Return-Path: X-Spam-DCC: paranoid 1481; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-1.7 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_50_60,HTML_MESSAGE,PLING_QUERY,SPF_PASS,UNPARSEABLE_RELAY autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id uA3HcFdA028958 for ; Thu, 3 Nov 2016 18:38:15 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1c2Luj-0006Ez-B2 for rs_out_1@blacksheep.org; Thu, 03 Nov 2016 17:34:57 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1c2Lui-0006Eq-Sl for rsgb_lf_group@blacksheep.org; Thu, 03 Nov 2016 17:34:56 +0000 Received: from nm27-vm3.bullet.mail.ir2.yahoo.com ([212.82.97.54]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.87) (envelope-from ) id 1c2Lug-0008DR-16 for rsgb_lf_group@blacksheep.org; Thu, 03 Nov 2016 17:34:55 +0000 X-DKIM-Result: Domain=yahoo.co.uk Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.co.uk; s=s2048; t=1478194492; bh=aMznmQl3DnvLHv27jRFD5BbFfchc6KhZlkrvA87QrB8=; h=Date:From:Reply-To:To:In-Reply-To:References:Subject:From:Subject; b=cp9DEgeJm58vLdhyTZkcNldfdkJ5q1Pd4OyxuDpm4I3iMVpTQ9CF7WTSesy/8IJT+Ic7pCUbMAetRtQ/qOSAgJpgk0Sjf/NwuHgSpjtO+wn55+UltGe0YFmIw2cfQI2gXKlUi2r88BXGa2oo2e5nWYL272tHfqXz93BxIuzhvM6PrSEqEw20Qm8cBCeO7Bn3E0eDAQ4YKVd9OesAawKW1W+vwXrkgSvtVJAC1nwDspnCCk49uDd7ctDUkycXGuJtVykD9xEX6uajNQ9xxTVIrx8W15GiuAjeuJFFxvRH5pecJpuxuNVNfo/tDF8yrkZndfOJfx+AaFVIn7b8Ki4k+A== Received: from [212.82.98.60] by nm27.bullet.mail.ir2.yahoo.com with NNFMP; 03 Nov 2016 17:34:52 -0000 Received: from [212.82.98.113] by tm13.bullet.mail.ir2.yahoo.com with NNFMP; 03 Nov 2016 17:34:52 -0000 Received: from [127.0.0.1] by omp1050.mail.ir2.yahoo.com with NNFMP; 03 Nov 2016 17:34:52 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 677475.51149.bm@omp1050.mail.ir2.yahoo.com X-YMail-OSG: BMJnq9QVM1l6jzWVJ30Mvq8pyg2NhMABe2ySOeQffLdmxoEWdbdPOeZtk916it9 PMJRbeMgFoUGKJeYkuSGk9f44fsGgrVLxrBL6TQHcTsNMeCQiS7r7z9hl36KrFkYwVSGmn0uChUL hojj54wDwW1NDfyvCStXR572lg2F3AYhqPXv4f9yLdOkRMajb_qZduf2ovoNz7lBs_CaMXaXjNHu 33z5Z4XE2oB2C18mRAhT6n_.18dlj2ONORw2eE2uvzXiYlJQM_UQaSkCByV9Yb2mXrMPbRvt4RD8 It5gG7lvZFnSk9vS9smPSxEfSskCJiPUmZeDNpgzIWcusd_6qUBW4.wuBdktxScEZ318aC7bHaNy tAqcVldjoP5Iv5Qs1KtMSYw9hraF0eqaNhY5yWs1pdhaX4YUXZHcMGWr6x3B1x5ERXrOwRh0chT1 y42MwENI5bAXkifbpqp9NvpDe1Af4UoDfQMcyFaMhME7vFnUXBory4ogR73ST29oZMN7abExc0QA PDZt3U.C_v6Nz_omIrQbFH.eFr.xt7eA- Received: from jws700066.mail.ir2.yahoo.com by sendmailws101.mail.ir2.yahoo.com; Thu, 03 Nov 2016 17:34:52 +0000; 1478194492.292 Date: Thu, 3 Nov 2016 17:34:50 +0000 (UTC) From: David Hine To: "rsgb_lf_group@blacksheep.org" Message-ID: <494474701.1172021.1478194490496@mail.yahoo.com> In-Reply-To: References: <581B3A1F.5060609@posteo.de> <1127299165.1072437.1478190721402@mail.yahoo.com> MIME-Version: 1.0 X-Scan-Signature: 86b6d14137f1f41166b7b27a17921f7a Subject: Re: LF: Smart noise cancelling?!? Content-Type: multipart/alternative; boundary="----=_Part_1172020_30841122.1478194490493" 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.11 Content-Length: 13493 Status: O X-Status: X-Keywords: X-UID: 9372 ------=_Part_1172020_30841122.1478194490493 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hi Alan, I=C2=A0am certain=C2=A0you are correct, but this Tesco set is much= much quieter than my Eton G3, which also has sync detection. There must be= something else too=C2=A0in that Tesco =C2=A39 cheapie -but what is it?? I = know another user of one of these he bought for TMS on R4 LW, and he says i= t's the only LW=C2=A0radio he can use anywhere without any=C2=A0interferenc= e. Perhaps get one before they disappear from the shelves? I bought several= , as=C2=A0they are so cheap, with the view to one day=C2=A0discovering this= radio's 'secret'. I feel this 'secret' could be valuable to know=C2=A0for = other LF applications. Perhaps someone in this group has the answer? Very k= ind regards, David.