
es.

----- Original Message -----=20
From: "rn3agc" <rn3agc@mail.ru>
To: <rsgb_lf_group@blacksheep.org>
Sent: Saturday, February 26, 2011 11:54 PM
Subject: LF: Re: Proposed Eu waterhole center 136.172 kHz


> Hello Markus, LF,
>
> At 23.00z I want to move an Eu-window of my grabber on "new"
> frequencies, with the center 136.172 khz.
>
> If someone is interested in control of the transmitting on "old"=20
> frequencies
> at this night, please inform. I will make display of concrete necess=
ary
> frequency in a small window.
>
> 73
> Andrey
>
>
>
>
> Dear LF,
>
> after some detailed investigation of the interference situation at=
 W1VD=20
> and
> VE7TIL, we propose to move down the recommended Eu TX slot by 5 Hz,=
 from=20
> the
> current center frequency 136177 to 136172 Hz. The latter seems to be=
 clear
> for Jay within about +-4 Hz (ie 136168 to 136176 Hz). HGA sidebands=
 in
> Europe are no worse as we are still within their spectral gap.
>
> I would ask all interested receive stations to include this range in=
 their
> observations, and look for possible interference at this QRG. If no=
=20
> serious
> problem pops up, we could all shift our grabber slots.
>
> Best 73,
> MArkus (DF6NM)
>
>
> -----Urspr=C3=BCngliche Mitteilung-----=20
> Von: Markus Vester <markusvester@aol.com>
> An: rsgb_lf_group@blacksheep.org
> Verschickt: So., 13. Feb. 2011, 21:53
> Thema: Re: New Eu slot 136.177 kHz?
>
>
>
> Dear LF group,
>
> the considerations which led to the choice of a new Eu waterhole hav=
e been
> explained in a posting from Dec 12th, attached beneath. Here's a bri=
ef
> summary of the current situation:
>
> - We clearly need separate E-W and W-E slots, due to side effects of=
 noise
> blanking, and imperfections of transmitters and receivers.
>
> - The Canadian West coast (Scott, Steve) experiences wide-area=20
> interference
> (presumably PLC), centered on 135700 and 136320. This is what trigge=
red=20
> the
> search for an alternative Eu slot.
>
> - Central and Eastern Europe suffers from HGA22 sidebands, except fo=
r a=20
> few
> narrow slots (135.975, 136.177, 136.38) . The density of FSK telegra=
ms on
> DCF39 and HGA22 has been increasing.
>
> - We want to stay far enough from 137.0 in case CFH would be fired=
 up more
> regularly.
>
>
> - But we now have the problem that Jay is affected by local QRM arou=
nd
> 136.177. It consists.predominantly of a group of unstable lines, spa=
ced by
> about 1 Hz.
>
> I had secretly hoped that Jay might ultimately find a way to identif=
y and
> fix the problem locally, but this may simply not be feasible. How fa=
r up=20
> and
> down does this interference extend in frequency? I'm also not sure=
 whether
> Warren is actually having the same difficulty or not.
>
>
> Now we have the dilemma that if we stay on the new slot, we may loos=
e many
> excellent high-quality observations from Jay. If we move back to the=
 old
> one, we give away the slim chance of being picked up by Scott or his=
=20
> friends
> during that special Transpolar night.
>
> The best choice may be to move on again. If we decide so, we will th=
en=20
> need
> to collect information regarding bad and good channels from all key=
=20
> players,
> perhaps by detailed analysis of wav recordings of the whole lower pa=
rt of
> the band.
>
> Best regards,
> Markus (DF6NM)
>
>
>
>
>
>
> From: Markus Vester
> Sent: Sunday, December 12, 2010 3:13 PM
> To: rsgb_lf_group@blacksheep.org
> Subject: New Eu slot 136.177 kHz?
>
>
>
> Dear LF,
>
> after considerations with Scott VE7TIL, Mike G3XDV, and Laurence KL7=
UK, I
> would like to discuss moving the European intercontinental transmit=
 slot.=20
> It
> is currently centered on 136.320 kHz, and I propose a new center fre=
quency
> of 136.177 kHz.
>
> This discussion was initiated by VE7TIL, who is plagued by severe QR=
M=20
> lines,
> to an amount that he considers the vicinity of 136.32 kHz as being=
=20
> unusable
> for him. Scott believes that the interference is caused by a PLC sys=
tem
> leaking from a nearby powerline, and that it will probably not be po=
ssible
> to fix it locally. Of course it can be disputed whether QRM at one=
 receive
> site would be reason enough to change a band plan, which has been us=
eful=20
> for
> a number of years. On the other hand, there is only a limited number=
 of
> receivers around the world. And we would certainly like to have Scot=
t
> onboard, as the path from Eu to the American West coast is certainly=
 one=20
> of
> the most challenging ones.
>
> A few years ago, we decided to move Eu transmissions from the origin=
al
> 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, this=
 is no
> longer an issue.
>
> One benefit of going back to a lower frequency would be moving furth=
er=20
> away
> from the Canadian military transmitter CFH, which occasionally sends=
 out a
> strong FSK (or MSK) signal centered on 137.0 kHz. It would be intere=
sting=20
> to
> get some information how much this one actually affects the American=
 LF
> background at different frequency offsets.
>
> Here in Europe and Russia, a possible disadvantage of going down is=
 that=20
> we
> would also come closer to HGA22. This is the 100 kW telecontrol=20
> transmitter
> in Budapest, an idle carrier sitting at 135.43 kHz, and excursions=
 to=20
> 135.77
> during FSK bursts. Normally these bursts appear every 11 seconds, bu=
t at
> times there are annoying blocks of consecutive telegrams several min=
utes
> 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.
>
> We looked at 136.37 first, but this would not fix the problem for Sc=
ott.
> 135.97 seems worse in Europe due to Luxembourg effect impressed on=
 HGA,=20
> and
> is also getting close to the Greek military SXV. So we decided to fo=
cus on
> 136.17 kHz. A closer look revealed that this very useful 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 wind=
ow,
> showing both the present and the proposed new slot side by side. The=
=20
> direct
> modulation sidebands (showing as red bands) are much better on the=
 new
> frequency. 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 remote=
 areas
> of the world. After all, the main purpose of Eu-slot grabbers within=
=20
> Euroupe
> would not so much be ultimate sensitivity, but rather to provide a=
 monitor
> for intra-Eu transmit frequency coordination, and a comparison log=
 for
> verification of DX receptions.
>
> Before coming to a possible decision to move the Eu frequency band,=
 we=20
> would
> like to collect some feedback on the receive situation in different=
 parts=20
> of
> the world. Traditionally, Eu slot transmissions were primarily targe=
ted
> towards the American east coast. But of course we would like to incl=
ude
> other areas of the world. How useful would the proposed slot be for=
=20
> example
> in Russia or Japan?
>
> Active Loran-C rates in Japan are GRI 8930 (lines at 136175.812 and
> 1368181.411 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 GR=
I 7950
> (136178.157 Hz). As the frequencies are very accurate, these lines=
 are=20
> very
> useful calibration markers.
>
> Now, your opinions please!
>
> Best regards,
> Markus (DF6NM)
>
>
>
>=20