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 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 uA3HP9nC028906 for ; Thu, 3 Nov 2016 18:25:09 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1c2Li9-000682-O0 for rs_out_1@blacksheep.org; Thu, 03 Nov 2016 17:21:57 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1c2Li9-00067t-93 for rsgb_lf_group@blacksheep.org; Thu, 03 Nov 2016 17:21:57 +0000 Received: from mail-wm0-x230.google.com ([2a00:1450:400c:c09::230]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.87) (envelope-from ) id 1c2Li6-00088I-HB for rsgb_lf_group@blacksheep.org; Thu, 03 Nov 2016 17:21:56 +0000 Received: by mail-wm0-x230.google.com with SMTP id p190so515802wmp.1 for ; Thu, 03 Nov 2016 10:21:54 -0700 (PDT) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=YPQ5kQsdv0uIuBU2LT6Ec0UsELCi5gmLm+E7ur7XEjU=; b=XUdp2id4CC7eUtqurUeLdEmORsqqR/W+t/hvi0h+1/uKimn12lJBe35ASzweK61j4D 7i/3xJvJoCtHfhbonwqbGeDwPMonfrd9HZz0oa+lzPiyka39bQJtoljli7O60Wns8ypF KKG5AcFdDHGogvjAEYWCWoeHPw5RBdgYXNaLS+ujnVYbPfm1SJWAltdLZjoQEcw7tKft jxhKxbRm5HUR8qa6+JKYAr3CzCHHUHkBH7GLi8HlDREnAJypRPfHMm9tJPIFfQiKPR1s Z6tNbzJun/nrpp1dgu1W9FpsLlQAw6NJqkG199SDtl5cYH7rd2b23Br0dsHhUTVGztwQ mT/g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=YPQ5kQsdv0uIuBU2LT6Ec0UsELCi5gmLm+E7ur7XEjU=; b=mkz5U+zdm+/cyKbJ6dWwcYK2Pc9tls3lAT094mE/fowi3aliLd9OFNe5dzvpUh9CEG gtJ5wqQOnJ9LHhoFD1AQRzXqhKM0ukgyo7jgO/C1MBdiud/82YDIlUAJcGrGyMrFQEo+ gEn8pYLLjcqIqUffawFszGlOeHuh6VaDOlOGcyX07d+OYpcABMVR/Ju3VNWIN4haUZgu klQGEhVPQ8ZUZH4l0IE6RVSnrLs8avuBOfLHJrOtq/tNJDI4wcljq5xWj/9oAV9BPcPM +Bzi9c53D9dqfvdhf2nRLN/jdcaJ0SaLSbr9Y2XaKmlyt107HPqTEGA5bxCv/IFZf4H0 AJ+A== X-Gm-Message-State: ABUngvdcfqM4Wg7emYbgDcg9Co1CIM1Dt7qAx8fQ0VI2U10emsQjwUKFkepryssERF4mItAStJGB2g0jJQqciQ== X-Received: by 10.28.175.77 with SMTP id y74mr3026799wme.114.1478193712726; Thu, 03 Nov 2016 10:21:52 -0700 (PDT) MIME-Version: 1.0 Received: by 10.28.209.74 with HTTP; Thu, 3 Nov 2016 10:21:52 -0700 (PDT) In-Reply-To: References: <581B3A1F.5060609@posteo.de> <1127299165.1072437.1478190721402@mail.yahoo.com> From: Andy Talbot Date: Thu, 3 Nov 2016 17:21:52 +0000 Message-ID: To: rsgb_lf_group@blacksheep.org X-Scan-Signature: 80dfd4418e586cee7526d670ae10acbc Subject: Re: LF: Smart noise cancelling?!? Content-Type: multipart/alternative; boundary=001a11439b2e2807b9054068cb23 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: 10456 Status: O X-Status: X-Keywords: X-UID: 9371 --001a11439b2e2807b9054068cb23 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Could it just be that it tunes in 9kHz steps? So will jump stright onto frequency A low cost radio is sure to have a completely digital front end. 'jnt On 3 November 2016 at 17:14, Alan Melia wrote: > 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 detection I think. I dont have details to hand but it would allo= w > a clear signal to be received in a much narrower receiver bandwidth than > the 18kHz of the bog standard diode detector usually used on cheapies. It > also has the advantage that it greatly reduces the effects of fading > (apparent over-modulation) on the audio quality. > > It may sound unlikely at first sight at that price But sophisicated MSF > synching clocks are available for about the same price. > > Alan > G3NYK > > ----- Original Message ----- > *From:* David Hine > *To:* rsgb_lf_group@blacksheep.org > *Sent:* Thursday, November 03, 2016 4:32 PM > *Subject:* Re: LF: Smart noise cancelling?!? > > Hi Stefan, Although this is a bit different, but also to do with noise, I > bought a very cheap kitchen broadcast radio from Tesco for =C2=A39. It ha= s Long > Wave on it, and I am amazed it is the only LW radio I have that can recei= ve > all the stations that still are on LW without any background noise once a > station is tuned in. It can be mains powered and next to a computer or TV= , > and still no local noise!! The model number of this Tesco kitchen radio i= s > RAD - 113B. On tuning to a station, it suddenly 'locks on' to it with a > small 'jump'. Then the local noise totally disappears, leaving only the > required LW programme interference free!! Why is this? -could it be the w= ay > this very cheap radio detects the signal? If so, the detection method use= d > in this cheap radio would be very useful for LF work, in which local main= s > noise is always a big problem. Perhaps someone here also owns this > Tesco radio, and can answer why it is so quiet indoors where all my other > Long Wave (and much more expensive) receivers are all swamped by local > noise when used indoors?? I hope this is useful. Regards, David. > > ------------------------------ > *From:* DK7FC > *To:* "rsgb_lf_group@blacksheep.org" > *Sent:* Thursday, 3 November 2016, 13:22 > *Subject:* LF: Smart noise cancelling?!? > > Hi all, > > Last night i thought a bit about noise cancelling on LF/VLF. Depending > on the band and distance and strength of the QRN, different settings for > a noise blanker are used, or optimal. Different rise times, treshold > levels and so on. > I thought about propagation changes and different shapes of QRN bursts > in the time domain, requiring different blanker settings. > > Is it possible to program an 'intelligent' noise blanking system that is > evaluating the input spectrum, looking at the shape/type of a sferic and > automatically sets individual dynamic noise blanker parameters for each > burst? > Or do i miss something here? > > Just a thought. I guess i'm not the first one who has this idea :-) > > 73, Stefan > > > > --001a11439b2e2807b9054068cb23 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Could it just be that it tunes in 9kHz steps? So will jump= stright onto frequency
A low cost radio is sure to have a completely d= igital front end.

