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=2.7 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, FORGED_MUA_OUTLOOK,HTML_40_50,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 uA3HIYB1028886 for ; Thu, 3 Nov 2016 18:18:34 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1c2Lar-00061v-Fs for rs_out_1@blacksheep.org; Thu, 03 Nov 2016 17:14:25 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1c2Laq-00061l-Sd for rsgb_lf_group@blacksheep.org; Thu, 03 Nov 2016 17:14:24 +0000 Received: from rgout0106.bt.lon5.cpcloud.co.uk ([65.20.0.126] helo=rgout01.bt.lon5.cpcloud.co.uk) by relay1.thorcom.net with esmtp (Exim 4.87) (envelope-from ) id 1c2Lao-000852-3y for rsgb_lf_group@blacksheep.org; Thu, 03 Nov 2016 17:14:23 +0000 X-OWM-Source-IP: 86.178.51.135 (GB) X-OWM-Env-Sender: alan.melia@btinternet.com X-Junkmail-Premium-Raw: score=12/50,refid=2.7.2:2016.11.3.165116:17:12.731,ip=,rules=__HAS_MSGID, __SANE_MSGID, MSGID_32HEX_LC, INVALID_MSGID_NO_FQDN, __MSGID_32HEX, __HAS_FROM, __FRAUD_WEBMAIL_FROM, __TO_MALFORMED_2, __TO_NO_NAME, __REFERENCES, __BOUNCE_CHALLENGE_SUBJ, __BOUNCE_NDR_SUBJ_EXEMPT, __MIME_VERSION, __CT, __CTYPE_MULTIPART_ALT, __CTYPE_HAS_BOUNDARY, __CTYPE_MULTIPART, __HAS_X_PRIORITY, __HAS_MSMAIL_PRI, __HAS_X_MAILER, USER_AGENT_OE, __OUTLOOK_MUA_1, __USER_AGENT_MS_GENERIC, __MIME_TEXT_P2, __MIME_TEXT_H2, __ANY_URI, __FRAUD_BODY_WEBMAIL, __URI_NO_WWW, __FRAUD_MONEY_CURRENCY_POUND, __FRAUD_MONEY_BIG_COIN_DIG, __SUBJ_ALPHA_NEGATE, __INT_PROD_TV, SUPERLONG_LINE, __HTML_BOLD, __HTML_AHREF_TAG, __HAS_HTML, HTML_TAG_NAME_RND_CAP, __HTML_TAG_DIV, HTML_NO_HTTP, BODYTEXTH_SIZE_3000_MORE, BODYTEXTH_SIZE_10000_LESS, __MIME_TEXT_H1, __MIME_TEXT_P1, __MIME_HTML, __TAG_EXISTS_HTML, __FRAUD_MONEY_CURRENCY, __FRAUD_MONEY_BIG_COIN, __FRAUD_MONEY_VALUE, __FRAUD_MONEY, __FRAUD_WEBMAIL, __OUTLOOK_MUA, __MIME_TEXT_H, __MIME_TEXT_P, FORGED_MUA_OUTLOOK, REFERENCES, NO_URI_HTTPS Received: from gnat (86.178.51.135) by rgout01.bt.lon5.cpcloud.co.uk (9.0.019.07.01-1) (authenticated as alan.melia@btinternet.com) id 581B44720004D63D for rsgb_lf_group@blacksheep.org; Thu, 3 Nov 2016 17:14:20 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btinternet.com; s=btcpcloud; t=1478193262; bh=EiwdxrJ36zV77bXm0qwpnvdFQ16zQwiFiY3UZ19QugU=; h=Message-ID:From:To:References:Subject:Date:MIME-Version:X-Mailer; b=YiFEuXyVod6ST/cQC3DywslUPgwyhekGdVetdIztggK/CEmHPZShEjJb9HbyuTeo7FNwJ2q0TRdMEm8UtQ8V/9YNNBVZ5M8JeWEMUR8MCrJHgB+vgwCr569C/W7IktAw4qGyX0ERlltwY6XOFKhaMbS8bjLb/nXtzRF7SnydgSU= Message-ID: From: "Alan Melia" To: References: <581B3A1F.5060609@posteo.de> <1127299165.1072437.1478190721402@mail.yahoo.com> Date: Thu, 3 Nov 2016 17:14:09 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 X-Scan-Signature: edae4bc128aa121544439b7b7cfd26a1 Subject: Re: LF: Smart noise cancelling?!? Content-Type: multipart/alternative; boundary="----=_NextPart_000_0027_01D235F5.B07CE340" 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: 9429 Status: O X-Status: X-Keywords: X-UID: 9370 This is a multi-part message in MIME format. ------=_NextPart_000_0027_01D235F5.B07CE340 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable 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 = allow 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 -----=20 From: David Hine=20 To: rsgb_lf_group@blacksheep.org=20 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 has Long Wave on it, and I am amazed it is the only LW = radio I have that can receive 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 is 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 way this very cheap = radio detects the signal? If so, the detection method used in this cheap = radio would be very useful for LF work, in which local mains 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. =20 -------------------------------------------------------------------------= ----- From: DK7FC To: "rsgb_lf_group@blacksheep.org" =20 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=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 = 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 ------=_NextPart_000_0027_01D235F5.B07CE340 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF
Hi David, what describe (jump to = frequency as you=20 tune a station in) sounds like a little bit of sophisticated radio = electronics.=20 It suggests that the unit employs synchronous detection, somtimes called = enhanced sideband detection I think. I dont have details to hand = but it=20 would allow a clear signal to be received in a much narrower receiver = bandwidth=20 than the 18kHz of the bog standard diode detector usually used on = cheapies.=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 = first 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 = bought a=20 very cheap kitchen broadcast radio from Tesco for =C2=A39. It = has  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 to 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 = suddenly=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 = signal? 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 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 = times,=20 treshold
levels and so on.
I thought about propagation changes = and=20 different shapes of QRN bursts
in the time domain, requiring = 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 individual dynamic = noise=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 = this idea=20 :-)

73,=20 Stefan



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