Return-Path: X-Spam-DCC: paranoid 1290; 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=-0.4 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, FORGED_AOL_TAGS,HTML_30_40,HTML_MESSAGE,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 tBAAuoEw007805 for ; Thu, 10 Dec 2015 11:56:50 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1a6yrD-0004Mg-Om for rs_out_1@blacksheep.org; Thu, 10 Dec 2015 10:53:55 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1a6yrD-0004MQ-3z for rsgb_lf_group@blacksheep.org; Thu, 10 Dec 2015 10:53:55 +0000 Received: from omr-a020e.mx.aol.com ([204.29.186.66]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.86) (envelope-from ) id 1a6yq5-0000s4-UA for rsgb_lf_group@blacksheep.org; Thu, 10 Dec 2015 10:53:53 +0000 Received: from mtaomg-mce01.mx.aol.com (mtaomg-mce01.mx.aol.com [172.29.27.207]) by omr-a020e.mx.aol.com (Outbound Mail Relay) with ESMTP id 476E1380008E for ; Thu, 10 Dec 2015 05:52:29 -0500 (EST) Received: from core-afa07c.mail.aol.com (core-afa07.mail.aol.com [172.27.24.7]) by mtaomg-mce01.mx.aol.com (OMAG/Core Interface) with ESMTP id 189D338000084 for ; Thu, 10 Dec 2015 05:52:29 -0500 (EST) References: <8D3014FB7E11F9E-1E50-A26A1@webmail-vm016.sysops.aol.com> To: rsgb_lf_group@blacksheep.org In-Reply-To: <8D3014FB7E11F9E-1E50-A26A1@webmail-vm016.sysops.aol.com> X-MB-Message-Source: WebUI MIME-Version: 1.0 From: Markus Vester X-MB-Message-Type: User X-Mailer: AOL Webmail BASIC Received: from 192.35.17.16 by webmail-vm170.sysops.aol.com (64.12.250.164) with HTTP (WebMailUI); Thu, 10 Dec 2015 05:52:29 -0500 Message-Id: <8D3014FFF98169C-15C4-278D0E@webmail-vm170.sysops.aol.com> X-Originating-IP: [192.35.17.16] Date: Thu, 10 Dec 2015 05:52:28 -0500 x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20150623; t=1449744749; bh=LjMWVL9xiaHsDZvROPOBU8TeHb2wga+m0wpfbktTPrE=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=3mH3SilMjqtfA8gjw4AelK8zyG7gpCrGO3KoG7xIbc0WGmZosOXF//4AmlCycEIL3 Z1/oy+hjTzXNpd3gxCXSMfTVatd1NGPAwEuWScq90wfy8j8dsxwL9D4+XX0SI6CCEX EDEt4ajKN8HIwaoQdc/QI4/6HvM51vx5/2GG+vaU= x-aol-sid: 3039ac1d1bcf5669596d47d1 X-Scan-Signature: 1e15d6d6179985f133b43d42d658878a Subject: Re: LF: DC spike at 1 kHz Content-Type: multipart/alternative; boundary="--------MB_8D3014FFFA8C03C_15C4_5192CB_webmail-vm170.sysops.aol.com" 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 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 5715 This is a multi-part message in MIME format. ----------MB_8D3014FFFA8C03C_15C4_5192CB_webmail-vm170.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Hi=20Andy,=0D=0A=20=20=C2=A0=0D=0A=20=20presumably=C2=A0the=20digital=201=20kHz-= to-baseband=C2=A0conversion=20is=20done=20in=20an=20FPGA=20or=20DSP=20in=20realt= ime.=20The=20associated=20periodic=20processing=20activity=20or=20register=20con= tent=20could=C2=A0lead=20to=20a=C2=A01=20kHz=20component=20radiated=20by=20the=20= FPGA=20itself=20or=20it's=20DC=20power=20lines.=20This=20could=20then=20leak=20i= nto=20the=20analog=20audio=20input=C2=A0to=20the=20ADC.=20Try=20sniffing=20aroun= d=20the=20FPGA=20with=20a=20capacitive=20or=20inductive=20probe.=20=0D=0A=20=20=C2= =A0=0D=0A=20=20Downconverting=C2=A0from=20a=20soundcard=20on=20a=20PC=20in=20sof= tware=C2=A0usually=20does=20not=20suffer=20from=20such=20coherent=20leakage,=20a= s=20there=C2=A0are=20variable=20delays=20due=20to=20buffering=C2=A0and=C2=A0mult= itasking=C2=A0which=20effectively=20remove=C2=A0the=20periodicity=20in=20the=20C= PU=20activity.=C2=A0=C2=A0=0D=0A=20=20=C2=A0=0D=0A=20=20Best=2073,=0D=0A=20=20Ma= rkus=0D=0A=20=20=C2=A0=0D=0A=20=20-----Urspr=C3=BCngliche=20Mitteilung-----=20=0D= =0A=20Von:=20Andy=20Talbot=20<andy.g4jnt@gmail.com>=0D=0A=20An:=20rsgb_lf_= group=20<rsgb_lf_group@blacksheep.org>=0D=0A=20Verschickt:=20Do,=2010=20De= z=202015=2011:23=20am=0D=0A=20Betreff:=20Re:=20LF:=20LF=20EbNaut=20test=20from=20= JN80=20on=20137370=0D=0A=20=0D=0A=20...=0D=0A=20=20=C2=A0=0D=0A=20=20My=20LF=20r= eceiver=20appears=20to=20give=20a=20small=20DC=20spike=20in=20the=20centre=20of=20= the=20=0D=0A=20spectrum=20,=20which=20since=20it=20is=20taking=20input=20at=201k= Hz=20and=20multiplying=20in=20=0D=0A=20firmware=20with=20I/Q=20square=20waves=20= is=20a=20bit=20odd.=20=20=20That=20DC=20term=20wasn't=20=0D=0A=20noticeable=20wh= en=20I=20had=20the=20RF=20amplifier=20previously=20(the=20one=20that=20popped=20= =0D=0A=20with=20strong=20signals)=20but=20now=20gain=20has=20been=20moved=20to=20= 1kHz=20IF,=20the=20line=20=0D=0A=20can=20be=20seen.=20=20=20Perhaps=20an=20RF=20= amplifier=20is=20necessary,=20but=20one=20that=20can=20=0D=0A=20safely=20be=20ov= erloaded=C2=A0=0D=0A=20=20...=0D=0A=20=20=0D=0A=20=0A=0A ----------MB_8D3014FFFA8C03C_15C4_5192CB_webmail-vm170.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; 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=0D=0A=20firmware=20with=20I/Q=20square=20waves=20i= s=20a=20bit=20odd.=20=20=20That=20DC=20term=20wasn't=20
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=0D=0A=20=20=0D=0A= =20 ----------MB_8D3014FFFA8C03C_15C4_5192CB_webmail-vm170.sysops.aol.com--