=C2=A0=C2=A0=C2=A0 From: Alan Melia To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, 3 November 2016, 17:14 Subject: Re: LF: Smart noise cancelling?!? =20 Hi David, what describe (jump to frequency as you tune a station in) sounds= like a little bit of sophisticated radio electronics. It suggests that the= unit employs synchronous detection, somtimes called enhanced sideband dete= ction I think. I=C2=A0dont have details to hand but it would allow a clear = signal to be received in a much narrower receiver bandwidth than the 18kHz = of the=C2=A0bog standard diode detector usually used on cheapies. It also h= as the advantage that it greatly reduces the effects of fading (apparent ov= er-modulation) on the audio quality.=C2=A0=C2=A0It may=C2=A0sound unlikely = at first sight at that price But sophisicated MSF synching clocks are avail= able for about the same price.=C2=A0AlanG3NYK ----- Original Message ----- From: David Hine To: rsgb_lf_group@blackshe= ep.org Sent: Thursday, November 03, 2016 4:32 PM Subject: Re: LF: Smart no= ise cancelling?!?=20 Hi Stefan, Although this is a bit different, but also=C2=A0to do with no= ise, I bought a very cheap kitchen broadcast=C2=A0radio from Tesco for =C2= =A39. It has=C2=A0 Long Wave on it,=C2=A0and I am amazed it is the only LW= =C2=A0radio I have that can receive all the stations that still are on LW w= ithout any background noise=C2=A0once a station is tuned in. It can be main= s powered and next to a computer or TV, and still no=C2=A0local noise!! The= model number of this Tesco kitchen=C2=A0radio=C2=A0is RAD - 113B. On tunin= g to a station, it suddenly 'locks on' to it with a small=C2=A0'jump'. Then= the local noise totally disappears, leaving only the required LW=C2=A0prog= ramme interference free!! Why is this? -could it be the way this very cheap= radio detects the signal? If so, the detection=C2=A0method used in this ch= eap=C2=A0radio would be very useful for LF work, in which local mains noise= is always a big problem. Perhaps someone here=C2=A0also owns this Tesco=C2= =A0radio, and can answer why it is=C2=A0so quiet indoors where all my other= Long Wave (and much more expensive)=C2=A0receivers are all=C2=A0swamped by= local noise when used indoors?? I hope this is useful. Regards, David.=C2= =A0=C2=A0 From: DK7FC To: "rsgb_lf_group@blacksheep.org" =20 Sent: Thursday, 3 November 2016, 13:22 Subject: LF: Smart noise cancelling?!? =20 Hi all, Last night i thought a bit about noise cancelling on LF/VLF. Depending=20 on the band and distance and strength of the QRN, different settings for=20 a noise blanker are used, or optimal. Different rise times, treshold=20 levels and so on. I thought about propagation changes and different shapes of QRN bursts=20 in the time domain, requiring different blanker settings. Is it possible to program an 'intelligent' noise blanking system that is=20 evaluating the input spectrum, looking at the shape/type of a sferic and=20 automatically sets individual dynamic noise blanker parameters for each=20 burst? Or do i miss something here? Just a thought. I guess i'm not the first one who has this idea :-) 73, Stefan =20 ------=_Part_1172020_30841122.1478194490493 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Hi Alan, I am certain you are correct, but this Tesco set is muc= h much quieter than my Eton G3, which also has sync detection. There must b= e something else too in that Tesco =C2=A39 cheapie -but what is it?? I= know another user of one of these he bought for TMS on R4 LW, and he says = it's the only LW radio he can use anywhere without any interferen= ce. Perhaps get one before they disappear from the shelves? I bought severa= l, as they are so cheap, with the view to one day discovering thi= s radio's 'secret'. I feel this 'secret' could be valuable to know for= other LF applications. Perhaps someone in this group has the answer? Very = kind regards, David.   


