Message-ID: <473AB65A.40904@online.fr>
Date: Wed, 14 Nov 2007 09:48:26 +0100
From: =?ISO-8859-1?Q?Jean-Pierre_M=E9r=E9?= <jpm.f1afj@online.fr>
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Subject: Re: LF: Re: Re: 136kHz DX 11/12 Nov - DCF39
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Hello Markus , Alan and Mike ,

Here, on the antenna which is in your direction (K9AY) I do not see anything
abnormal ,  but I am further (JN06HT)! to see the screen printing with :=20
http://jpmere.online.fr/Temp/Capt_12.jpg

73 Jean-Pierre f1afj

Markus Vester a =E9crit :
> Hi Mike and Alan,
>
> I believe Mike is right in that the FSK bursts in the upper half of=20
> the band actually do come from DCF39.
>
> Since April 2nd, they have switched to a new Transradio solid state=20
> transmitter, which unfortunately appears to have much less efficient=20
> modulation waveform shaping. The old TX is still used as a backup and=20
> has come on for a few hours from time to time. This is also the reason=20
> for the different reported idle frequencies (138830.03 Hz before,=20
> 138830.6 Hz now).
>
> There is a grabber shot on=20
> http://members.aol.com/df6nm2/QRM/DCF39_sidebands_070404.png which=20
> shows the difference of the spectral characteristics. Especially in=20
> quiet conditions, the new burst sidebands can be seen down to about=20
> 137.1 kHz and do significantly affect QRSS reception here. I have been=20
> in contact with a person at the German regulatory body=20
> "Bundesnetzagentur", who was involved in the on-site acceptance=20
> testing. He was quite understanding and helpful, but basically said=20
> that the emitted spectrum had been confirmed to be within the=20
> prescribed mask, and there was little he could do to enforce a=20
> reduction of the remaining out-of-band emissions.
>
> Due to the modulation characteristics there are however a few spectral=20
> gaps in the sidebands which could be useful to us. The appended plot=20
> shows a spectrogram between 137.5 and 137.8 kHz (audio frequencies=20
> above 135.5 kHz zero beat). The vertical streaks show visible minima at
>  137.762 to 137.773 kHz (shown as 2262 to 2273 Hz),
>  137.620 to 137.655 kHz, and
>  137.560 to 137.575 kHz.
> One possible suggestion would be to move our activity regions for TA=20
> (currently ~137.778) and QRSS (~137.700) down into the first two gaps.=20
> Before we decide to change our habits, it would be interesting to know=20
> how much others in the LF group are affected.
>
> 73 and best wishes
> Markus, DF6NM
>
> PS: A strong blue trace appeared near 136.319 around 19:20 - Mike's=20
> test signal?
>
>
> ----- Original Message -----
> From: "Alan Melia" <alan.melia@btinternet.com=20
> <mailto:alan.melia@btinternet.com>>
> To: <rsgb_lf_group@blacksheep.org <mailto:rsgb_lf_group@blacksheep.org>>
> Sent: Monday, November 12, 2007 7:16 PM
> Subject: LF: Re: 136kHz DX 11/12 Nov
>
>
> > Hi Mike I think the data bursts are actually probably from Lakihegy
> > (Budapest) 135.5 or thereabouts, which is very strong at night and=20
> shifts
> > "into" the band a couple of hundred Hz.
> > Loran from Rugby went off in July and it has been a lot quieter=20
> since then,
> > but it doesnt seem to be fully running 24/7 yet at Anthorn.
> >
> > Alan G3NYK
> >
> > ----- Original Message -----
> > From: "Mike Dennison" <mike.dennison@ntlworld.com=20
> <mailto:mike.dennison@ntlworld.com>>
> > To: <rsgb_lf_group@blacksheep.org <mailto:rsgb_lf_group@blacksheep.org>>
> > Sent: Monday, November 12, 2007 6:06 PM
> > Subject: LF: 136kHz DX 11/12 Nov
> >
> >> I have at last got my station fully running again. Having been off
> >> the air for a few months I notice much less Loran QRM which will make
> >> CW contacts possible again. But more QRM from DCF39 data bursts which
> >> makes QRSS harder.
> >>
> >> Monitored last night and received the following (using Argo set to
> >> 30s slow) :
> >>
> >> 1800 - 1850 Unidentified station on 137.776kHz (who?)
> >> 1900 - 2000 UA4WPF 137.777.2kHz, 'O'
> >> 0610 - 0700 XKO 137.777.4kHz One complete call, 'O'
> >>
> >> Very noisy overnight.
> >>
> >> Will test my beacon on 136.318.7kHz this evening, but not overnight.
> >> Hope to run an overnight beacon later this week. Please let me know
> >> if this frequency causes anyone a problem.
> >>
> >> de Mike, G3XDV
> >> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> >>
>
> ------------------------------------------------------------------------
>

--=20
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