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 uA3KvKc9029636 for ; Thu, 3 Nov 2016 21:57:20 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1c2P0m-0007z5-D6 for rs_out_1@blacksheep.org; Thu, 03 Nov 2016 20:53:24 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1c2P0m-0007yw-2n for rsgb_lf_group@blacksheep.org; Thu, 03 Nov 2016 20:53:24 +0000 Received: from rgout0306.bt.lon5.cpcloud.co.uk ([65.20.0.212] helo=rgout03.bt.lon5.cpcloud.co.uk) by relay1.thorcom.net with esmtp (Exim 4.87) (envelope-from ) id 1c2P0j-00011K-HX for rsgb_lf_group@blacksheep.org; Thu, 03 Nov 2016 20:53:23 +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=2.7.2:2016.11.3.203017:17:12.731,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, __SUBJ_ALPHA_NEGATE, SUPERLONG_LINE, __HTML_AHREF_TAG, __HAS_HTML, HTML_TAG_NAME_RND_CAP, __HTML_TAG_DIV, HTML_NO_HTTP, BODYTEXTP_SIZE_3000_LESS, BODYTEXTH_SIZE_3000_MORE, BODY_SIZE_6000_6999, BODYTEXTH_SIZE_10000_LESS, __MIME_TEXT_H1, __MIME_TEXT_P1, __MIME_HTML, __TAG_EXISTS_HTML, __URI_NS, __FRAUD_WEBMAIL, __OUTLOOK_MUA, __MIME_TEXT_H, __MIME_TEXT_P, FORGED_MUA_OUTLOOK, REFERENCES, BODY_SIZE_7000_LESS, NO_URI_HTTPS Received: from gnat (86.178.51.135) by rgout03.bt.lon5.cpcloud.co.uk (9.0.019.07.01-1) (authenticated as alan.melia@btinternet.com) id 581B45AB000B660F for rsgb_lf_group@blacksheep.org; Thu, 3 Nov 2016 20:53:19 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btinternet.com; s=btcpcloud; t=1478206401; bh=cAZ3jYGOstu3IkdckBn/Vg6XXnP5D/wzUwnIJr/bQ/0=; h=Message-ID:From:To:References:Subject:Date:MIME-Version:X-Mailer; b=DwyrW7x6QPuAf9DcTz5y+PkVqiyrRAgpxDbUggrVebLAftm9zSCeTSsGrkk8QzIq7cpQe6R8hOJNdWApoZFErr0ZOMNCs/KP2PlY5mQ98Jxf4TwyKgqlKn/iZiJZsJX++D/2Elim3CnmObKt6CLs5bLdwHuNaeQMboebrzdg5Y4= Message-ID: <9C401CC1F6BE43FFBE56056A1062B525@gnat> From: "Alan Melia" To: References: <581B3A1F.5060609@posteo.de> <581B83FC.6060600@posteo.de> <22185768CF114BE0A22668E235A933A2@gnat> Date: Thu, 3 Nov 2016 20:47:55 -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: 6bb858db23df2b82c4f5a8cb512b45b1 Subject: Re: LF: Smart noise cancelling?!? Content-Type: multipart/alternative; boundary="----=_NextPart_000_0077_01D23613.8D9CD5B0" 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: 6102 Status: O X-Status: X-Keywords: X-UID: 9387 This is a multi-part message in MIME format. ------=_NextPart_000_0077_01D23613.8D9CD5B0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Hi Andy things have changed since then. Real time FFTs were just = beginning to be possible but not many had much experience at that time. = I remember the cleverest stuff I saw was from a graduate student. It = closed down some more traditional work, like an adaptive modem in weeks. = Guessing from the comments on the latest modes now I think there seems = to be little left to achieve in efficiency.=20 Most of us were still thinking in analogue ways then :-)) "Just 'cos it = digital doesn't mean its better" I heard a number of times....we were to = be converted ! Of course a well respected physicist opined in 1900 that there was = little new left to discover in the field. Fortunately for me and the = rest of the profession, he was slightly wrong :-)) =20 Alan G3NYK ----- Original Message -----=20 From: Andy Talbot=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, November 03, 2016 7:45 PM Subject: Re: LF: Smart noise cancelling?!? But surely, when narrowband filtering is in place - as any narrow band = mode will of necessity be doing internally - any wideband non Gaussian = or bursty noise when applied to this narrow filter will eventually = become Gaussian IN THAT BANDWIDTH We first ealised this in teh original QRSS tests with G3PLX back in = the 1990's. 73kHz was full of spikes and 'crud' from teh then existing = Decca signals and other stuff. But when Peter examined the output from = the narrow filters, (the FFT bins) it lookdd like, and appeared to show = itself to be Gaussian. He said it passed the tests for Gaussian noise A mathematician could probably prove that any random non Gaussian = signal if filtered sufficiently narrow in comparison to itsnature, would = end up Gaussian in the filtered bandwidth.=20 In fact, to end up non-Gaussian, it would have to have definite = components repeating at rates very close to the reciprocal of the = bandwidth of the filter. Andy G4JNT ------=_NextPart_000_0077_01D23613.8D9CD5B0 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF
Hi Andy things have changed since then. = Real time=20 FFTs were just beginning to be possible but not many had much experience = at that=20 time. I remember the cleverest stuff I saw was from a graduate student. = It=20 closed down some more traditional work, like an adaptive modem in = weeks.=20 Guessing from the comments on the latest modes now I think there = seems to=20 be little left to achieve in efficiency.
 
Most of us were still thinking in = analogue ways=20 then :-))  "Just 'cos it digital doesn't mean its better" I heard a = number=20 of times....we were to be converted !
 
Of course a well respected physicist = opined in 1900=20 that there was little new left to discover in the field. Fortunately for = me and=20 the rest of the profession, he was slightly wrong :-))  =
 
Alan
G3NYK
 
 
 
 
----- Original Message -----
From:=20 Andy=20 Talbot
Sent: Thursday, November 03, = 2016 7:45=20 PM
Subject: Re: LF: Smart noise=20 cancelling?!?

But surely, when narrowband filtering is in place - as = any narrow=20 band mode will of necessity be doing internally - any wideband non = Gaussian or=20 bursty noise when applied to this narrow filter will eventually become = Gaussian IN THAT BANDWIDTH

We first ealised this in teh original QRSS tests with G3PLX back = in the=20 1990's.   73kHz was full of spikes and 'crud' from teh then = existing=20 Decca signals and other stuff.   But when Peter examined the = output from=20 the narrow filters, (the FFT bins)  it lookdd like, and appeared = to show=20 itself to be Gaussian.   He said it passed the tests for Gaussian = noise

A mathematician could probably prove that any random non Gaussian = signal=20 if filtered sufficiently narrow in comparison to itsnature, would end = up=20 Gaussian in the filtered bandwidth. 

In fact, to end up non-Gaussian, it would have to have definite=20 components repeating at rates very close to the reciprocal of the = bandwidth of=20 the filter.

Andy  G4JNT

 
------=_NextPart_000_0077_01D23613.8D9CD5B0--