From: Alan Meli= a <alan.melia@btinternet.com>
To: rsgb_lf_group@blacksheep.org
Sent: Thursday, 3 November 2016, 17:14
Subject: Re: LF: Smart noise can= celling?!?

=
Hi David, what describe (= jump to frequency as you=20 tune a station in) sounds like a little bit of sophisticated radio electron= ics.=20 It suggests that the unit employs synchronous detection, somtimes called=20 enhanced sideband detection I think. I dont have details to hand but i= t=20 would allow a clear signal to be received in a much narrower receiver bandw= idth=20 than the 18kHz of the bog standard diode detector usually used on chea= pies.=20 It also has the advantage that it greatly reduces the effects of fading=20 (apparent over-modulation) on the audio quality.
 
 It may sound unlikely at fi= rst sight at=20 that price But sophisicated MSF synching clocks are available for about the= same=20 price.
 
Alan
G3NYK
----- Original Message -----
From:=20 David=20 Hine
Sent: Thursday, November 03, 2016 = 4:32=20 PM
Subject: Re: LF: Smart noise=20 cancelling?!?

Hi Stefan,=20 Although this is a bit different, but also to do with noise, I bough= t a=20 very cheap kitchen broadcast radio from Tesco for =C2=A39. It has&nb= sp; Long=20 Wave on it, and I am amazed it is the only LW radio I have that= can=20 receive all the stations that still are on LW without any background=20 noise once a station is tuned in. It can be mains powered and next t= o a=20 computer or TV, and still no local noise!! The model number of this = Tesco=20 kitchen radio is RAD - 113B. On tuning to a station, it suddenl= y=20 'locks on' to it with a small 'jump'. Then the local noise totally= =20 disappears, leaving only the required LW programme interference free= !!=20 Why is this? -could it be the way this very cheap radio detects the signa= l? If=20 so, the detection method used in this cheap radio would be very= =20 useful for LF work, in which local mains noise is always a big problem.= =20 Perhaps someone here also owns this Tesco radio, and can answer= why=20 it is so quiet indoors where all my other Long Wave (and much more= =20 expensive) receivers are all swamped by local noise when used= =20 indoors?? I hope this is useful. Regards, David.  

From: DK7FC=20 <selberdenken@posteo.de>
To: "rsgb_lf_group@blacksheep.org"=20 <rsgb_lf_group@blacksheep.org>
Sent:= Thursday, 3 November=20 2016, 13:22
Subject: LF: Smart noise=20 cancelling?!?

Hi=20 all,

Last night i thought a bit abou= t noise cancelling on LF/VLF.=20 Depending
on the band and distance and strength of the= QRN, different=20 settings for
a noise blanker are used, or optimal. Dif= ferent rise times,=20 treshold
levels and so on.
I thought= about propagation changes and=20 different shapes of QRN bursts
in the time domain, req= uiring different=20 blanker settings.

Is it possible to = program an 'intelligent' noise=20 blanking system that is
evaluating the input spectrum,= looking at the=20 shape/type of a sferic and
automatically sets individu= al dynamic noise=20 blanker parameters for each
burst?
O= r do i miss something=20 here?

Just a thought. I guess i'm no= t the first one who has this idea=20 :-)

73,=20 Stefan




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