Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id w0VFbW7N028128 for ; Wed, 31 Jan 2018 16:37:34 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1eguM8-0006jU-Tf for rs_out_1@blacksheep.org; Wed, 31 Jan 2018 15:31:24 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1eguM8-0006jL-8i for rsgb_lf_group@blacksheep.org; Wed, 31 Jan 2018 15:31:24 +0000 Received: from mail-wm0-x236.google.com ([2a00:1450:400c:c09::236]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1eguM1-0002Wf-Gp for rsgb_lf_group@blacksheep.org; Wed, 31 Jan 2018 15:31:22 +0000 Received: by mail-wm0-x236.google.com with SMTP id r78so8847469wme.0 for ; Wed, 31 Jan 2018 07:31:17 -0800 (PST) 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=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=Z4MwTpo1OKM3XAUwmekZXtPn3lXVV9/m3YZe7t2xgTU=; b=pqrKFSkBeUmMODMzAMlvLGiYFNX7zwS66k4deIUCgZCa+bUmwazbA85jtfyPKOG6K7 ZIy60gNqYTuYKO/fVx9s+Uyt/AsC8/LHxXoScDIDzxmkIouRo/ttEy9JsZvu5/LWCAmX RT2cEhqYtIE1tCSixRHAN3QhUB4jMTROyKuqCRjNg+0HL9zJZG0JaGuwRj0rV/a9D1FW wXeYFuKH98TQqo2/eHQiqEEAE4G1Sw4/zNpjiz3o7Ic9WGxhplxX2pYvV8klX6ZM+oA4 /veQEVbbRTkjQzejRX879u84vp1FagLc61UF4ttx0OMvx8THZkyPq3mzfYFcVy/p4Teo BoxA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=Z4MwTpo1OKM3XAUwmekZXtPn3lXVV9/m3YZe7t2xgTU=; b=G0EwR3nrCtjOL0Col4ZAEaO+pyc99fr7ftlUAbIJEJDXLbV7+3+wjfLzxe/fPmhLyC 2QsrBdhWeb4wIy/DKMr4OxvE3bT3gXDwfimfXmh8EU/O6srFu085i9ZliPT3FvsWlaYY CnzytDzAGlfMwjGqAJUbE1DKe5pXmpedbYFrey5aeaCisPNZevRymZ1PLcdijl8OH755 UtuICadnkojQh1/t++X6DUthAxglt6wyw3k+5TmboosMDCpE9cQC++UiIBJ77EWvA7A7 YCbJIhoOoYGOekEW99UeuGfYa6xiOdtklSUZt1E3pnzcQNDTYdZJ/ckOAZJpptXSJDAO xK6Q== X-Gm-Message-State: AKwxytcxHUxQ4Plj4p0cHOh4R17ljbpU7m0KXm1O/EAYvZGtsQGt7YZT nrgON4OmBTzDJkx/ofQpRos45SfPUXRbpcY6Z/usLw== X-Google-Smtp-Source: AH8x225IOCqP6rp3BJ4lN1EBbn/G7FM/hQrJzM+kSbM7RS4pI32jTDwQ8OkbmvFegl1aDDXwX/JSu6P9zfYxNrW3iYE= X-Received: by 10.80.165.152 with SMTP id a24mr59090210edc.289.1517412676716; Wed, 31 Jan 2018 07:31:16 -0800 (PST) MIME-Version: 1.0 Received: by 10.80.179.198 with HTTP; Wed, 31 Jan 2018 07:31:16 -0800 (PST) In-Reply-To: <1748837630.20180131150955@gmail.com> References: <1371247928.20180126134524@gmail.com> <2960070.Q1UJDuno2A@x220> <2496850.J398JjXP83@x220> <1748837630.20180131150955@gmail.com> From: Andy Talbot Date: Wed, 31 Jan 2018 15:31:16 +0000 Message-ID: To: LineOne Cc: Chris Wilson X-Spam-Score: 1.0 (+) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: If you only have supply of 0/5V you cannot have a negative '0' level. If your scope shows it, then it is possible your scope ground is not connected properly yo the -ve rail but instead to somehting further back showing a small 0.5V drop or teh scope needs setting up [...] Content analysis details: (1.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (andy.g4jnt[at]gmail.com) 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid 1.0 FREEMAIL_REPLY From and body contain different freemails X-Scan-Signature: f7f918e40888a44a70dddae14bd6a529 Subject: Re: LF: Softrock RX divider IC problem, unexpected frequency out Content-Type: multipart/alternative; boundary="f403045c19fc92cda20564142ba6" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,HTML_MESSAGE autolearn=no version=2.63 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 --f403045c19fc92cda20564142ba6 Content-Type: text/plain; charset="UTF-8" If you only have supply of 0/5V you cannot have a negative '0' level. If your scope shows it, then it is possible your scope ground is not connected properly yo the -ve rail but instead to somehting further back showing a small 0.5V drop or teh scope needs setting up Don't worry about it. The wqaveform looks perfect - very nearly 1:1 square wave - its what happens when you do a design properly Now worry about sorting out the divider. Andy On 31 January 2018 at 15:09, Chris Wilson wrote: > > > Hello Claudio, > > > Thanks Claudio, but how do I fix this issue? I can rebuild an F1 > engine, but this is outside my comfort zone :) > > Wednesday, January 31, 2018, 2:34:33 PM, you wrote: > > > > > On Wednesday 31 January 2018 11:19:51 you wrote: > > > >> I don't know I was wondering that myself. Is it significant? > > > > > > > > If the HIGH level is too low the following divider can't divide properly! > > > > > > > > If the LOW level can sink few mA of current from the IC the divider can > be degraded! > > > > > > > > Random divide factor can be a consequence. > > > > > > > > from 74HC74 data sheet, see the VIH and VIL > > > > > > > > > > > > > > Regards > > > > Claudio > > > > > > > > -- > Best regards, > Chris mailto:dead.fets@gmail.com > > > --f403045c19fc92cda20564142ba6 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
If you only have supply of 0/5V you cannot have a negative= '0' level.=C2=A0 =C2=A0
If your scope shows it, then it is pos= sible your scope ground is not connected properly yo the -ve rail but inste= ad to somehting further back showing a small 0.5V drop
or=C2=A0 t= eh scope needs setting up

Don't worry about it= .=C2=A0 The wqaveform looks perfect - very nearly 1:1 square wave - its wha= t happens when you do a design properly
Now worry about sorting o= ut the divider.

Andy


On 31 January 2018 at 15:09, Chr= is Wilson <dead.fets@gmail.com> wrote:


Hello Claudio,


Thanks=C2=A0 Claudio,=C2=A0 but=C2=A0 how=C2=A0 do=C2=A0 I=C2=A0 fix this i= ssue? I can rebuild an F1
engine, but this is outside my comfort zone :)

Wednesday, January 31, 2018, 2:34:33 PM, you wrote:

>
> On Wednesday 31 January 2018 11:19:51 you wrote:
>
>> I don't know I was wondering that myself. Is it significant? >
>
>
> If the HIGH level is too low the following divider can't divide pr= operly!
>
>
>
> If the LOW level can sink few mA of current from the IC=C2=A0 the divi= der can be degraded!
>
>
>
> Random divide factor can be a consequence.
>
>
>
> from 74HC74 data sheet, see the VIH and VIL
>
>
>
>
>
>
> Regards
>
> Claudio
>
>



--
Best regards,
=C2=A0Chris=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 mailto:dead.fets@gmail.com



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