'jnt


On 3 November = 2016 at 17:14, Alan Melia <alan.melia@btinternet.com> wrote:
Hi David, what describe (jump to frequ= ency 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=C2=A0dont 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=C2=A0bog 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.
=C2=A0
=C2=A0It may=C2=A0sound unlikely at fi= rst sight at=20 that price But sophisicated MSF synching clocks are available for about the= same=20 price.
=C2=A0
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=C2=A0to do with noise, I bough= t a=20 very cheap kitchen broadcast=C2=A0radio from Tesco for =C2=A39. It has=C2= =A0 Long=20 Wave on it,=C2=A0and I am amazed it is the only LW=C2=A0radio I have that= can=20 receive all the stations that still are on LW without any background=20 noise=C2=A0once a station is tuned in. It can be mains powered and next t= o a=20 computer or TV, and still no=C2=A0local noise!! The model number of this = Tesco=20 kitchen=C2=A0radio=C2=A0is RAD - 113B. On tuning to a station, it suddenl= y=20 'locks on' to it with a small=C2=A0'jump'. Then the local= noise totally=20 disappears, leaving only the required LW=C2=A0programme interference free= !!=20 Why is this? -could it be the way this very cheap radio detects the signa= l? If=20 so, the detection=C2=A0method used in this cheap=C2=A0radio would be very= =20 useful for LF work, in which local mains noise is always a big problem.= =20 Perhaps someone here=C2=A0also owns this Tesco=C2=A0radio, and can answer= why=20 it is=C2=A0so quiet indoors where all my other Long Wave (and much more= =20 expensive)=C2=A0receivers are all=C2=A0swamped by local noise when used= =20 indoors?? I hope this is useful. Regards, David.=C2=A0=C2=A0

From: DK7FC=20 <selberden= ken@posteo.de>
To:= "rs= gb_lf_group@blacksheep.org"=20 <rsg= b_lf_group@blacksheep.org>
Sent: Thur= sday, 3 November=20 2016, 13:22
Subject: LF: Smart noise=20 cancelling?!?

Hi=20 all,

Last night i thought a bit about 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. Different rise tim= es,=20 treshold
levels and so on.
I thought about propagation changes and= =20 different shapes of QRN bursts
in the time domain, requiring differen= t=20 blanker settings.

Is it possible to program an 'intelligent= 9; noise=20 blanking system that is
evaluating the input spectrum, looking at the= =20 shape/type of a sferic and
automatically sets individual dynamic nois= e=20 blanker parameters for each
burst?
Or do i miss something=20 here?

Just a thought. I guess i'm not the first one who has th= is idea=20 :-)

73,=20 Stefan




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